NOAA Technical Report NOS CO-OPS 043

Ocean Systems Test and Evaluation Program

Test, Evaluation, and Implementation of Current 

Measurement Systems on Aids-To-Navigation

Silver Spring, Maryland

May, 2005

noaa National Oceanic and Atmospheric Administration

U.S. DEPARTMENT OF COMMERCE

National Ocean Service

Center for Operational Oceanographic Products and Services
Center for Operational Oceanographic Products and Services

(CO-OPS)

National Ocean Service (NOS)

National Oceanic and Atmospheric Administration (NOAA)

U.S. Department of Commerce

The CO-OPS mission is to deliver the operational environmental products and services

necessary to support NOAA’s Environmental Stewardship and Environmental Assessment

and Prediction Missions. CO-OPS provides the focus for operationally sound observation

and monitoring capability coupled with environmental predictions to provide the quality data

and information needed to support the cross-cutting NOS Primary Goals of Navigation,

Coastal Communities, Habitat, and Coastal Hazards.

Ocean Systems Test & Evaluation Program

The CO-OPS Ocean Systems Test and Evaluation Program (OSTEP) facilitates the transition

of new technology to an operational status, selecting newly developed sensors or systems

from the research and development community and bringing them to a monitoring setting.

OSTEP provides quantifiable and defensible justifications for the use of existing sensors and

methods for selecting new systems. The program establishes and maintains field reference

facilities where, in cooperation with other agencies facing similar challenges, devices are

examined in a non-operational field setting. Through OSTEP, sensors are evaluated, quality

control procedures developed, and maintenance routines generated. The quality of the

reference systems used in the field is assured by both rigorous traceable calibrations and

redundant sensors.

The Ocean Systems Test & Evaluation Advisory Board consists of:

Mark Bushnell, NOAA/NOS/CO-OPS

Karen Earwaker, NOAA/NOS/CO-OPS

Geoff French, NOAA/NOS/CO-OPS

Ann Gargett, ODU/CCPO

Warren Krug, NOAA/NOS/CO-OPS

Philip Libraro, NOAA/NOS/CO-OPS (Ret.)

W. Douglas Wilson, NOAA/CBO

Bill Burnett, NOAA/NDBC
NOAA Technical Report NOS CO-OPS 043

Ocean Systems Test and Evaluation Program

Test, Evaluation, and Implementation of Current

Measurement Systems on Aids-To-Navigation

Kathryn Thompson Bosley, PhD

Chris McGrath

Jennifer P. Dussault

Mark Bushnell

Michael J. Evans

Geoffrey W. French

Karen Earwaker

May 2005

noaa National Oceanic and Atmospheric Administration

U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration

Carlos M. Gutierrez, Secretary Vice Admiral Conrad C. Lautenbacher, Jr., U.S. Navy (Ret.)

 Undersecretary of Commerce for Oceans and

 Atmosphere and NOAA Administrator

National Ocean Service

Dr. Richard W. Spinrad, Assistant Administrator of the National Oceanic and Atmospheric 

Administration (NOAA) Ocean Services and Coastal Zone Management

 

Center for Operational Oceanographic Products and Services

Michael Szabados, Director
ii

NOTICE

Mention of a commercial company or product does not constitute an

endorsement by NOAA. Use for publicity or advertising purposes of

information from this publication concerning proprietary products or the

results of the tests of such products is not authorized.
iii

CO-OPS STATEMENT OF ACCEPTANCE

CO-OPS management personnel have reviewed this document and concur that the 

evaluated sensor/system, when deployed and implemented as described herein, 

meets the defined requirements and is suitable for operational use. While 

additional testing may lead to superior performance or more economical 

operation, the existing sensor/system configuration is sufficient as described. 
iv
v

TABLE OF CONTENTS 

LIST OF FIGURES...........................................................................................................vii 

LIST OF TABLES ...........................................................................................................xiii 

EXECUTIVE SUMMARY ................................................................................................1 

1.0 INTRODUCTION..........................................................................................................5 

1.1 REQUIREMENTS ..................................................................................................5 

1.2 ACKNOWLEDGMENTS .........................................................................................6 

1.3 PURPOSE AND ORGANIZATION OF THIS REPORT ................................................6 

2.0 DEVELOPMENT OF THE ATON CURRENT MEASUREMENT SYSTEM .........................7 

2.1 THE ATON MOUNT ............................................................................................7 

2.2 THE NORTEK ACOUSTIC DOPPLER PROFILER.....................................................9 

2.3 ON-BUOY POWER BUDGET.................................................................................9 

2.4 THE SHORESIDE STATION.................................................................................10 

2.4.1 Data Collection Platform (DCP)..........................................................10

2.4.2 Communications..................................................................................11

2.4.3 Power ................................................................................................12

2.5 US COAST GUARD APPROVAL..........................................................................12 

2.6 THE PROTOTYPE INSTALLATION ......................................................................13 

2.7 COMPASS PERFORMANCE .................................................................................14 

2.8 VERSION 2 CLAMPARATUS AND NORTEK FIRMWARE......................................17 

3.0 TEST AND EVALUATION ..........................................................................................21 

3.1 TEST & EVALUATION PLAN EVOLUTION..........................................................21 

3.2 NORTEK ADP TESTS AT DAVID TAYLOR TOW TANK ......................................23 

3.3 A 31-DAY COMPARISON OF BUOY “2C” CURRENTS WITH NOS......................26 

3.4 PINEY POINT – A 19-DAY COMPARISON OF CURRENTS FROM ATON “B” AND 

A BOTTOM MOUNT ...........................................................................................31 

3.5 FREEPORT - A COMPARISON OF CURRENT MEASUREMENTS TAKEN BY A

SYSTEM MOUNTED ON A USCG ATON AND IN A BOTTOM PLATFORM ..........41

3.6 A TIDAL CYCLE COMPARISON OF ATONAND SHIP-MOUNTED CURRENT

 MEASUREMENTS NEAR THE MOUTH OF THE CHESAPEAKE BAY ....................54 

4.0 FIELD PROCEDURES.................................................................................................63 

4.1 PRE-DEPLOYMENT ATON RECONNAISSANCE .................................................63 

4.1.1 Safety Precautions...............................................................................63

4.1.2 Establish Local Contact.......................................................................63

4.1.3 Will the Clamparatus fit?.....................................................................64

4.1.4 Can the signal be received at the shore station? ..................................64

4.2 DEPLOYMENT PREPARATION............................................................................64 

4.2.1 Assembly Steps ...................................................................................64

4.2.2 Electronics Diagrams...........................................................................65

4.2.3 Bench Testing......................................................................................67

4.2.3.1 Bench test with AquaPro ........................................................67 

4.2.3.2 Bench test with a 9210 ...........................................................71 

4.2.4 ATON Current Profiler Deployment Packing List.............................74
vi

4.3 INITIAL INSTALLATION .....................................................................................75 

4.3.1 ATON Installation ...............................................................................75

4.3.1.1 Notify Local Contact ..............................................................75 

4.3.1.2 Safety Precautions ..................................................................75 

4.3.1.3 Securing the Clamparatus.......................................................75 

4.3.1.4 Calibrating a Nortek Compass on an ATON..........................76 

4.3.2 Shore Station Installation.....................................................................79

4.3.2.1 Data Collection Platform........................................................79 

4.3.2.2 Power / surge protection.........................................................79 

4.3.2.3 Communications.....................................................................79 

4.3.3 Nortek Settings....................................................................................79

4.3.4 Verifying Data Flow............................................................................80

4.4 PREVENTATIVE MAINTENANCE AND REPAIR VISITS........................................81 

4.4.1 Notify Local Contact ...........................................................................81

4.4.2 Call CORMS .......................................................................................81

4.4.3 Safety Precautions...............................................................................81

4.4.4 Maintenance Checklist ........................................................................81

4.4.5 Deployment and Recovery Logs .........................................................82

4.4.6 Downloading Data from a Nortek on an ATON .................................85

4.4.7 Downloading Data from the Shore Station DCP.................................88

4.4.7.1 Recent.dat ...............................................................................88 

4.4.7.2 Daily Files ..............................................................................88 

4.4.8 Nortek Settings....................................................................................89

4.4.9 Verifying Data Flow............................................................................89

5.0 DATA FLOW.............................................................................................................91 

5.1 FROM THE ATON TO SHORE ............................................................................91 

5.2 TO THE DATA ACQUISITION SYSTEM (DAS)....................................................92 

5.3 DATA FLOW TO CORMS AND TO PRODUCTS...................................................94 

6.0 QUALITY CONTROL.................................................................................................97 

7.0 PRESENT PRODUCT SUITE .....................................................................................103 

8.0 RECOMMENDATIONS AND NEXT STEPS ................................................................105 

ACKNOWLEDGMENTS .....................................................................................................106 

VENDOR CONTACTS........................................................................................................108 

RELATED DOCUMENTS ...................................................................................................109 

ACRONYMS .....................................................................................................................110 

APPENDIX A - AQUADOPP SPECIFICATIONS....................................................................114 

APPENDIX B - CORMS SOPS .........................................................................................116 

APPENDIX C - AQUADOPP ERROR AND STATUS WORDS ................................................126 
vii

LIST OF FIGURES

Figure 1. Design concept for the clamparatus..........................................................7 

Figure 2. The prototype clamparatus deployed on Buoy 2C at the mouth of 

 the Chesapeake Bay ..................................................................................7

Figure 3. The ATON topside electronics box ..........................................................8 

Figure 4. Close-up of the circuit board in the electronics box .................................8 

Figure 5. The Nortek Aquadopp...............................................................................9 

Figure 6. Chief Warrant Officer David Merrill of the buoy tender Frank Drew

gives approval to the clamparatus...........................................................12 

Figure 7. 17 December 2002 deployment of the prototype clamparatus and 

 profiler on ATON buoy 2CH..................................................................13 

Figure 8. Comparison of current directions from the ATON profiler and 

 predictions based on NOS-accepted harmonic constituents ...................14 

Figure 9. Calibration table with current profiler and steel pipe used to ................15 

 simulate the ATON magnetic effect 

Figure 10. Results of running compass calibration software ...................................15 

Figure 11. Compass calibration software screen......................................................16 

Figure 12. Prototype tube attachment mechanism ...................................................17 

Figure 13. Mark II tube attachment..........................................................................18 

Figure 14. Prototype clamp block ............................................................................19 

Figure 15. Mark II (simplified) clamp block............................................................19 

Figure 16. Carriage speed transitions help to identify a timing difference 

 between the current profiler and the carriage .........................................23 

Figure 17. Difference between the reference carriage speed and the speed 

 recorded in bins two and four of the current profiler..............................24 
viii

Figure 18. Tow test data from the current profiler visualized using the Nortek 

 display software. Note the variation of heading and pitch, indicating 

 that the current profiler was not stiffly affixed to the carriage. ..............25 

Figure 19. Location of ATON 2C and the 1999 NOS current survey station 

 used to make comparison predictions.....................................................26 

Figure 20. Deployment of clamparatus on 2C .........................................................27 

Figure 21. Time-series of Aquadopp-measured current speed and predicted 

 current speed ...........................................................................................28 

Figure 22. Time-series of Aquadopp-measured current direction and predicted 

 current direction......................................................................................28 

Figure 23. Direction and speed differences predictions – Nortek............................29 

Figure 24. Scatter plot of speed and direction differences between the 

 ATON-mounted observations and astronomical predictions derived 

 from a nearby station ..............................................................................30 

Figure 25. Relationship between the predicted speed and the difference in 

 direction. Notice that the direction becomes more accurate as the 

speed increases........................................................................................30 

Figure 26. The Potomac River location of the subject intercomparison..................31 

Figure 27. The bottom-mounted current profiler platform was placed to the 

north of the ATON’s watch circle in approximately the same depth 

of water ...................................................................................................32 

Figure 28. Bottom-mount for ADCP with popup buoy for recovery.......................32 

Figure 29. ATON LWB B in the Potomac River.....................................................33 

Figure 30. Time-series of the differences between the speeds recorded by the 

 bottom-mounted current profiler and the ATON-mounted current at 

three depths .............................................................................................34 

Figure 31. Vertical velocity measured by the ATON and bottom-mounted 

 current profilers.......................................................................................35 

Figure 32. Time-series comparison of directions observed by the bottom- and 

 ATON-mount (JD 78-83.........................................................................35 
ix

Figure 33. Time-series comparison of directions observed by the bottom and 

 ATON (JD 93-98 .................................................................................. 36) 

Figure 34. Time-series of the differences in direction between the two current 

 profiler systems. The mean of the absolute value of the difference 

decreases significantly when only higher speed values are onsidered ...37 

Figure 35. Mid-depth (9.5m) current components measured by both mounting 

 Systems ...................................................................................................37 

Figure 36. A weak relationship is seen between differences in direction and the 

 ATON-mounted current profiler heading ...............................................38 

Figure 37. Flood and ebb ATON direction versus direction difference...................39 

Figure 38. Pitch of the Aquadopp versus the difference in direction.......................40 

Figure 39. Seabed mooring with RDI ADCP...........................................................41 

Figure 40. ATON LB B 6 at the mouth of the Freeport River.................................42 

Figure 41. Time-series of current speed and direction from both measurement 

 systems and waves measured by bottom-mount.....................................43 

Figure 42. Time-series of current speed and direction from both measurement 

 systems and wave heights, period, and direction from the bottom 

 mount ......................................................................................................44 

Figure 43. Time-series of current speed and direction from both measurement 

 systems and wave heights, period, and direction from the bottom 

mount ......................................................................................................45 

Figure 44. Time-series of current speed and direction from both measurement 

 systems and wave height, period, and direction measured by the 

 bottom mount..........................................................................................46 

Figure 45. Time-series of differences between the current speed measured by 

 the bottom-mounted current profiler and the current speed from the 

 ATON-mounted sensor...........................................................................47 

Figure 46. Distribution of the current speed difference ...........................................48 

Figure 47. Time-series of current direction and current direction difference at 

 Freeport, TX, 10-25 January 2004..........................................................49 
x

Figure 48. Time-series of current direction and current direction difference, 

 Freeport, TX, 25 January – 9 February 2004..........................................49 

Figure 49. Time-series of current direction and current direction difference, 

 Freeport, TX, 10 February – 24 February 2004......................................50 

Figure 50. Time-series of current direction and current direction difference, 

 Freeport, TX, 25 February – 10 March 2004..........................................50 

Figure 51. Current direction difference versus current speed, Freeport, TX ...........51 

Figure 52. Time-series of the difference between the current direction observed 

 by the bottom- and ATON-mounted systems. The red + indicate all 

points, blue + are from times when the current speed is above onequarter knot.............................................................................................51 

Figure 53. Current direction difference distribution, Freeport, TX .........................52 

Figure 54. Nortek Aquadopp heading versus current direction difference, 

 Freeport, TX............................................................................................52 

Figure 55. Nortek Aquadopp current direction versus current direction 

difference, Freeport, TX .........................................................................53 

Figure 56. Nortek Aquadopp pitch versus current direction difference, 

 Freeport, TX. There is no increase in direction difference for 

increased pitch of the Aquadopp ............................................................53 

Figure 57. Old Dominion University=s research vessel the R/V Fay Slover ............54 

Figure 58. Calibrating the compass of the ATON current measurement 

 system on LB2CH...................................................................................55 

Figure 59. Wind speed, direction, and gust during the experiment observed at 

 the Chesapeake Bay Bridge Tunnel NOS station ...................................55 

Figure 60. Near surface eastward and northward current velocities observed 

 by the hull-mounted ADCP (black) compared to those observed by 

the ATON-mounted system (red) ...........................................................56 

Figure 61. Mid-depth eastward and northward current velocities observed by 

 the hull-mounted ADCP (black) compared to those observed by the 

ATON-mounted system (red) .................................................................57 
xi

Figure 62. Near bottom eastward and northward current velocities observed 

 by the hull-mounted ADCP (black) compared to those observed by 

the ATON-mounted system (red) ...........................................................57 

Figure 63. Near surface current speeds observed by the hull-mounted ADCP 

 (black) compared to those observed by the ATON-mounted system 

(red). The difference is shown in green. A very large vertical 

velocity is observed in this top bin .........................................................58 

 

Figure 64. Depth relationship of the speed difference between ship- and 

 ATON-mounted current measurements..................................................59 

Figure 65. Pitch and roll from both current measurement systems..........................59 

Figure 66. Direction measured by the ship and ATON current profilers and the 

 absolute value of the difference..............................................................60 

Figure 67. Time-series of current direction and current direction difference, 

 Buoy 2CH comparison, May 2004 .........................................................61 

Figure 68. Time-series of current direction difference over depth, Buoy 2CH 

 comparison, May 2004 ...........................................................................61 

Figure 69. 9210 ADCP shoreside unit with telephone modem................................65 

Figure 70. 9210 ADCP shoreside unit with CDMA IP modem...............................66 

Figure 71. Screen shot of Aquapro bench test configuration...................................67 

Figure 72. Screen shot of stop data collection to initiate serial port settings...........68 

Figure 73. Screen shot of load from instrument setting ...........................................68 

Figure 74. Screen shot from Deployment Planning settings....................................69 

Figure 75. Screen shot from Deployment Planning settings....................................69 

Figure 76. Screen shot of Start Data Collection Disk Files......................................70 

Figure 77. Screen shot from online menu ................................................................70 

Figure 78. Screen shot of file transfer ......................................................................71 

Figure 79. Screen shot of file transfer ......................................................................72 
xii

Figure 80. Screen shot of file transfer to connected computer.................................88 

Figure 81. CO-OPS ATON Data Ingestion Process.................................................95 

Figure 82. Chesapeake Bay PORTS® data collection system..................................95 

Figure 83. ATON current data fed to CORMS, current profiler stations are ........101 

 labeled “cu” 

Figure 84. Composite page from PORTS® ............................................................103 
xiii

LIST OF TABLES

Table 1. Valid data set retrieved from bench test ..............................................72 

Table 2. Standard configuration of Nortek ........................................................80 

Table 3. Example of a ARecent.dat@ file.............................................................92 

Table 4. ATON PUFFF......................................................................................93 

Table 5. Sample criteria file...............................................................................98 

Table 6. Sample control file for Buoy 2 CH......................................................99 

Ocean Systems Test and Evaluation Program

Test, Evaluation, and Implementation of 

Current Measurement Systems on 

Aids-To-Navigation

EXECUTIVE SUMMARY

The Physical Oceanographic Real-Time System (PORTS®) is a program of the 

National Ocean Service’s Center for Operational Oceanographic Products and 

Services (NOS/CO-OPS). PORTS® provides real-time marine environmental 

information to support safe and efficient maritime commerce and informed 

coastal resource management. In response to user requests for water current 

information near navigation channels, CO-OPS entered into a partnership with the 

U.S. Coast Guard (USCG) to place current measurement systems on existing 

USCG aids-to-navigation (ATON) buoys. 

This document describes measurement and communication technologies 

employed, the design considerations which ensure that the PORTS® payload does 

not interfere with the primary mission of the buoys, the system test and evaluation 

undertaken, the field procedures for installation, repair and maintenance of the 

systems, the data flow configuration, data quality control procedures, and finally, 

the products generated and disseminated to the public from these current 

measurement systems. 

The system, developed from commercial off-the-shelf (COTS) technology, consists 

of a “clamparatus” (produced by the Oceanscience Group) that secures a current 

profiler (manufactured by Nortek) and electronics box to the buoy. The entire 

package weighs ~200 pounds and is easily deployed using a small boat and a block 

and tackle. Data are sent to shore via spread spectrum radios. Deployments of up 

to seven months have been achieved thanks to the low power consumption of both 

the profiler and radios. This system satisfies the maritime community’s 

requirements for current information within navigation channels, while removing 

the restraints of previous current meter placements, which were limited by cable 

length and the need to stay out of the channel. Underwater cable to shore has long 

been a PORTS® operations weak link because cables are often snagged and broken. 

The ATON-mounted system complies with all USCG requirements. The most 

important concern is ensuring that the system does not interfere with ATON 

utility or maintenance. Other USCG requirements include: a completely battery 

powered system; the ability to deploy and recover with the buoy on station; the 

ability to remove the entire package prior to ATON servicing; the use of all 
2

similar metals and coloration; and minimal alteration of buoy profile and 

characteristics. 

NOS/CO-OPS uses the David Taylor Model Basin to evaluate all acoustic 

Doppler current profilers (ADCPs). Current profilers are mounted to a carriage 

that travels through the tank at precise speeds; the current speed recorded by the 

profiler is then compared to the carriage speed. CO-OPS policy requires that all 

Nortek current profilers used in ATON current measurement system be tow-tested 

at David Taylor before operational use. The David Taylor tests showed a mean 

speed difference of between one centimeter per second (cm/s) and five cm/s, 

depending on the carriage speed and Nortek bin sampled. These results are 

completely in line with current profilers of other manufacturers used by CO-OPS. 

CO-OPS performed a field intercomparison in the Potomac River in about 60 feet 

of water. A bottom-mounted RD Instruments 600 kilohertz (KHz) Workhorse 

ADCP configured with one-meter bins was located approximately 250 meters 

north of the Nortek one-megahertz (MHz) Aquadopp current profiler mounted on 

Buoy B at Piney Point. The Nortek was also configured with one-meter bins. 

Performance was evaluated by comparing the differences in current speed and 

direction. The speeds compare very well, within the anticipated error of 

individual instruments. There was no obvious bias in the ATON, with the mean 

difference being ~ 3 cm/s equals 0.06 knots. The results of comparisons with 

current directions from bottom-mounted current profilers show agreement to 

within +/-21° (standard deviation of 26°) when all data are included. The 

difference improves to 12° when speeds less than one-quarter knot are omitted. 

These results are encouraging, considering three general categories of source of 

differences between the two direction measurements: 1) the error in bottom mount 

direction; 2) the error in ATON direction; and 3) the real environmental 

differences between the respective volumes of water. 

CO-OPS performed another intercomparison at the mouth of the Freeport River, 

Texas, in about 11 meters of water. Data from a bottom-mounted ADCP located 

about 70 meters from an ATON-mounted profiler were analyzed. As in the Piney 

Point comparison, an RD Instruments 600 KHz Workhorse ADCP configured 

with one-meter bins was deployed in a bottom mount to evaluate the Nortek oneMHz Aquadopp profiler mounted on Buoy 6, which was also configured to 

sample one-meter bins. The mean speed difference was ~3 cm/s with no bias 

observed. The Freeport River empties into the Gulf of Mexico and, although the 

flow in the region is not tidally dominated, the rapid reversals in the alongshore 

current are evident in both records of direction. In spite of large directional 

differences at times of current reversal, the mean direction difference was ~15° 

and ~12° when only times with speeds greater than one-quarter knot are 

considered. 
3

The general navigation requirements are for reported current speeds to be accurate 

to within +/- 0.10 knot and direction accurate to within +/- 15° in order to aid in 

the maneuvering of large vessels. The ATON-mounted current measurement 

system, as designed and deployed with the recommended procedures, meets these 

speed and direction requirements. The authors recommend that CO-OPS senior 

management approve the ATON current measurement system for use in PORTS® 

and begin the operational dissemination of the data via the web, phone and text 

pages (CO-OPS homepage). Additional system testing (outlined in Section 8.0) is 

recommended. As presented in this report, the ATON current measurement 

system provides the navigation community with important data in those areas 

where it is impracticable to use either the traditional bottom-mounted or sidelooking current profilers. 

CO-OPS management personnel have reviewed this document and concur that the 

evaluated sensor/system, when deployed and implemented as described, meets the 

defined requirements and is suitable for operational use. While additional testing 

may lead to superior performance or more economical operation, the existing 

sensor/system configuration is sufficient as described. 
4
5

1.0 INTRODUCTION

 1.1 Requirements

CO-OPS developed a real-time current measurement system for placement on 

USCG Aids-To-Navigation (ATON) as an enhancement to the PORTS® Program. 

The requirement for this system came from user requests for current information 

at navigation channels in locations that are either too far from shore for the use of 

a bottom-mounted current profiler system with armored cable or are in danger of 

being dredged up. Users, marine pilots in particular, often require current 

information at the confluence of two navigation channels or in areas where a tight 

turn is needed to stay inside the dredged channel. Through communication with 

local pilots, CO-OPS understands that the basic requirement for current 

information useful to navigators is to know the vertical structure of the current 

speed and direction to within ± 0.10 knot and ± 15° in order to aid in the 

maneuvering of large vessels. 

Implementation of ATON current profilers is an important step forward for 

CO-OPS for two reasons. First, and most important, buoy-mounted current 

profilers allow the measurement of currents at the navigational channels in the 

exact positions that are of most interest to the professional mariner. Before this 

PORTS® enhancement became a reality, the need to limit cable length and to stay 

safely outside of the navigation channel determined the location of a bottommounted current profiler as much as did the users= request for current information. 

Second, there is significant improvement in the availability of current data 

compared to conventional bottom-mounted current measurement systems, which 

have been plagued by underwater cable problems, platform movement, and 

silting. Because divers and underwater cables are not needed, installation and 

operations and maintenance (O&M) costs are reduced considerably. The ATONmounted current profiler systems are a more robust way of delivering critical data 

every six minutes. 

Open-water current information has a variety of uses, in addition to the traditional 

PORTS® objectives of promoting navigation safety and increasing the efficiency 

of maritime commerce. Knowledge of the currents is helpful for search and 

rescue efforts, mitigation of hazardous material (HAZMAT) events, maritime 

accident investigation, planning and implementing dredging, conducting 

environmental impact studies, and engineering design work. 
6

 1.2 Acknowledgments

Thanking key people is traditionally reserved for the end of a document; however, 

in this project, external support was so crucial that it merits a more prominent 

position. This project would not have been possible without the flexibility and 

cooperation of the USCG Fifth District Aids-to-Navigation and Waterways 

Management Branch, particularly John Walters and Chief Warrant Officer 

(CWO) David Merrill, Commanding Officer of the buoy tender Frank Drew. 

Ron George of the Oceanscience Group and Dr. Lee Gordon, formerly of Nortek 

USA, not only developed the system, but handled CO-OPS= changing 

requirements in the early phases of the project. 

 1.3 Purpose and Organization of This Report

This report satisfies the CO-OPS programmatic requirement for documentation of 

new measurement or data collection systems which have been put into operational 

use. The document first describes the basic features and capabilities of the ATON 

current profiler systems, including the measurement and communication 

technologies employed to meet the users= basic requirements, as well as the design 

considerations which ensure that the PORTS® payload does not interfere with the 

primary mission of the buoys (Section 2.0). A description of the evolution of the 

Ocean Systems Test and Evaluation Program (OSTEP) test plan for ATON 

acoustic Doppler current profilers (ADCPs) is provided, followed by a description 

of the results of a variety of tests (Section 3.0). The final five sections of this 

report document are: 

• field procedures for installation, repair and maintenance of the system 

(Section 4.0); 

• the data flow configuration (Section 5.0); 

• data quality control procedures (Section 6.0); 

• the products generated and disseminated to the public from these 

current measurement systems (Section 7.0); 

• recommendations (Section 8.0). 
7

2.0 DEVELOPMENT OF THE ATON CURRENT MEASUREMENT SYSTEM

CO-OPS used commercial off-the-shelf (COTS) hardware and commercial buoymounted meter expertise through contracts with the Oceanscience Group and 

Nortek to integrate this existing technology into a complete instrument package. 

The Oceanscience Group and Nortek were selected because of their success in 

California (Sea Technology, 2000). The Oceanscience Group produced a 

“clamparatus” to secure the sensor and electronics box to the navigation buoy. 

Nortek manufactured the current profiler and also interfaced the data stream to a 

spread spectrum radio. 

 2.1 The ATON Mount

Under a contract with CO-OPS, the Oceanscience Group designed and built the 

Aclamparatus@ mounting device, which provides for easy installation and 

maintenance, while not interfering with the ATON’s primary mission of ensuring 

safe navigation (Figures 1 and 2). 

Most of the clamparatus is aluminum, providing strength without excess weight. 

The tube, which holds the current profiler and protects the profiler’s 

power/communications cable, is made of fiberglass reinforced with additional 

Figure 1. Design concept for the 

clamparatus—the mount to attach the 

current profiler system to an ATON 

Figure 2. The prototype clamparatus 

deployed on Buoy 2C at the mouth of the 

Chesapeake Bay 
8

poured resin. The self-contained, watertight electronics box contains the radio 

modem, circuitry, and enough batteries to allow for six- to eight-month service 

intervals (Figures 3 and 4). Nortek, manufacturer of the current profiler, also 

designed and built the circuit board. 

Figure 3. The ATON topside electronics box

Figure 4. Close-up of the circuit board 

in the electronics box 
9

The radio is a MaxStream X-stream PGK 900 MHz spread spectrum transceiver, 

which was also chosen for power considerations. The sensor and communications 

are completely powered by two 12-volt (V) D-cell battery packs placed in 

parallel. At present power consumption rates, CO-OPS estimates that more than 

six months of six-minute current profile sampling and data transmission are 

possible before battery replacement is necessary. 

 2.2 The Nortek Acoustic Doppler Profiler 

The current meter is a Nortek Aquadopp profiler (current profiler), selected for 

compact size and low power consumption (Figure 5). The Aquadopp profiler 

measures the current profile in water using acoustic Doppler technology. The 

current profiler uses three acoustic beams slanted at 25° to measure the current 

profile in a user-selectable number of cells. Generally, CO-OPS uses one-meter 

bins and collects as many bins as a station’s water depth allows. The current 

profiler has internal tilt and compass sensors and a high-resolution pressure sensor 

(See Appendix A - Aquadopp Specifications). 

 2.3 On-Buoy Power Budget

PROFILER. The current buoy systems are deployed for a period of six months 

with a profiler interval of six minutes and an averaging interval of five minutes. 

The profiler will take 43,200 measurements, and each profile will consist of 149 

bytes. The estimated energy used by the profiler for this duration is 369.9 watthours (WH). 

Figure 5. The Nortek Aquadopp 
10

MODEM. The 9XStream modem on the buoy is set with a baud rate of 2400 bits 

per second (bps) and has an average transmit time of 0.66 second for a profile 

consisting of 149 bytes. During a transmission the modem draws a current of 150 

milliamps (mA). The modem will be in sleep mode for an estimated 336.8 seconds 

per six-minute profiler interval and will draw a current of one mA while in this 

mode. The estimated energy used by the modem for these profiler settings is 303.9 

WH. The total energy used by the buoy system for a six-month time period with 

the settings outlined above will be 673.8 WH. 

 2.4 The Shoreside Station 

 2.4.1 Data Collection Platform (DCP) 

The data collection platform (DCP) used with the ATON ADCP is manufactured 

by Sutron Corporation and is part of the Xpert family of DCPs. The model 9210 

is based on the Intel 486 microprocessor using the Microsoft Windows CE 

operating system. The unit has integrated analog and digital input-output (I/O) 

modules, three RS-232 serial ports, an SDI-12 port and an I2C port for additional 

I/O modules. The unit is packaged in a small aluminum case 11" by 6" by 3". 

The DCP performs a number of self-tests on its internal systems while powering 

up; any errors are displayed on the front panel Liquid Crystal Display (LCD) and 

recorded in the system logs. After the self-tests, the system reads the setup file 

implementing the AquaPro.sll (Sutron Dynamic Linked Library), the software 

which performs the following: 

■ Sets the recording options, (daily, weekly recent, and/or time sync) 

■ Sets COM ports and baud rates 

■ Wakes up the MaxStream radio on the buoy 

■ Establishes communications with the profiler 

■ Sets the profiler time and date 

■ Sets the profiler parameters (these settings are taken from the 

 buoy.cfg file on the DCP) 

■ Starts the profiler 

■ Establishes the following files on the DCP storage card: 

• MMDDYYYYHHMMSS.hdr - American Standard Code for 

Information Interchange (ASCII) text file based on the Buoy.cfg 

file that lists the profiler=s parameters 

• MMDDYYYYHHMMSS.cfg - a copy of the Buoy.cfg file 

• MMDDYYYYHHMMSS.prf - raw profiler data 

■ Starts polling the radio serial port every three seconds. Every six 

minutes the profiler sends the raw data to the DCP. When the DCP 

receives the data the following actions are taken: 

 Received message length is compared to the expected message length. 
11

 If the message is complete: 

 The raw message is copied to the MMDDYYYYHHMMSS.prf file. 

 The raw message is converted to ASCII. 

 A copy of the raw ASCII data is placed in the Recent.dat file. 

 The raw ASCII data are appended to the MMDDYYYY.dat file. 

 If the message length is not complete: 

 The raw message is appended to the BadData.dat file. 

 The time the data were received, the message length, and an error 

flag are written to the BadTime.dat file. 

 If a message is not received within a given time frame: 

 The time and date are taken from the DCP, and an ASCII file is 

written with that time and date and copied to the Recent.dat file. 

 All data fields in the file are set to zero. 

 The file is also to the appended to the MMDDYYYY.dat file. 

 2.4.2 Communications

Shore Station to Buoy. The shore stations use 9XStream, 24XStream, or the XTend radio modems from MaxStream to communicate with the buoy-mount 

systems. The 9XStream radio modems operate between 902 and 928 MHz, 

implementing a frequency-hopping spread spectrum modulation technique with a 

maximum transmit power of 140 milliwatts (mW). The 24XStream radio 

modems operate between 2.4 and 2.4835 gigahertz (GHz), also implementing a 

frequency-hopping spread spectrum modulation technique with a maximum 

transmit power of 50 mW. The 9XStream and 24XStream modems operate at a 

baud rate of 2400 bps, with four retries to provide reliable communication over 

the distance required. The X-Tend radio modems operate between 902 and 928 

MHz implementing a frequency-hopping spread spectrum modulation technique 

and have a maximum transmit power of 1W. 

Data Collection. Every six minutes the DCP at the shore station is polled for a 

copy of the Recent.dat file through either a Raven Code Division Multiple Access 

(CDMA) Internet Protocol (IP) modem from AirLink Communications or an 

Xpert voice modem from Sutron. In the future, if a phone connection is 

unavailable, Geostationary Operational Environmental Satellite (GOES) 

communications will be used as the primary pathway for data collection with the 

IP modem as a backup. The Raven CDMA modems have an assigned static IP 

address, which can be polled through the public CDMA/1XRTT (radio 

transmission technology) network. They support dual band operation for both 

800 MHz cellular and 1.9 GHz PCS (personal communication system) bands. 

The CDMA modems are connected to the 9210s through an RS232 DB-9F 

interface and operate at a baud rate of 115200 bps. 
12

Figure 6. Chief Warrant Officer David Merrill of 

the buoy tender Frank Drew gives approval to the 

clamparatus 

 2.4.3 Power

The 9210 and the radio frequency (RF) radio run off a 12V 38 ampere-hours (ah) 

battery, which is charged by a 30W solar panel through a 12V, eight ah solid state 

photovoltaic (PV) charge controller. The Raven CDMA runs off of a 12V 38ah 

battery, which is charged by a 30W solar panel through a 12V, eight ah solid state 

PV charge controller. 

 2.5 US Coast Guard Approval

CO-OPS is committed to ensuring that the primary mission of the USCG buoys is 

not impeded in any way by ATON utility and/or maintenance. The importance of 

this cannot be overstated. To that end, many steps were taken, including: 

• building a package that could be deployed and recovered while the buoy is 

on station so that the entire package can (and will) be removed prior to 

servicing the buoy; 

• isolating dissimilar metals and matching coloration; and 

• designing for minimal alteration of the buoy profile and characteristics. 

The total package weighs approximately 200 pounds, therefore it should have 

negligible effect when deployed on a 12,000 -plus pound, 8' by 26' navigation buoy. 

Other precautions include: 1) the buoy optics are lowered by only 0.1 inch, and 2) 

the buoy tilt is increased by only one-half degree. 

CO-OPS met with the USCG Fifth District 

Aids-to-Navigation and Waterways 

Management Branch several times during 

this project. Initial meetings were briefings 

in order to obtain USCG approval to 

proceed. After the prototype system was 

built, CO-OPS installed it on an 8' x 26' 

ATON at the Portsmouth, Virginia USCG 

buoy yard, giving all USCG ATON Branch 

personnel an opportunity to inspect and 

comment on the system (Figure 6). 
13

 2.6 The Prototype Installation

The requirement for easy deployment/recovery resulted in the decision to assemble all 

pieces of the system shoreside to eliminate the possibility of water damage caused by 

opening the electronics box while on the buoy. The maiden deployment of the entire 

package took five people one hour on a rather windy day in December 2002 (Figure 7). 

Chesapeake Channel Lighted Bell Buoy 2C (LBB 2C) at the mouth of the Bay was 

chosen for the prototype installation due to its proximity to the CO-OPS Facility in 

Chesapeake, Virginia and availability of shore communications. Additionally, since this 

is the most open water of all the Chesapeake Bay sites, the prototype will likely face a 

full range of deployment challenges at this location. 

Figure 7. 17 December 2002 deployment of the prototype clamparatus and profile on buoy 2C 
14

 2.7 Compass Performance 

In order to assess the system’s performance, one-month of current data 

(17 October – 21 November 2003) was compared to NOS harmonic tidal current 

predictions from a station 0.75 mile away. A calibration accuracy issue with the 

compass became obvious immediately because, at any given time, the current 

direction from predictions and that observed by the ATON system could be ±180° 

different (Figure 8). Even considering the natural differences between predictions 

and observations, which include the effect of wind and runoff, the strong (nonlinear) magnetic effect of the buoy=s steel hull was clear. 

In response to CO-OPS’ concerns, Nortek designed and installed a current profiler 

firmware enhancement, which enabled CO-OPS to perform compass calibrations. 

CO-OPS began assessing the capability of this calibration by studying the effect 

of a large steel pipe placed in the field of the Nortek current profiler (Figure 9). 

Preliminary in-lab experiments were very promising (Figure 10), since much of 

the magnetic deviation was removed by running the calibration procedure. 

Figure 8. Comparison of current directions from the ATON profiler and predictions 

based on NOS-accepted harmonic constituents 
15

Figure 9. Calibration table with 

current profiler and steel pipe used to

simulate the ATON’s magnetic effect 

Figure 10. Results of running compass calibration software
16

Nortek Compass Calibration Firmware. Originally there was no way to 

calibrate the Aquadopp=s compass in order to remove the effect of nearby 

magnetic objects. In response to CO-OPS’ findings, Nortek provided revised 

firmware. The “compass” in the Nortek Aquadopp is actually a three-dimensional 

(3D) magnetometer plus a tilt sensor. Thus, there are two transformations 

performed. The first is a one-time magnetometer correction. The routine 

performed by the magnetometer correction firmware can be expressed as: 

[Mx', My', Mz'] = [Mxo, Myo, Mzo] + T × [Mx, My, Mz] 

where the [Mx, My, Mz] is the internal 3D magnetometer reading at any given 

point and [Mx',My',Mz'] are the readings after correction. The matrix T is 

determined at the Nortek factory during a routine magnetometer calibration, 

which is designed to ensure that all components are properly scaled and 

cross-coupling between the components is removed. The offsets [Mxo, Myo, Mzo] 

are determined during the in-situ compass calibration, in which the entire ATON 

with the current profiler attached is rotated through 360° several times (Figure 

11). The purpose is to remove the effect of “hard iron” (i.e. magnetic fields) in 

the mounting structure. 

Figure 11. Compass calibration software 
17

Figure 12. Prototype tube attachment 

mechanism

The second transformation occurs on a sample-by-sample basis. To calculate the 

compass direction from the magnetometer and tilt sensor readings, the following 

relationship is used: 

 [Mhx, Mhy, Mx] = G (pitch, roll) × [Mx',My', Mz'] => H=atan (Mhy, Mhx) 

The magnetometer readings are first transformed into an earth-referenced system 

using the pitch and roll sensor. Then the heading is calculated from Mhx and Mhy, 

which are magnetometer components perpendicular to the gravity vector. This 

calculation assumes that the ATON was perfectly “flat” (zero pitch and roll) 

during the compass calibration spin, which may be the source of some residual 

error. CO-OPS continues to work with Nortek to determine the magnitude of this 

compass calibration error. 

CO-OPS and Nortek also continue to explore the collection of a GPS compass 

reading during the calibration spin to build a correction table, since a GPS 

compass does not use the relationship to the Earth’s magnetic field. Work must 

be done to transform such an externally-generated correction table into the 

correction terms used when measuring the current profile. 

 2.8 Version 2 Clamparatus and Nortek Firmware

CO-OPS began working with Oceanscience Group to improve the prototype 

clamparatus when the current direction accuracy became suspect, and in response to 

the “ease of deployment” issues of the prototype. First, the fiberglass tube that holds 

the Nortek current profiler was extended by two feet in order to move the sensor’s 

compass farther away from the ATON’s steel hull. The method of attaching the tube 

was changed dramatically. Initially the tube was secured with 12 bolts holding a 

curved plate over the tube at the approximate water line (Figure 12). 
18

The new clamparatus uses three large U-bolts isolated in rubber bushings (Figure 

13). The additional length makes deployment and recovery slightly more 

cumbersome, but does not change the package’s weight significantly, partially 

because of the removal of the heavy tube clamping mechanism. 

The use of a simpler and more watertight electronics box and the increase in 

battery capacity that the new box allowed resulted in a significant increase in 

weight (150 pounds [lbs] to 200 lbs). 

Another improvement between the prototype and the production clamparatus is 

the use of a simpler clamping mechanism. The prototype clamp block had several 

moving parts which could be easily dropped in the water. Additionally, the 

original clamp block required the use of shims to fill the variable space inside an 

ATON lifting eye, which was inconvenient and time-consuming (Figure 14). The 

new mechanism is adjusted by tightening three stainless steel bolts (Figure 15). 

Figure 13. Mark II tube attachment (the electronics box lid is in the foreground)
19

Figure 14. Prototype clamp block 

Figure 15. Mark II (simplified) clamp block
20
21

3.0 TEST AND EVALUATION

 3.1 Test & Evaluation Plan Evolution 

Initially, the development of the ATON ADCP was neither a directed CO-OPS 

effort nor a PORTS® partner-requested capability. Rather, OSTEP identified it 

as a potentially rewarding technology, first described by Nortek and 

Oceanscience Group in the October 2001 issue of the journal Sea Technology. 

The Maryland Port Authority (MPA) accepted the developmental cost and the 

associated risk, without the requirement of a fully-developed test plan. 

Additionally, the USCG had the option of declining support if the ATON ADCP 

was found to hinder the primary ATON purpose of safe navigation. CO-OPS is 

grateful to the MPA for such earnest interest and for assuming this risk. 

Acceptance of a sensor for OSTEP testing requires that three fundamental 

conditions are met: 

• Need. There must be a requirement within CO-OPS for the 

sensor/system. 

• Funding. Funds supporting the project must be in place. 

• Sufficient human resources. CO-OPS staff must have adequate time to 

conduct test and evaluation. 

These conditions were satisfied for the test and evaluation of the ATON ADCP. 

Within OSTEP, certain testing precepts have been established: 

• Testing by external partners with OSTEP guidance and input is highly 

desirable. Many institutions have expertise and similar interests in 

sensor/system evaluation. It is cost effective and strengthens the overall 

findings when partnership synergies are exploited. 

• Review of OSTEP test plans and results by external partners is also highly 

desirable, for the same reasons. 

• Tests results provided to OSTEP by the manufacturer of the sensor/system 

being tested are desired, but they are not sufficient to justify acceptance 

for operational purposes. 

After receiving MPA support for the ATON ADCP concept, CO-OPS planned the 

testing to ensure that the following requirements were met: 

• Field references comprised of existing operational current measurement 

technologies must be established at a variety of locations. 

• Reported current velocities must be sufficient to meet navigational 

requirements. Accuracies must be similar to bottom-mounted ADCP 

accuracies, with an understanding that they would likely be less accurate. 

• Maintenance cycles must be required at six-month intervals or greater. 

• Hardware installation must be a safe and simple, small boat, fair weather operation. 
22

• Installation and maintenance costs must be acceptable to CO-OPS and 

PORTS® partners. 

• Overall data distribution reliability must be as good or better than cabled 

deployments (in the long term). Valued data at locations beyond cabled 

ranges must have a favorable cost/benefit ratio. 

• Hardware life expectancies in the harsh marine environment must meet 

operational requirements and must survive most episodes of corrosion, 

storms, vandalism, etc. 

• The vendors must be reliable to the extent that anticipated product 

delivery is a probable outcome. There is no joy in unsupported hardware. 

Planned testing followed decades of acceptance testing for a variety of ADCPs 

from several manufacturers. Well-defined acceptance tests were conducted at the 

Naval Surface Warfare Command (NSWC), Carderock Division (David Taylor) 

and in the field. Standardized quality control/quality assurance (QA/QC) 

evaluation by the NOS/CO-OPS National Current Observation Program (NCOP) 

was planned and executed. Operational QA/QC criteria and procedures for the 

Continuous Operational Real-time Monitoring System (CORMS) were developed 

using the standards set for existing PORTS® current observation stations. In 

summary, CO-OPS has evaluated this current measurement technology as 

rigorously as it has all previous NCOP current observation technologies. 

Test plans were intentionally flexible, given the unique deployment of COTS 

sensors. As with many OSTEP projects, reactive testing based upon previous 

results was envisioned in order to maximize strained resources. 
23

3.2 Nortek ADP Tests at David Taylor Tow Tank

The David Taylor Model Basin consists of several hydraulic facilities, including 

two towing basins and a circulating water channel. NOS uses the towing basins 

to test its current profilers. The current meters are mounted to a carriage that 

travels the tank at a precise speed—the current speed is then compared to the 

carriage speed. 

CO-OPS policy dictates that all current profilers must be towed at David Taylor before 

operational use; therefore all Nortek Aquadopps are tow tested at David Taylor. The 

following results are from two AQP (S/N 1084 and 1093) that were towed on 10 July 

2003. They are indicative of the results from all the other AQP tows. 

The carriage and Aquadopp speed measurements were compared using Aquadopp 

bins one through four. For S/N 1084 the mean speed difference of bin two was 

-0.17 cm/s at a nominal carriage speed of 40 cm/s and 1.45 cm/s when the carriage 

was traveling 80 cm/s (Figure 16). For S/N 1092 the mean speed difference of bin 

four was -1.23 cm/s at a nominal carriage speed of 40 cm/s and -2.28 cm/s when the 

carriage was traveling 80 cm/s (Figure 17). These differences are completely in 

line with differences observed during David Taylor tow tests of both RDI and 

SonTek current profilers (Dr. Eddie Shih, personal communication). 

Figure 16. Carriage speed transitions help to identify a timing difference between the 

current profiler and the carriage 

NORTEK 1084 (7/10/2003) 

Mean speed difference with standard deviation vs Carriage speed 

-15

-10

-5

0

5

10

15

0 10 20 30 40 50 60 70 80 90 100

Carriage speed (cm/s) 

Mean speed difference (Sensor-Carriage, cm/s) 

cell 2 cell 4 Nortek specs Nortek specs

Cells are clustered around the reference carriage 

speeds. 

+ 1% + 0.5 cm/s

Mean + standard deviation
24

It should be noted that large difference spikes during carriage reversal occurred in 

some of the early tows. These data points were removed before calculating the 

mean differences shown in Figure 17. The spikes can be explained by the fact 

that the carriage is on a track above the water and the current profiler is 

submerged in the tow tank. This characteristic is seen with all current profilers 

tested at this facility. The carriage can stop and have a speed of exactly 0 m/s 

whereas the water will always be moving, even when the carriage has stopped. 

This results in a carriage speed of exactly 0 m/s at times, while the Nortek speed 

does not go to 0 m/s. 

Analysis of the current profiler data using Nortek’s display software reveals a 

need for refinement of the Aquadopp mounting system. The current profiler must 

not have been totally secure during the early test, since heading, pitch, and roll all 

vary during the tow test (Figure 18). 

Figure 17. Difference between the reference carriage speed and the speed recorded in 

bins two and four of the current profiler 

Nortek 1092 (7/10/2003) 

Mean speed difference with standard deviation vs Carriage speed

-15

-10

-5

0

5

10

15

0 20 40 60 80 100 120

Carriage speed (cm/s)

Mean speed difference (Sensor-Carriage, cm/s)

cell 1 cell 2 cell 3 cell 4 Nortek specs Nortek specs

Cells are clustered around the reference carriage 

speeds.

+ 1% + 0.5 cm/s

Mean + standard deviation 
25

Figure 18. Tow test data from the current profiler visualized using the Nortek display software. Note the 

variation of heading and pitch, indicating that the current profiler was not stiffly affixed to the carriage. 
26

3.3 A 31-Day Comparison of Buoy “2C” Currents with NOS 

The NOS Predictions. In 1999 CO-OPS performed a current survey in the 

Lower Chesapeake Bay. The harmonic predictions used for this comparison are 

from a station located 0.76 nautical mile (nm) from Buoy “2C” (Figure 19). The 

1999 station was a bottom-mounted RDI Workhorse. It is important to notice 

that, although the stations are relatively close, the 1999 station is closer to the 

dredged channel, which likely restricts the flow on ebb. 

The Nortek Data. On 16 October 2003, with Brad Wynn at the helm of the 

NOAA Bay Tide, a crew consisting of John Abbitt, Kate Bosley, Steve O’Malley, 

and John Stepnowski installed the latest version of Oceanscience Group’s 

clamparatus on Buoy “2C” (Figure 20). On 21 November Kate Bosley, Dave 

Hatcher, and Brad Wynn returned to the buoy to retrieve data stored in the current 

profiler. This step was necessary because shoreside problems had produced data 

gaps, and because the radios did not have enough bandwidth to transfer large data 

files. Three data files were linked together to produce a 31-day time series of 

current profiles. Midway in the deployment the clock was reset to Greenwich 

Mean Time (GMT). 

Figure 19. Location of ATON 2C and the 1999 NOS current survey station used to make 

comparison predictions
27

Results. The five-day period shown in Figures 21-23 was chosen as a 

representative comparison of the month-long series at 2C. There are clear times 

of tidally dominated flow (e.g. day 308) and other times when wind-driven events 

dominate (e.g. day 309.5). The largest directional differences occur at slack tide, 

which is to be expected since the flow is weak and variable. The directional 

differences during peak flood and ebb warrant further investigation. 

The mean of the absolute value of the difference between the predicted direction 

and the Nortek-observed direction is 50.2° for the 31-day deployment (Figure 23). 

Although the differences do cluster around ± 30°, there is considerable scatter in 

the differences (standard deviation [s.d.] is 66.1°) (Figures 24 and 25). 

Again it is important to note that these comparisons use astronomical predictions 

as the standard of comparison. Concurrent observations from two different 

current measurement systems are needed to fully investigate the ATON system. 

Figure 20. Deployment of clamparatus on 2C 
28

Figure 22. Time-series of Aquadopp-measured current direction and predicted 

current direction 

Figure 21. Time-series of Aquadopp-measured current speed and predicted current 

speed 
29

Figure 23. Predictions – ATON direction and speed differences 
30

Figure 24. Scatter plot of speed and direction differences between the 

ATON-mounted observations and astronomical predictions derived from 

a nearby station 

Figure 25. Relationship between the predicted speed and the 

difference in direction. Notice that the direction becomes more accurate 

as the speed increases. 
31

 3.4 Piney Point – A 19-Day Comparison of Currents from ATON 

 “B” and a Bottom Mount 

CO-OPS performed an intercomparison of ATON- and bottom-mounted current 

profilers in the first quarter of 2004, because concurrent observations from two 

different measurement systems are needed to fully evaluate the ATON system. The 

Chesapeake Bay test site selected was ATON B in the Potomac River. The station was 

selected because it is a reasonable depth for a bottom mount, the flow is assumed to be 

nearly rectilinear, and the ATON is less than a mile from the shore station, potentially 

providing a good radio link. 

The Bottom-Mounted Current Profiler. CO-OPS’ Coastal and Estuarine Current 

Analysis Team (CECAT) deployed a 600- KHz RDI Workhorse in a trawl-resistant 

platform. The current profiler was placed ~ 250 yards to the north and outside the 

watch circle of the ATON (Figure 26 and 27). The Workhorse was set to report a value 

every six minutes in one-meter bins throughout the water column. 

Figure 26. The Potomac River location of the subject intercomparison
32

Figure 27. The bottom-mounted current profiler platform was placed to the north of 

the ATON’s watch circle in approximately the same depth of water 

Figure 28. Bottom-mount for ADCP with pop-up buoy for recovery 
33

The ATON Current Profiler. On 17 March 2004 a clamparatus and Nortek current 

profiler were installed on ATON B just off Piney Point in the Potomac River (Figure 

29). The one-MHz profiler was set to average 180 seconds out of the 360-second 

sampling interval. For consistency with the bottom mount, the bin length was set at one 

meter. Approximately 20 days later, data were downloaded directly from the current 

profiler, which was sitting on the ATON. This step was necessary because shoreside 

problems had produced data gaps, and because the radios had insufficient bandwidth to 

transfer large data files. 

Results. CO-OPS began with a comparison of three bins: the shallowest Nortek (3.5 m 

[11.5']), mid-depth (9.5 m [31.2']), and the deepest RDI (15.5 m [44.3']). At these three 

depths the speeds compare very well, within anticipated error of individual instruments 

(Figure 30). There was no obvious bias in ATON current speeds. The mean of the 

absolute value of the speed differences were all ~ 3 cm/s = 0.06 knot. 

Figure 29. ATON LWB B in the Potomac River 
34

As expected, the ATON current measurements were noisier at all levels because of 

ATON motion. Also, the ATON currents exhibited vertical velocities approximately 

ten times greater than those of the bottom mount (Figure 31). 

The current direction measurements from the ATON-mounted system are the focus of 

this comparison. CO-OPS must determine whether the ATON system can provide 

current measurements that meet the requirements of the navigation community. The 

current directions from both the bottom- and ATON-mounted measurements were 

corrected for local variation to degrees true north by subtracting 10.92 from the 

instruments readings. These two five-day segments are representative of the maximum 

differences observed during the time-series (Figures 32 and 33). 

Figure 30. Time-series of the difference between the speeds recorded by the bottommounted current profiler and the ATON current profiler at three depths 
35

Figure 31. Vertical velocity measured by the ATON- and bottom-mounted current 

profilers 

Figure 32. Time-series comparison of directions observed by the bottom and ATON mount 

(JD 78-83) 
36

A comparison of the directions measured by the two systems is encouraging because 

they flood and ebb together, with similar time/direction characteristics, and because 

largest differences occur at the change of tide, when the currents are weak and variable. 

There is, however, no clear pattern (i.e. the ATON direction is not always higher/lower 

on flood/ebb). 

CO-OPS explored several other relationships in search of a parameter that correlated 

well with the difference in direction between the bottom mount and ATON (Figure 34). 

The mean of the absolute value of the difference between the bottom- and ATONmounted observed directions was 21.2° for the 20-day series when all points were 

considered (s.d. is 26.1°). Analyzing only the points when the observed speed is 

greater than 0.25 knots reduced the mean difference to 12.3°. There was considerable 

scatter in the differences (s.d. is 16.3°). 

A plot of the data in velocity space revealed that a higher difference was associated with 

east-west velocity (Figure 35). This may be a result of the predominate wind (and 

therefore) wave direction being along the ~ east/west axis of the Potomac River. Waves 

cause more vertical motion of the buoy and may therefore introduce more velocity error. 

CO-OPS will explore this possibility further using recently collected wave and current 

data from Cape Henry Light Wreck Buoy “2CH”. 

Figure 33. Time-series comparison of directions observed by the bottom and ATON 

mount (JD 93-98) 
37

Figure 35. Mid-depth (9.5 m) current components measured by both mounting 

Figure 34. Time-series of the difference in direction between the two current profiler 

systems. The mean of the absolute value of the difference decreases significantly when 

only higher speed values are considered. 
38

The difference isn’t just related to the direction the buoy is pointed, although there are 

more negative differences when the heading is between 50° and 150° and more positive 

differences when the heading is between 150° and 360° (Figure 36). This hints that 

having the mass of the ATON upstream or downstream of the current profiler may have 

some effect. However, the orientation of the ATON, which is directly driven by flood 

and ebb, doesn’t appear to be related to the direction differences (Figure 37). 

Suspecting that the degree of tilt of the ATON may be a primary indicator of data 

quality, CO-OPS explored the relationship between pitch and error in direction (Figure 

38). The only thing that becomes obvious from this exercise is that the ATON has a 

semi-permanent 5°+ tilt. 

Figure 36. A weak relationship is seen between differences in direction and the ATON-mounted 

current profiler heading 
39

Figure 37. Flood and ebb, ATON direction versus current direction difference 
40

Piney Point Summary. The result of this current profiler mounting system 

comparison is that at speeds greater than 0.25 knot, the average difference between the 

current direction measured by a bottom-mounted system and an ATON-mounted 

system is ~ 12°. It is important to note that there are errors in the directions observed 

by both the bottom- and ATON-mounted current profilers, as well as real directional 

differences caused by horizontal shear in the current field. At first look, no clear linear 

relationship can be identified between the direction difference and heading, pitch, or 

current direction. 

Figure 38. Pitch of the Nortek Aquadopp versus the difference in direction 
41

3.5 Freeport - A Comparison of Current Measurements Taken by a 

System Mounted on a USCG ATON and in a Bottom Platform 

Project Background. CO-OPS partnered with Fugro GEOS to compare two current 

profiler mounting systems near the Freeport Entrance Channel in Texas. This project 

leveraged one of Fugro GEOS’s contracts, Freeport Liquid Natural Gas Development, 

L.P. (who commissioned Fugro GEOS to install an RDI Workhorse ADCP in a seabed 

mooring in self-contained mode) in order to obtain profiles of current speed and 

direction during a six-month period from November 2003 to April 2004 (Figure 39). 

CO-OPS evaluated the direction data from the Nortek profiler and the effectiveness of 

the calibration procedure by comparing them to the direction data from the seabedmounted Workhorse ADCP.

Comparison Configuration. In January 2004 Fugro GEOS and CO-OPS successfully 

installed a clamparatus system on Navigation Buoy 6 at the Freeport Entrance Channel 

(Figure 40). This ATON is approximately 70 meters away from the bottom-mounted 

current profiler, in a water depth of about 11 meters. 

The data from the seabed- and the ATON-mounted current profilers were compared 

over a four-month period, between January and April 2004. A service visit was 

conducted mid-way to change the batteries in the seabed-mounted current profiler and 

to download data from both instruments. Both current profilers were configured to 

record current data in one meter bins over six-minute ensembles. 

Figure 39. Seabed mooring with RDI ADCP 
42

The Workhorse ADCP was also configured to measure waves. This allowed the 

performance of the ATON-mounted Nortek profiler to be evaluated in higher sea states, 

when the buoy is tilted more. A further benefit of the comparison at this location is the 

ability to evaluate system performance in an offshore environment, rather than in a 

protected bay where tidal currents are the dominant feature. 

Preliminary Results. Data from the first two months of the survey are presented here. 

Generally, there is agreement between the current measurements from the two different

mounting systems. The major shifts in current direction are observed in both data sets, 

as well as major current events (Figures 41-44). As expected, the agreement breaks 

down during weak currents, as well as during periods with relatively high waves due to 

current variability. Unlike the comparison that CO-OPS has performed in the Potomac 

River of the Chesapeake Bay, currents at the mouth of the Freeport River are not 

predominately tidal. The largest signal in current direction results from changes in the 

offshore current regime.

Figure 40. ATON LBB 6 at the mouth of the 

Freeport River 
43

Figure 41. Time-series of current speed and direction from both measurement systems and 

waves measured by the bottom mount
44

Figure 42. Time-series of current speed and direction from both measurement systems and wave 

height, period, and direction from the bottom mount
45

Figure 43. Time-series of current speed and direction from both measurement systems and wave height, 

period, and direction measured by the bottom mount
46

Figure 44. Time-series of current speed and direction from both measurement systems and wave 

height, period and direction measured by the bottom mount
47

Focusing first on the observed current speed, CO-OPS found that the mean speed 

difference for the top usable ATON bin (3.5 m) is 3.1 (cm/s) with a 2.9 cm/s s.d. There

is small bin-to-bin variation in the speed differences, with the middle depth bin 

showing the least difference between the bottom mount and ATON (Figure 45), where 

both sensors are most likely to be measuring the same physical volume. The speed 

differences are nearly evenly distributed about zero, thus no large bias exists in either of 

the current profiler speed measurements (Figure 46). 

Figure 45. Time-series of differences between the current speed measured by the 

bottom-mounted current profiler and the current speed from the ATON-mounted sensor
48

As with previous studies, the most concern is about the agreement between the 

current direction measured by the sensors on the two different mounting systems. 

Similar general current patterns are observed by both measurement systems 

(Figures 47-50). The data show that the difference between the directions 

increases at low speeds (Figure 51). For the 3.5 m bin, the mean of the absolute 

value of the difference in six-minute directions is 13.4° (s.d. = 15.1°) when all 60 

days are considered, and 11.5° (s.d. drops to 10.1°) when only points with speeds 

greater than 0.25 knot are tabulated (Figure 52). 

Although the asymmetry around zero was slightly more for the directional 

differences than seen in the current speed difference, a large bias was not evident 

in either of the current direction measurements (Figure 53). The distribution 

showed that 69% of the directional differences were within +/- 10° of zero and 

89% of the differences were less than or equal to +/- 15°. No single predictor of 

directional difference was found. 

ATON heading, observed current direction, and pitch were all investigated, but 

none had a useful regression relationship that could be used to adjust the ATON 

current direction prior to data dissemination (Figures 54-56).

Figure 46. Distribution of the current speed differences 
49

Figure 47. Time-series of current direction difference at Freeport, Texas, 10-25 January 2004 

Figure 48. Time-series of current direction and direction difference, Freeport, Texas, 

25 January-9 February 2004 
50

Figure 49. Time-series of current direction and direction difference, Freeport, 

Texas, 10-24 February 2004 

Figure 50. Time-series of current direction and direction difference, Freeport, Texas, 

25 February – 10 March 2004 
51

Figure 51. Current direction difference versus current speed, Freeport, Texas 

Figure 52. Time-series of the difference between the current direction observed by 

the bottom- and ATON-mounted systems. The red + indicate all points, the blue + are 

from times when the current speed is above one-quarter knot.
52

Figure 53. Current direction difference distribution, Freeport, Texas 

Figure 54. Nortek Aquadopp heading versus current direction difference, Freeport, 

Texas 
53

Figure 56. Nortek Aquadopp pitch versus direction difference, Freeport, TX. There is no 

increase in direction difference for increased pitch of the Aquadopp.

Figure 55. Nortek Aquadopp current direction versus direction difference, 

Freeport, Texas 
54

3.6 A Tidal Cycle Comparison of ATON- and Ship-Mounted 

Current Measurements Near the Mouth of the Chesapeake Bay

Project Background. CO-OPS conducted an experiment using a ship hullmounted current profiler, in addition to two intercomparisons with bottommounted current profilers. CO-OPS purchased ship time on the Old Dominion 

University (ODU) research vessel the R/V Fay Slover (Figure 57). ODU’s Center 

for Coastal Physical Oceanography scientists obtained profiles of current speed 

and direction during a complete tidal cycle near spring tide in May 2004. Data 

from a hull-mounted RD Instruments Workhorse ADCP were used to evaluate the 

direction data from the ATON system and the effectiveness of the compass 

calibration procedure. 

Comparison Configuration. CO-OPS installed a clamparatus system on the 

Cape Henry Wreck Lighted Buoy 2CH at the Chesapeake Bay entrance (Figure 

58). This ATON is at approximately 36.9592° north (N), 76.0128° west (W) in 

about 13 m of water. On 17-18 May 2004 the R/V Fay Slover moored near 

36.9596° N, 76.0129° W, just to the NW of LB 2CH and collected 24 hours of 

continuous current profiles. A 600-KHz RDI Workhorse ADCP mounted in the 

hull of the R/V Fay Slover was used to obtain the current profiles. Both current 

profilers were configured to record current data in one meter bins over six-minute 

ensembles.

This experiment was planned to catch the spring tidal currents for this area, which 

were predicted for 17-18 May 2004. The winds at the Chesapeake Bay Bridge 

Tunnel (CBBT) were five m/s from the SW (Figure 59). The winds died down 

early in the study period and changed to easterly, but then slowly increased in 

speed and rotated to southwesterly. 

Figure 57. Old Dominion University’s research vessel the

R/V Fay Slover 
55

Figure 58. Calibrating the compass of the ATON current measurement system on 

LB 2CH 

Figure 59. Wind speed, direction, and gust during the experiment observed at the 

Chesapeake Bay Bridge Tunnel NOS station 
56

Study Results. Data from the 24-hour survey are presented here. Generally, 

there is agreement between the current measurements from the two systems. The 

major shifts in current direction (flood to ebb) are observed in both data sets, as 

well as the relative differences in the strength of flood and ebb (Figures 60-62). 

Agreement is best in the near-bottom bins, particularly in the east/west component 

of the current. In other intercomparisons performed by CO-OPS (one in the 

Potomac River and one in the Gulf of Mexico), the agreement decreased at times 

when the current was changing direction (i.e. when the currents were weak and 

variable). These data do not show this pattern—the timing of the change from the 

southeast to the northwest is nearly simultaneous in the bottom-mounted and 

ATON record, with the slight exception of some phase difference in the nearsurface (bin one).

Figure 60. Near surface eastward and northward current velocities observed by the hull-mounted 

ADCP (black) compared to those observed by ATON-mounted system (red) 
57

Figure 61. Mid-depth eastward and northward current velocities observed y the hull-mounted 

ADCP (black) compared to those observed by ATON-mounted system (red) 

Figure 62. Near-bottom eastward and northward current velocities observed by the hullmounted ADCP (black) compared to those observed by ATON-mounted system (red) 
58

Focusing first on the observed current speed, CO-OPS found that the mean speed 

difference for the top usable bin (2.62 m) was 10.7 cm/s with an s.d. of 7.3 cm/s 

(Figure 63). The agreement increases with depth, with the bottom bin showing the 

least difference between the ship and ATON (Figure 64). The speed differences are 

considerably higher than those observed in other CO-OPS intercomparisons. 

During both the Freeport, Texas and Potomac River comparisons the mean speed 

differences (and s.d. about those means) were only 3 cm/s at all depths. CO-OPS 

investigated possible explanations for these higher speed differences. Sample size 

is an important factor. Here only one day of data is compared, while during the 

Freeport and Potomac experiments, the data sets were 60 and 30 days respectively. 

The ATON-mounted pitch and roll values are of the same order of magnitude as the 

Freeport and Potomac River comparisons (Figure 65). 

Figure 63. Near surface current speed observed by the hull-mounted ADCP (black) 

compared to that observed by ATON-mounted system (red). The difference is shown in green. 

A very large vertical velocity is observed in this top bin. 
59

Figure 64. Depth relationship of the speed difference between ship- and ATONmounted current measurements 

Figure 65. Pitch and roll from both current measurement systems
60

As with previous studies, CO-OPS was most concerned about the agreement 

between the current direction measured. The general current patterns were 

observed by both measurement systems. For the 3.5 m bin, the mean of the 

absolute value of the difference in six-minute directions is 27.8° (s.d. = 33.9°) 

(Figure 66). The agreement was slightly better in the near-bottom bin, with the 

mean of the absolute value of the difference in six-minute directions of 20.6° 

(s.d. = 18.7° [Figure 67]). The sample-to-sample differences in direction are not 

all uniform with depth, and are particularly noisy when the current is reversing 

(Figure 68). 

Figure 66. Direction measured by the ship and ATON current profilers and the absolute 

value of the difference 
61

Figure 67. Time-series of current direction and current direction difference, 

Buoy 2CH comparison, May 2004 

Figure 68. Time-series of current direction difference over depth, Buoy 2CH 

comparison, May 2004 
62
63

4.0 FIELD PROCEDURES

 4.1 Pre-Deployment ATON Reconnaissance 

As with any measurement system installation, a detailed reconnaissance of the 

particular ATON and at the shoreside station location is essential. 

 4.1.1 Safety Precautions 

NOAA and CO-OPS safety procedures require life vests to be worn by all persons 

at all times while on a vessel of any size. Closed-toe shoes are also required. The 

following is an excerpt from the CO-OPS Field Facility Safety Rules – 4/7/04 

draft which applies to ATON current profiler work. These safety rules 

supplement the NOAA Safety Rules Manual (4/1/03 draft). Risk of injury or loss 

of life is not to be compromised for data or equipment. 

• Installation and recovery of an ATON ADCP have potentially two 

major safety hazards: being struck by heavy equipment and falling 

in the water. 

• Weather awareness shall be priority; buoy work should not be 

conducted at winds higher than 15 knots and seas greater than two 

feet. The crew’s discretion shall be used at all times to determine 

safe conditions. 

• Hard hats shall be available on the boat and shall be worn when 

lifting the instrument on or off the boat. 

• Personal Flotation Devices (PFD) shall be worn by all personnel 

on a boat. 

• Lines should be inspected to ensure good condition. 

• An installation/recovery shall have a minimum of four employees. 

 4.1.2 Establish Local Contact

The CO-OPS PORTS® Site Representative or the PORTS® Implementation 

Manager will establish a Points of Contact (POC) list for each ATON current 

station and associated shore station. 
64

 4.1.3 Will the Clamparatus fit?

Although 8' x 26' ATONs are a USCG standard, there is slight variability in the 

size of each buoy. The most important factor is whether or not there is enough 

space behind one of the lifting eyes to accommodate the electronics box and red 

ring. CO-OPS has encountered one 8' x 26' ATON that did not have enough flat 

deck space around an eye to secure the clamparatus. In this case CO-OPS had to 

move the whole station to an ATON nearby. A site visit should be performed 

prior to initial deployment on each ATON and after the ATON has been rotated 

out for service. 

 4.1.4 Can the signal be received at the shore station? 

Prior to the installation of a shoreside station at a specific location, it must be 

determined whether or not a signal transmitted from the buoy mounted system can 

be received reliably at that location. 

The first step in determining the viability of a site is to perform a visual inspection 

of the area. There should be a clear line of sight between the antenna on the shore 

station and the buoy. The site should be able to support a mast of appropriate 

height for the distance between the shore station and the buoy. (See section 4.3.2) 

The radio frequency spectrum that is being used should also be checked to see if 

there are any possible sources of interference in the area where the shore station is 

located or in the path between the shore station and the buoy. This can be done 

using a spectrum analyzer, an omni-directional antenna, and a yagi antenna. 

4.2 Deployment Preparation 

 4.2.1 Assembly Steps 

The Field Guide to ATON Current Measurement Systems (currently being 

drafted) contains details of the clamparatus assembly. 
65

 4.2.2 Electronics Diagrams 

The shoreside station consists of a DCP, communication equipment, and batteries. 

The DCP is the 9210 model manufactured by Sutron Corporation and is part of 

the Xpert family of DCPs. 

Figure 69. 9210 ADCP shoreside unit with telephone modem 
66

Figure 70. 9210 ADCP shoreside unit with CDMA IP modem 
67

 4.2.3 Bench Testing 

The following bench testing procedures should be conducted on a complete buoy 

mount system with an ADCP. 

 4.2.3.1 Bench test with AquaPro 

1. Connect a computer directly to the shoreside radio. 

2. Initialize the AquaPro program provided by Nortek. 

3. Under the Communications tab select Serial Port. 

4. Set the Serial port: field to the com port that the radio is connected to on the 

 computer. 

5. Set the Baud Rate: field to 2400. 

6. Set the Recorder/Configuration baud rate: field to 2400. 

7. Uncheck the Hard Break check box. 

8. Left click the OK button (Figure 71). 

9. Press the Stop Data Collection button to initiate the serial port settings. 

(Figure 72). 

Figure 71. Screen shot of Aquapro bench test configuration 
68

10. Under the Deployment tab select Planning and Load from Instrument 

(Figure 73.) 

Figure 73. Screen shot of Load from Instrument setting 

Figure 72. Screen shot of Stop Data Collection to initiate serial port settings 
69

11. Enter the Deployment Planning settings as in the following figures and left click 

the OK button. 

Figure 74. Screen shot from Deployment Planning settings – Standard Tab 

Figure 75. Screen shot from Deployment Planning settings – Advanced Tab 
70

12. Under the Online tab select Disk Filename and enter an appropriate file name in 

 the Base Name and Folder: field. 

13. Left click on the OK button. 

14. Under the Online tab select Start Disk Recording and then select Start Data

Collection. See Figures 76-77. 

Figure 76. Screen shot from Start Data Collection Disk Files

Figure 77. Screen shot from online 
71

15. Allow the ADCP to collect data and observe these data. With the Deployment 

Planning settings used in this test procedure, data will be available in the cell fields after 

300 seconds. Data will be available in the other fields and graphs after 360 seconds. 

 4.2.3.2 Bench test with a 9210 

1. Connect COM2 of the 9210 directly to the MaxStream radio and power on the 

 9210. 

2. Connect a computer to COM1 of the 9210 and initialize XTerm. Check to see 

 that recording is ON. 

3. After 12-15 minutes have passed, transfer the current MMDDYYYY.dat file and 

the Recent.dat file to your computer using the File Transfer button on XTerm. 

(Figures 78-79). 

Figure 78. Screen shot of file transfer selecting files to be transferred to PC 
72

4. Open the Recent.dat and MMDDYYYY.dat files and check to see that valid data 

were entered for the last reading. Table 1 is an example of valid data set retrieved 

from a bench test. 

Table 1. Valid data set retrieved from a bench test 

********************************************************************** 

09 20 2004 14 59 44 00000000 00101100 12.2 1528.1 111.1 56.6 59.8 0.666 23.25 0 15281 

0.916 -0.159 0.464 25.0 24.0 26.0 

0.426 0.036 -0.449 24.0 24.0 26.0 

0.850 -0.270 -0.257 24.0 24.0 26.0 

0.069 0.362 -0.427 24.0 24.0 26.0 

0.162 0.412 0.060 24.0 24.0 26.0 

0.551 -0.021 -0.192 24.0 24.0 26.0 

0.812 0.019 -0.124 24.0 24.0 26.0 

0.756 0.265 -0.472 24.0 24.0 26.0 

0.657 0.077 0.396 24.0 24.0 26.0 

0.420 0.074 0.234 24.0 24.0 26.0 

0.643 -0.096 -0.154 24.0 24.0 26.0 

1.133 -0.446 0.143 24.0 24.0 26.0 

0.647 0.065 -0.432 24.0 24.0 26.0 

0.341 -0.100 -0.458 24.0 24.0 26.0 

0.602 0.132 -0.225 24.0 24.0 26.0 

0.640 0.183 -0.414 24.0 24.0 26.0 

0.336 -0.233 -0.236 24.0 24.0 26.0 

0.637 0.021 -0.433 24.0 24.0 26.0 

1.053 -0.365 0.795 24.0 24.0 26.0 

1.082 -0.529 -0.504 24.0 24.0 26.0

Figure 79. Screen shot of completed file transfer 
73

5. Allow system to run for 24 hours. Inspect the MMDDYYYY.dat files at the end 

of this time period for zero fill entries. Also inspect the BadData.dat and 

BadTime.dat files if necessary. 
74

On Boat 

3⁄4 Clamparatus with bridle attached (take off clamp block and hardware) 

3⁄4 Life vests 

3⁄4 “Throne” (wooden platform for laptop during calibration spin) 

3⁄4 Line for calibration spin 

3⁄4 “Hoistaratus” (block and tackle used to lift system) 

Blue Bag #1 - Install 

3⁄4 Gloves 

3⁄4 Wire snips 

3⁄4 Cable ties 

3⁄4 1⁄2-inch ratchet and open wrench 

3⁄4 Antenna mount / 2 U-bolts & hardware 

3⁄4 Clamp block/ bolts & hardware 

3⁄4 1 1⁄8-inch ratchet and open wrench 

3⁄4 Large crescent wrench 

3⁄4 Anti-theft Allen screwdriver 

3⁄4 Never Seize 

3⁄4 Marine caulk 

Blue Bag #2 - Calibration/Radio 

3⁄4 Laptop w/ AquaPro 

3⁄4 Calibration directions 

3⁄4 Deployment/Recovery Logs 

3⁄4 12-volt battery 

3⁄4 Test cable 

3⁄4 Dummy plug 

3⁄4 Shore radio and power supply 

3⁄4 Serial cable 

3⁄4 Power inverter 

3⁄4 Vulcanizing tape 

3⁄4 Electrical tape 

3⁄4 Knife 

4.2.4 ATON Current Profiler Deployment Packing List

Prior to installation/maintenance visits, personnel must ensure that the following 

items are in each of the three ATON bags (Black Duffle, Install, and Calibration). A 

hard copy of the following text is in a plastic sleeve inside the blue tool bag marked 

ATON CAL. Personnel are encouraged to print a spare and place it somewhere else in 

their field gear. 

Black Duffle 

3⁄4 First aid kit 

3⁄4 Rags 

3⁄4 Handi-wipes 

3⁄4 Plug grease 

3⁄4 Camera 

3⁄4 Aquadopp Manual 

3⁄4 PORTS® brochures & cards 

3⁄4 Spares (in black zippered pouch) 

3⁄4 Wire snips 

3⁄4 Cable ties 

3⁄4 1⁄2-inch ratchet and open wrench 

3⁄4 Antenna mount /2 U-bolts & hardware 

3⁄4 Clamp block/ bolts & hardware 

3⁄4 1 1⁄8-inch ratchet and open wrench 
75

4.3 Initial Installation 

 4.3.1 ATON Installation 

 4.3.1.1 Notify Local Contact 

The CO-OPS PORTS® Site Representative or the PORTS® Implementation Manager 

will supply the field crew with a POC list for each ATON current station and 

associated shore stations. The Field Crew Chief should notify the appropriate local 

contact several days in advance of the installation. If the ATON is located near a 

busy navigation channel, the local pilot dispatcher should be notified as a precaution. 

 4.3.1.2 Safety Precautions 

See Section 4.1.1. 

 4.3.1.3 Securing the Clamparatus 

CO-OPS designed and assembled a block and tackle for lifting the clamparatus from 

the boat onto the ATON. This system of rope, pulleys, and clips is nicknamed the 

“hoistaratus”. The following outlines the steps to be taken to secure the clamparatus. 

1. One crew member transfers to the ATON and ties down the bell clappers for 

noise comfort and safety so the clappers don’t pinch anyone. 

2. The same or different crew member then carries the hoistaratus to the top of 

the ATON superstructure and secures it to the cage frame (Figure 40). 

3. The three clips are then secured to the eyes in the top ring of the 

clamparatus. 

4. The transfer operation requires two people on the ATON and two people on 

the boat. One person on the ATON pulls on the lifting line as the two people 

on the boat guide the clamparatus up and over the bulkhead, taking special 

care to protect the sensor’s acoustic transducers at the end of the tube. 

5. One crew member releases the hoistaratus, once the clamparatus has been 

lowered over the ATON lifting bail. 

6. The two crew members on the ATON then place and secure the clamp block. 

7. One crew member then climbs to the top of the ATON, removes the 

hoistaratus and installs the radio antenna. The antenna cable is secured with 

tie wraps all the way down the ATON’s superstructure. 

8. At this point the crew member who is running the calibration software 

should board the ATON. 
76

 4.3.1.4 Calibrating a Nortek Compass on an ATON 

The ATON’s steel hull has a significant magnetic effect on the Nortek compass. 

Because of this effect, a compass calibration must be run each time a Nortek is 

installed or swapped out. The calibration is performed by running Nortek’s Aquapro 

software and rotating the buoy slowly at least three rotations of 360° each. The 

spinning is most easily accomplished by tying one end of a polypropylene line to the 

buoy’s lifting eye and handing off the line to the boat. The boat then circles the 

ATON three times and prepares to “pull the cord”. A hard copy of the following text 

is in a plastic sleeve inside the blue tool bag marked ATON CAL. Personnel are 

encouraged to print a spare and place somewhere else in their field gear. 

The procedure detail is outlined on the following pages. 
77

ATON Calibration Procedure 

1. Connect to instrument: 

• Unplug sensor cable from electronics box and plug into the test cable 

• Put dummy plug on bulkhead connector 

• Plug other end of test cable into serial port on laptop computer and 

power into battery 

2. Power up and log onto laptop computer 

3. Start Aquapro 

4. Increase baud rates to maximum: Communications > Serial Port (no hard break) 

5. Calibrate Compass:

• Press Online > Compass Calibration 

• Notify the boat that you are ready and push start when spinning starts 

• Push STOP when buoy stops spinning or just before (better than after) 

• Select Update Instrument if it was a quality calibration 

• Select NO if the trace was not three complete revolutions, you think it 

went too fast, or there was a stop in the spinning 

 ■ If you elected not to update the instrument repeat Step 5 

 ■ When satisfied select Update Instrument

6. Save Calibration Data:

 In order to export results of the calibration to buoyXXX_cal.dat: 

• Right-click on the data plot 

• Export > Text/Data Only > File > Browse and select folder and 

filename 

• Export > Data > Table >point/subsets 

• Export 

7. Check laptop computer for files 

8. Reset baud rates to 2400: 

• Communications > Serial Port (no hard break) - Baud Rate and 

Recorder/Configuration Baud Rate 

9. Start Instrument Sampling:

• Set up file on laptop to record a few samples 

• Online > Disk Filename (name it XXX_buoy_aftercalib) 
78

10. Check clock: 

• Online > Set Clock (make sure time is GMT)

11. Check settings: 

• Deployment Planning > Download From Instrument 

• Uncheck use advanced, check all standard settings: 

■ Moving buoy 

■ Profile interval 360 seconds 

■ Compass update one second 

■ 20 one-meter cells 

• Click Apply 

• Then check Use Advanced, check advanced settings: 

■ Average interval 300 seconds 

■ Compass update one second 

■ Turn on File Wrapping 

• Click Apply 

• Click OK 

12. Start Recorder Data Collection

13. Start Disk Recording

14. Collect two six-minute samples

15. Quit Aquapro SAY NO to turn off recorder 

16. Reattach sensor cable to box and screw tight the connector’s sleeve 

17. Return to boat and relax!! 
79

 4.3.2 Shore Station Installation 

 4.3.2.1 Data Collection Platform 

See Section 2.4.1. 

 4.3.2.2 Power / surge protection 

The 9210 and the RF radio run off of a 12V 38AHh battery which is charged by a 30 

W solar panel through a 12V, 8ah solid state PV charge controller. The Raven 

CDMA runs off of a 12V 38AHh battery which is charged by a 30 W solar panel 

through a 12V, 8ah solid state PV charge controller. The radio and IP antennas are 

connected to their respective devices through Polyphaser 125-1000 MHz impulse 

suppressors (lightning protection system) which are connected to earth ground. These 

suppressors are capable of 50,000ah IEC 61000-4-5 8/20 μs waveform surges. 

 4.3.2.3 Communications 

See Section 2.4.2 . 

An estimate of the antenna height required for a specific shore station can be 

determined using the equation. 

r ≈ 43.3 x √(d/(4f)) 

Where r is the antenna height in feet, d is the distance between the shoreside station 

and the buoy in miles, and f is the frequency in GHz. The value of f should be the 

lowest frequency in the spectrum being used. 

 4.3.3 Nortek Settings 

CO-OPS has experimented with various Nortek configurations in order to balance 

data quality (requiring more pinging) and power consumption (less pinging). Table 

2 contains the standard configuration currently being used. 
80

Table 2. Standard Nortek Configuration Settings 

***************************************************************** 

Configuration file buoy.prf has been created, based on this instrument: 

Instrument serial no: AQD 1252 

Transducer serial no: AQP 1052 

Firmware version: 1.11 

Frequency: 1000000 Hz 

Instrument configuration: 

Cell size: 1.00 m 

XmitLength: 1.00 m 

Number of cells: 20 

Blanking: 0.41 m 

Coordinate system: ENU 

Measurement interval: 360 s 

Averaging interval: 300 s 

Pings per s: 1 

Compass update rate: 1 s 

AquaPro software version (that created config): 1.23 

Note: this configuration file must be used only with a 1 MHz profiler.

***************************************************************** 

 4.3.4 Verifying Data Flow 

1. Connect a computer to COM1 of the 9210 and initialize XTerm. 

2. Check to see that recording is ON. 

3. From 12-15 minutes after initiating the recording on the 9210, transfer the 

 current MMDDYYYY.dat file and the Recent.dat file to your computer 

 using the File Transfer button on XTerm (Figures 78-79). 

4. Open the Recent.dat and MMDDYYYY.dat files and check to see that valid 

 data were entered for the last reading. Table 1 provides a valid data set 

 retrieved from a bench test. 

 

5. Allow the system to run for one hour. 

6. Inspect the MMDDYYYY.dat files at the end of this time for zero fill entries. 

Zero fill entries indicate an unstable radio link or a source of interference. 

7. Also inspect the BadData.dat and BadTime.dat files if necessary. 
81

4.4 Preventative Maintenance and Repair Visits 

 4.4.1 Notify Local Contact 

The CO-OPS PORTS® Site Representative or the PORTS® Implementation Manager 

supplies the field crew with a POC list for each ATON current station and associated 

shore stations. The Field Crew Chief notifies the appropriate local contact several 

days in advance of the maintenance visit. If the ATON is located near a busy 

navigation channel the local pilot dispatcher should be notified as a precaution. 

4.4.2 Call CORMS 

As with any PORTS® maintenance or repair visit, the CORMS watch stander must be 

notified prior to starting any work on the shore station or on the ATON itself, and 

again upon completion of the job. The procedure is as follows: 

• Call 301-713-2540 

• Identify yourself and the station to be worked on 

• Give a general description of the procedure 

• Provide an expected time to return the station to operational 

 4.4.3 Safety Precautions 

See Section 4.1.1. 

 4.4.4 Maintenance Checklist 

• Inspect the enclosure for any visible signs of damage. Inspect the weather 

seal on the enclosure and any cable feed-throughs for damage. 

• Visually inspect the mast for damaged or off-axis solar panels, GOES 

antennas, and radio antennas. Re-adjust or replace as necessary. 

• Copy the daily data files off the storage card and delete all daily files except 

for the most current one. 

• Check desiccant tabs and packs and replace if necessary. 

• Check battery voltage levels. If below 11.5V direct current (DC), change 

battery. 

• Check voltage entering the voltage regulators from the solar panels and the 

voltage exiting the voltage regulators. Voltage exiting the regulators should 

be approximately 13.5VDC, and voltage entering the regulators should be 
82

approximately 18VDC on a sunny day. 

 4.4.5 Deployment and Recovery Logs 

For each deployment and recovery of a current profiler, a log sheet must be filed with 

the Product and Services Division’s (PSD’s) CECAT team. The log includes date, 

time, crew, instrument information, location, and weather. A hard copy of the log 

sheet is in a plastic sleeve inside the blue tool bag marked ATON CAL. Personnel are 

encouraged to print a spare and place it somewhere else in their field gear. 
83

 

 

ATON CURRENTS DEPLOYMENT LOG 

GENERAL INFORMATION

PORTS:_______________________ Date & Time (UTC):_______________________ 

Station ID:_____________________ Field Party: ______________________________ 

Station Name: __________________ Captain: _________________________________ 

Vessel: _______________________ Crew: ___________________________________ 

AQP SETUP INFORMATION 

ADP Platform:______________________ USCG ATON (Light List No):_______________ 

AQP Make:_________________________ AQP Probe SN:________ AQD SN:__________ 

Frequency:_________________ Bin length:___________ # bins:________________ 

Blanking Dist:______________ Averaging Interval:_____ Sampling Int.:__________ 

Start Time:_________________ Config. File:__________ Calibration File:________ 

Data Types:________________ Offset to UTC:_________ Recorder size:__________ 

LOCATION INFORMATION

Position:_________________________________ NOS Chart No.:_____________________ 

Local Magnetic Variation:___________________ Station Depth and Source:_____________ 

Sensor Depth (m):_________________________ Location/Bearings:___________________ 

ENVIRONMENT

Water Level Station Name:_____________________ Water Level Station No.: ___________ 

Wave Height:_____________ Water Temp:__________ Air temp:_____________ 

Wind Speed:______________ Wind Dir.:____________ Weather Obs:__________ 
84

ATON CURRENTS RECOVERY LOG 

 

GENERAL INFORMATION

PORTS:_______________________ Date:____________________________________ 

Station ID:_____________________ Field Party: ______________________________ 

Station Name: __________________ Captain: _________________________________ 

Vessel: _______________________ Crew: ___________________________________ 

LOCATION INFORMATION

Position:_________________________________ NOS Chart No.:_____________________ 

Local Magnetic Variation:___________________ Station Depth and Source:_____________ 

Sensor Depth (m):_________________________ Location/Bearings:___________________ 

ENVIRONMENT

Water Level Station Name:_____________________ Water Level Station No.: _____________ 

Wave Height:_____________ Water Temp:__________ Air temp:_______________ 

Wind Speed:______________ Wind Dir.:____________ Weather Obs:____________ 

RECOVERY INFORMATION 

Reason for visit:________________________________________________________________ 

Time on Deck or Time of Download:_______________________________________________ 

AQP DATA RETRIEVAL INFORMATION 

ATON Description:__________________ USCG Buoy (Light List No): ________________ 

AQP Make:_____________ AQD SN:___________ AQP Probe SN: ___________________ 

Frequency: ____________ Data Types: ________ Time of download:_________________ 

File name:______________ File size:____________ FTP Location:_____________________ 
85

4.4.6 Downloading Data from a Nortek on an ATON 

The Nortek profiler can store data on an internal recorder, as well as send data out 

over the serial port in real-time. This capability should always be enabled so that 

small gaps in communications do not cause gaps in the current data available for 

comparisons, predictions, and other historical/retrospective data products. The data 

on the profiler’s memory card should always be downloaded before removing the 

clamparatus during maintenance visits. 

The following procedure describes how to download data from the instrument and 

then resume operation. A hard copy of the following text, Downloading Data, is in a 

plastic sleeve inside the blue tool bag marked ATON CAL. Personnel are encouraged 

to print a spare and place it somewhere else in their field gear.
86

Downloading Data 

1. Connect to instrument: 

• Unplug sensor cable from electronics box and plug into the test cable 

• Put dummy plug on bulkhead connector 

• Plug other end of test cable into serial port on laptop computer and 

power into battery 

2. Power up laptop computer 

3. Start Aquapro 

4. Increase baud rates to maximum: Communications > Serial Port (no hard break) 

5. Retrieve Data:

• Select Recorder Data Retrieval icon - select files - save to desktop 

•Repeat as necessary to get all data 

•Close Data Retrieval dialog box 

6. Check desktop for files and file size 

7. Reset baud rates to 2400: 

Communications > Serial Port (no hard break) - Baud Rate and 

Recorder/Configuration Baud Rate 

8. Start Instrument Sampling:

• Set up file on laptop to record a few samples: 

• Online > Disk Filename (name it XXX_buoy_aftercalib) 

9. Check clock: 

• Online > Set Clock (make sure time is GMT)

11. Check settings: 

• Deployment Planning > Download From Instrument 

• Uncheck use advanced, check all standard settings: 

■ Moving buoy 

■ Profile interval 360 seconds 

■ Compass update one second 

■ 20 one-meter cells 

• Click Apply 

• Then check Use Advanced, check advanced settings: 
87

■ Average interval 300 seconds 

■ Compass update one second 

■ Turn on File Wrapping 

• Click Apply 

• Click OK 

12. Start Recorder Data Collection

13. Start Disk Recording

14. Collect two six-minute samples

15. Quit Aquapro SAY NO to turn off recorder 

18. Reattach sensor cable to box and screw tight the connector’s sleeve 

Return to boat and relax!!
88

 4.4.7 Downloading Data from the Shore Station DCP 

Data can be retrieved from the DCP in two forms, either as Recent.dat file or the daily 

files. 

 4.4.7.1 Recent.dat 

The Recent.dat file is mainly used when the system is being polled. This file 

provides the most recent data set. The Xpert operating system allows the user to 

create a custom login, which provides the Recent.dat file when prompted with that 

login. 

 4.4.7.2 Daily Files 

The daily files are in the form MMDDYYYY.dat. These files contain all the data sets 

from that day. These files can be retrieved by logging into the 9210 under a Setup

login. Open the file transfer screen by pressing the File Transfer button. Highlight 

the appropriate daily files and press the “<==” button to transfer the files to the 

connected computer (Figure 80). 

Figure 80. Screen shot of file transfer to connected computer 
89

 4.4.8 Nortek Settings 

See Section 4.3.3 

 4.4.9 Verifying Data Flow 

See Section 4.3.4.
90
91

5.0 DATA FLOW

 5.1 From the ATON to Shore 

The clamparatus electronics box contains a MaxStream spread-spectrum radio, which 

transmits the current data to the shore station every six minutes. The Sutron DCP is 

connected to the receiving MaxStream radio modem at the shore station. Once the 

DCP is at full power, it performs a number of self-tests on its internal systems; any 

errors are displayed on the front panel LCD and recorded in the system logs. After 

the self-tests, the system reads the setup file and initiates the AquaPro.sll, the 

software that performs the following: 

• Sets the recording options (daily, weekly recent, and/or time sync) 

• Checks COM ports and baud rates 

• Wakes up the MaxStream radio on the buoy 

• Establishes communications with the profiler

• Stops the profiler 

• Sets the profiler time and date 

• Sets the profiler parameters (settings are taken from the buoy.cfg file on DCP) 

• Starts the profiler 

• Establishes the following files on the DCP storage card 

 ■ MMDDYYYYHHMMSS.hrd — ASCII text file based on the 

 Buoy.cfg file that lists the profiler’s parameters 

 ■ MMDDYYYYHHMMSS.cfg—a copy of the Buoy.cfg file 

 ■ MMDDYYYYHHMMSS.prf—raw profiler data 

• Starts polling the radio serial port every three seconds 

Every six minutes the profiler sends the raw data to the DCP. When the DCP 

receives the data the following actions are taken: 

The received message length is compared to the expected message length. 

If the message is complete: 

• Copies the raw message to the MMDDYYYYHHMMSS.prf file 

• Converts the raw message to ASCII 

• Places a copy of the raw ASCII data in the Recent.dat file 

• Appends the MMDDYYYY.dat or weekly.dat file with the raw ASCII data 

If the message is not complete: 

• Appends the raw message to the BadData.dat file. 

• Writes the time the data was received, the message length, and an error flag to 

the BadTime.dat file 
92

If a message is not received within a given time frame 

• Takes the time and date from the DCP, writes an ASCII file with that time and 

date, and copies it to the Recent.dat file. 

• Sets all data fields in the file to zero. 

• Writes the file to the MMDDYYYY.dat 

 5.2 To the Data Acquisition System (DAS) 

The data flow for the Nortek profiler is consistent with other types of current meters 

used in CO-OPS, with one exception. With other current profilers the DAS directly 

polls the instrumentation, but with the Nortek the DAS polls an Xpert DCP. The 

DCP collects data from the Nortek and creates a data file for the DAS. 

The DAS collects data from the DCP every six minutes. Data collection is controlled 

by a LINUX “cron” process. The “cron” process starts a data collection script, which 

uses kermit to retrieve the data from the DCP. The DAS acquires the data from the 

DCP by using various communication methods. With a connection to the DCP, the 

DAS enters a special login, which triggers the DCP to output the last data sample 

collected from current profiler. The DCP outputs the data in a pre-determined format 

file called recent.dat (example in Table 3):

Table 3. Example of a “recent.dat” format file 

********************************************************************************************************* 

Login user: a 

 Password: 

Recent.Dat 

09 27 2004 13 54 52 00000000 00110001 11.9 1520.1 115.1 -3.5 4.3 2.701 20.58 0 15201 

 -0.488 -0.258 -0.116 103.0 195.0 106.0 

 -0.299 -0.173 -0.035 100.0 153.0 115.0 

 -0.181 -0.077 0.032 96.0 71.0 113.0 

 -0.305 -0.059 0.107 106.0 58.0 115.0 

 -0.394 -0.022 0.124 107.0 61.0 112.0 

 -0.433 -0.217 0.121 105.0 59.0 102.0 

 -0.530 -0.248 0.123 103.0 52.0 90.0 

 -0.529 -0.318 0.085 89.0 47.0 80.0 

 -0.428 -0.392 -0.002 69.0 42.0 70.0 

 -0.379 -0.306 -0.027 69.0 39.0 68.0 

 -0.373 -0.334 -0.034 79.0 43.0 79.0 

 -0.264 -0.343 -0.021 97.0 53.0 93.0 

 -0.087 -0.102 -0.022 136.0 88.0 131.0 

 -0.008 -0.047 -0.021 106.0 112.0 127.0 

 0.030 -0.065 -0.021 31.0 52.0 51.0 

 -0.187 0.007 0.064 21.0 25.0 24.0 

 -0.159 -0.035 0.022 20.0 22.0 21.0 

 -0.079 -0.080 0.127 20.0 21.0 21.0 

 0.102 -0.223 0.009 21.0 20.0 20.0 

 -0.113 0.075 0.167 20.0 20.0 20.0 

End Recent.dat 

********************************************************************************** 
93

After the DAS has acquired the current data, it begins a series of steps to produce 

quality control (QC) flags that indicate the quality of the data. A Criteria Table is 

used to implement QC checks. The table contains a set of high and low ranges, 

against which the data collected are compared. This table and the actions that result 

from the flag generation are described in Section 6.0 (Quality Control). 

The result of the processing and data checking is that the DAS produces a PUFFF 

(PORTS® Uniform Flat File Format) file, a PORTS® standard data product, which is 

used to share PORTS® data with our users. A detailed description of the PUFFF 

documentation is available at http://co-ops.nos.noaa.gov/publications/pufff4.pdf. Table 4 

contains an example of an ATON PUFFF.

Table 4. ATON PUFFF ***************************************************************************************************************8***

**********Chesapeake Bay PORTS 

cb1101 LBB "92" 

 1142 -42 18 2056 271 0 0 0 0 0 15201 0 0 

 2004 09 27 13 54 20 00000000000000000000000000001000 401 FCSC 

 1 -396 -270 -53 236 479 49 84 50 0 0 0 2056 

00000000000000000000000000000000 

 2 -311 -230 -3 233 387 45 65 49 0 0 0 2056 

00000000000000000000000000000000 

 3 -330 -118 54 250 351 44 32 48 0 0 0 2056 

00000000000000000000000000000000 

 4 -354 -111 132 253 371 46 28 49 0 0 0 2056 

00000001100000000000000000000000 

 5 -414 -111 146 255 429 46 29 48 0 0 0 2056 

00000000000000000000000000000000 

 6 -385 -231 150 239 449 43 28 43 0 0 0 2056 

00000000000000000000000000000000 

 7 -441 -320 132 234 545 41 26 37 0 0 0 2056 

00000000000000000000000000000000 

 8 -449 -371 75 230 583 36 22 33 0 0 0 2056 

00000000000000000000000000000000 

 9 -348 -307 40 229 464 31 19 32 0 0 0 2056 

00000000000000000000000000000000 

 10 -243 -316 7 218 398 29 18 30 0 0 0 2056 

00000000000000000000000000000000 

 11 -299 -323 -5 223 440 31 18 31 0 0 0 2056 

00000000000000000000000000000000 

 12 -246 -312 -7 218 397 41 22 40 0 0 0 2056 

00000000000000000000000000000000 

 13 -26 -97 -14 195 101 58 38 56 0 0 0 2056 

00000000000000000000000000000000 

 14 59 0 -24 90 59 43 49 54 0 0 0 2056 

00000000000000000000000000000000 

 15 -45 64 21 325 79 13 23 22 0 0 0 2056 

00000000000000000000000000000000 

 16 31 -38 -11 141 49 9 11 10 0 0 0 2056 

00000000000000000000000000000000 

 17 0 253 74 0 253 9 9 9 0 0 0 2056 

00000000000000000000000000000000 

 18 78 277 148 16 288 9 9 9 0 0 0 2056 

00000000000000000000000000000000 

 19 158 91 65 60 182 9 9 9 0 0 0 2056 

00000000000000000000000000000000 

 20 -122 -538 118 193 552 9 9 9 0 0 0 2056 

00000000000000000000000000000000 

 0 0 3 0 0 1 2 1 0 

 0 0 0 49 0 0 0 0 0 0 

 0 0 0 0 0 0 0 60 2709 

CORMS 01000000000000000000000000000000 01010000000000000000000000000000 

*************************************************************************** 
94

 5.3 Data Flow to CORMS and to Products 

The DAS then begins the process of sending data back to Silver Spring for CORMS 

and ingestion into the CO-OPS databases. The data are transferred from the DAS to 

TESTPORT, a server in Silver Spring, which adds no value to the data but acts as a 

traffic cop by transferring data to the appropriate servers throughout CO-OPS. 

TESTPORT distributes the current data along with all the other data types collected 

as PUFFF files to a number of CO-OPS servers that are involved in the ingestion 

process (Figure 81). The Data Ingestion Server (DIS) acquires, processes, generates 

QC flags and loads the data into the NPDB (CO-OPS databases). The CORMS 

server provides an interface for the CORMS operators to see the flags that are 

generated at the DAS. It allows the operators to stop and start dissemination of 

sensor data. The users then access the data using the various interfaces and products 

that CO-OPS has developed. 

It is important to note that ATON current profiler data follow the same path as other 

CO-OPS data types. 
95

Figure 81. CO-OPS ATON Data Ingestion Process

Figure 82. Diagram of the Chesapeake Bay PORTS® data collection system
96
97

6.0 QUALITY CONTROL

Dissemination of data of a known quality in an operational real-time environment is a 

priority for CO-OPS, thus QC is performed at two possible locations during the 

ingestion process. QC is conducted either when data are collected at the DAS or 

when the data arrive at the DIS via GOES transmission. The same QC criteria are 

used at each of the ingestion sites. Data quality is evaluated by the CORMS 

Operators who have plotting tools to visually inspect the data using the CORMS 

Interface. 

The DAS provides point-to-point QC as data are collected. The following checks are 

performed on the data to generate QC flags. The types of QC checks that are flagged 

are: 

• Time Check 

The time associated with each data sample is compared to the DAS system 

clock, which is synchronized daily with the Naval Observatory clock. The 

DAS uses a time range from 18 minutes into the past to two minutes into the 

future. If the time of the data is outside this range, then the DAS flags these 

data as bad. The data are saved to a log file on the DAS. This log provides a 

troubleshooting history. The time check was implemented to handle clock 

drifting issues that occur in all types of sensors and to check for setup errors 

associated with time zone changes (i.e., GMT versus standard or local time). 

• Absolute Range 

The values for speed, pitch, roll, heading, water temperature, pressure, and 

echo amplitude must fall between a pre-determined lower and upper limit (see 

Table 6). If any value is greater than the upper limit or less than the lower 

limit, the DAS sets a warning flag for the data. The range limits for each of 

the parameters at each station may be adjusted after 30 days of good data are 

acquired. 

• Rate of Change 

Rate of change values listed as “delta warn” in the criteria file are not 

implemented at the DAS level at this time. The rate of change flags will be 

implemented in the future. 

• Real-Time Bin 

The real time bin is the depth area in the water column chosen to be reported 

in real-time for dissemination to the public. The real-time bin is defined in the 

station control file (Table 6) along with a valid lower limit. If there are any 

QC flag warnings or failures at the real time bin, the next lower bin is used 

until the lower limit is reached. Data below the lower limit are saved to a file, 

but not disseminated. 
98

Table 5 provides an example of a Criteria File. 

Table 5. Sample Criteria File 

*************************** Sample Criteria File ********************************* 

#lowest below this value is an error 

#highest above this value is an error 

# 

#lowest highest 

#error error 

 0.0 150.0 FSPD min/max speeds cm/s 

-19.0 19.0 FXTL pitch (x axis)degrees 

-19.0 19.0 FYTL roll (y axis)degrees 

 0.0 360.0 FHDG heading degrees 

-99999 999999 FXPR pressure decibars 

0 100 FEAM echo amp. db 

1 10 FRT1 limits for bin to use

***************************************************************************

All Nortek AQDs are assigned as instrument (ADCP) type “5” in the DAS control file 

(see Table 6). Specific parameters of the criteria file are associated with each 

instrument type. The criteria parameters of the Nortek Aquadopp are speed, pitch, 

roll, heading, water temperature, echo amplitude, and limits for bin to use. Criteria 

ranges are site specific and based on long term data trends. Table 6 contains an 

example of a control file for Buoy 2CH at Cape Henry Light Wreck of Lower 

Chesapeake Bay. 
99

Table 6. Sample control file for Buoy 2 CH 

************************* Sample Control File ******************************* 

cb0102 station id (Nortek s/n 0895) 

Buoy 2CH station name 

i073 instrument id number 

 calib id number adcp 

 calib id number press 

 calib id number temp 

 calib id bumber cond 

/tables/critr criteria id number 

/ports absolute unix directory path 

/archive raw hex data path 

/tables/calib calib table path 

/tables/instr instrument table path 

/tables/locat station table path 

 36 57 33 latitude north 

 76 00 46 longitude west 

71.0 charted depth feet 

71.0 fathometer reading feet 

(uncorrected) 

soft, sand bottom type 

39.00 ht. trans. above bottom inches 

 weather 

 divers’ observations 

33. length of deployment days 

rt operational mode (rt or sc) 

05 22 2000 20.817 start time first record m d y hh.hh gmt 

 stop time last record m d y hh.hh gmt 

25 number of bins sampled 

1.0 bin length meters 

1 pulse rep. rate seconds 

1 transmit interval seconds 

1.0 depth cell length meters 

0.0 blanking time 

0.4 blanking distance meters 

120 # pings per ensemble 

25 % good threshold 

1.00 time between pings seconds 

360 ensemble period seconds 

-10.8 compass deviation degrees 

adcp/devel processed data file path 

0 speed range (0=low,1=high) 

25.0 salinity ppt 

298 flood direction degrees True 

117 ebb direction degrees True 

0 adcp orientation, see devel.f (1-4) 

4 4 20 4 bin to use for real-time 

5 local standard time zone hours 

5 adcp type (0=narrowband,1=broadband,2=sontek) 

0 time used in this instrument (GMT=0) 

01010000000000000000000000000000 Sensors installed 

******************************************************************************
100

Processing checks include leader checks where the following are consistent from one 

time stamp to the next. If not, then data are flagged and stored in a log file. 

• instrument serial number 

• transducer serial number 

• frequency of the sensor 

• firmware version 

• coordinate system 

• number of cells 

• cell size 

• transmit length 

• sampling interval 

• averaging interval 

• blanking distance 

• pings per ensemble 

• compass update rate 

• AquaPro software version that created the configuration file 

The error and status codes listed in the first line of the PUFFF file are not qualitycontrolled through the criteria file; since there are no range limits, they are either 

good or bad. If any of the status and error codes fail, then the data are ingested into 

the database without being disseminated. 

CORMS. CORMS is a quality control and decision support system that combines 

use of real-time communications, data analysis, system monitoring graphical user 

interface (GUI), and system “watch dog” and notification capability. The objective of 

CORMS is to have the capability of 24-hour per day monitoring and quality control to 

ensure the availability and accuracy of tide, meteorological and current observations 

that are used for navigation and safety of life and property decisions. 

CORMS functions include: 

• ingest real-time and near real-time data and information 

• determine data completeness 

• measure data quality 

• generate statistics used to evaluate system performance 

• provide decision making information for possible field team response 

• communicate to real-time and near real-time users the identification of invalid 

or suspect data 

ATON current data are fed to the CORMS system just like any other sensor that 

CORMS monitors (Figure 83). The CORMS Operators have Standard Operating 

Procedures (SOPs) for all instrument data types (Appendix C). CORMS operators 

use these SOPs when monitoring ATON current data. 
101

Figure 83. ATON current data fed to CORMS, current profiler stations are labeled “cu” 
102
103

7.0 PRESENT PRODUCT SUITE

The products generated for current data derived from ATON-mounted current 

profilers are identical to those from bottom-mounted systems in PORTS®. There is a 

composite page as shown in Figure 84, plus a three-day time-series of currents. Data 

are also available in text form and on the voice system. PUFFF files are generated 

and made available for all ATON current data. In addition to the web-based graphics, 

harmonic constants of the buoy-mounted current data can be produced after at least 

30 days of good data are acquired. The predictions from PORTS® stations may also 

be published in the NOAA Tidal Current Tables if deemed necessary. 

 

 

Figure 84. Composite page from PORTS®
104
105

8.0 RECOMMENDATIONS AND NEXT STEPS

Successful deployment of this system represents an important step forward for the 

PORTS® Program. The multi-year test and evaluation process has been challenging 

at times, however CO-OPS can now release ATON current observations to the public 

as part of the CO-OPS suite of real-time products. CO-OPS plans to continue to 

enhance current information provided by the ATON system by investigating 1) the 

use of a GPS compass during calibration to produce a refined compass correction 

table, and 2) better methods for compensating for the ATON’s motion. 

CO-OPS management personnel have reviewed this document and concur that the 

evaluated sensor/system, when deployed and implemented as described herein, meets 

the defined requirements and is suitable for operational use. While additional testing 

may lead to superior performance or more economical operation, the existing 

sensor/system configuration is sufficient as described for use in the PORTS® program. 
106

ACKNOWLEDGMENTS

The development, testing, and implementation of ATON-mounted current 

measurement systems have truly been a team effort, with many individuals and 

groups playing key roles. The authors are grateful to the important contributions of: 

• Ron George of the Oceanscience Group, not only for his innovative mounting 

design, but his continued interest and efforts to improve the system; 

• Dr. Lee Gordon for integrating the Nortek current profiler into the current 

measurement system and for helping to refine the compass calibration 

procedure; 

• Malcolm Williams of Nortek USA, who continues to provide superb technical 

support to CO-OPS. He designed and built the power and communications 

module for the clamparatus, continues to investigate radio transmission 

deficiencies, and has even accompanied CO-OPS personnel on several site 

visits; 

• Atle Lohrmann of Nortek, who has made Nortek technical resources available 

to the project; 

• The USCG Fifth District ATON Team and John Walters for the foresight and 

flexibility which allowed the deployment of these systems; 

• The Maryland Port Administration for funding the development of these systems; 

• Captain Joseph Smith of the Association of Maryland Pilots for championing 

the ATON project and providing valuable user feedback during the 

development process; 

• John Stepnowski, Larry Neeson, and Mark Erickson of CO-OPS Field 

Operations Division for providing excellent vessel and field support for the 

many evaluation deployments; 

• Bradford Wynn, Sarah Mrozek, John Abbitt, Chris Metzger, Dave Hatcher, 

Kyle Dinberg, James Lewis, and Joe Taylor, also of CO-OPS Field Operations 

Division, for stepping in to help on several ATON field cruises; 

• Cathryn Primrose and Jan van Smirren of Fugro GEOS for planning and 

carrying out the intercomparison done in Freeport, TX; 
107

• Dr. Arnoldo Valle-Levinson, Jose Luis Blanco-Garcia, David Salas Monreal, 

and Richard Moody of Old Dominion University, for performing a ship-based 

comparison at ATON 2CH; 

• Captain John Gunning and the pilots of the Brazos Pilots Association; 

• Volker Eyermann, Vice President of Engineering, Freeport LNG LLC, for 

allowing their data to be used in the comparative study; 

• The USCG Eighth District Aids-to-Navigation Branch in Houston, TX for 

their quick approval of the Freeport comparison project; 

• Chris Paternostro and Mike Newton for Piney Point bottom-mounted current 

profiler deployment; 

• Charles Payton, James Sprenke, and Ayanah George of CO-OPS 

Requirements and Development Division, for performing tow tests at the 

Naval Surface Warfare Command, Carderock Division, David Taylor Tow 

Facility. 
108

VENDOR CONTACTS

NortekUSA

 Malcolm A. Williams 

 (410) 295-3733 

 222 Severn Avenue, Suite 17 

 Annapolis, MD 21403 

 mwilliams@nortekusa.com 

The Oceanscience Group

 Ron George 

 (760) 754-2400 

 110 Copperwood Way, Suite E 

 Oceanside, CA 92054 

 rgeorge@oceanscience.com 

MaxStream, Inc.

 355 South 520 West Suite 180 

 Lindon, Utah 84042 

Sutron 

 Tony Scott 

 (703) 406-2800 

 21300 Ridgetop Circle 

 Sterling, VA 20166 

AirLink Communications

 Mary Brandow 

 (719) 528-8778 

 mary@airlink.org
109

RELATED DOCUMENTS

 Gordon, L., George, R., and Portz, H., Third Generation Current Profiler 

Simplifies Port Monitoring, Compact New Current Profiler Speed Buoy Retrofit for 

Real-Time Data. Sea Technology, October 2000. 
110

ACRONYMS

ADCP Acoustic Doppler Current Profiler

ah Ampere-hours

AQP Aquadopp Profiler

ASCII American Standard Code for Information Interchange

ATON Aid to Navigation

Bps bits per second 

CCPO Center for Coastal and Physical Oceanography 

cm/s Centimeters per second

CDMA Code Division Multiple Access

CECAT Coastal and Estuarine Current Analysis Team 

CO-OPS Center for Operational Oceanographic Products and Services

CORMS Continuous Operational Real-time Monitoring System

COTS Commercial Off The Shelf

CSU Channel Service Unit

DAS Data Acquisition System 

DC Direct Current 

DCP Data Collection Platform

DIS Data Ingestion Server

DLL Dynamic Linked Library

DMS Data Management System

DSU Data Service Unit

FOD Field Operations Division

GMT Greenwich Mean Time

GPS Global Positioning System

IP Internet Protocol

ISD Information Systems Division 

KHz Kilohertz

LBB Lighted Bell Buoy

LCD Liquid Crystal Display

m Meters 

mA Milliamps 

MPA Maryland Port Administration

NCOP National Current Observation Program

NGWLMS Next Generation Water Level Measurement System

NIST National Institute of Standards 

nm Nautical Miles 

NOAA National Oceanic and Atmospheric Administration

NOS National Ocean Service 

NPDB National Ports Database 

NSWC Naval Surface Warfare Center

NWLON National Water Level Observation Network

OSTEP Ocean Systems Test and Evaluation Program
111

PCS Personal Communication System

POC Point of Contact

PORTS® Physical Oceanographic Real-Time System 

PSD Products and Services Division 

PUFFF PORTS® Uniform Flat File Format

PV Photovoltaic 

QA Quality Assurance

QC Quality Control

RDD Requirements and Developments Division

RDI RD Instruments 

s.d. Standard Deviation

SLL Sutron Dynamic Linked Library

TOL Tides On-Line

USACE United States Army Corps of Engineers

USACE/FRF United States Army Corps of Engineers / Field Research Facility

USCG United States Coast Guard 

XRTT Radio Transmission Technology 

WH Watt-hours 

3D Three-Dimensional 
112
113

APPENDICES
114

APPENDIX A - AQUADOPP SPECIFICATIONS

Acoustics:

 * Three acoustic frequencies: 0.6 MHz, 1 MHz and 2 MHz 

 * Profiling range (nominal): 30–50 m (0.6 MHz), 12–25 m (1 MHz), 5–12 m (2 MHz) 

 * Minimum cell size: 1 m (0.6 MHz), 0.3 m (1 MHz), 0.1 m (2 MHz) 

 * Minimum blanking 0.5m (0.6 MHz), 0.2m (1 MHz), 0.05 m (2 MHz) 

Velocity:

 * Horizontal velocity range: ±10 m/s (extended range available) 

 * Accuracy: 1% of measured value ±0.5 cm/s 

 * Sampling rate: 1 s to several hours 

Sensors:

 * Compass (flux-gate, automatic up/down detection) 

 * Tilt (liquid level, max 30̊ tilt) 

 * Pressure (piezoresistive, resolution better than 0.005% of full scale) 

 * Temperature (resistive) 

External Sensors:

 * Two analog input channels (0-5V) can be input and integrated with the data structure 

Data Communication:

 * I/O: RS232 or RS422 

 * Baud rate: 300 to 115200 

 * User control: Handled via WIN32 software or ActiveX controls 

Data Recording:

 * Capacity: 5 MB, upgradeable with 20 MB or 76 MB extra boards 

 * Data record: 32 bytes + 9×Ncells 

Mechanical:

 * Weight in air: 2.4 kg (2.6 kg for 0.6 MHz) with alkaline batteries 

 * Weight in water: Neutral 

 * Dimensions: 75 mm diameter, 550-600 mm length 

 * Materials: Standard model in plastic, full ocean depth models (2000 m and 6000 m) 

 in titanium and plastic 

User Choices:

 * Range for pressure range (default is 200 m) 

 * Recorder size (default is 5 MB, 25 and 81 MB available) 

 * External battery housing (5, 10, or 20 times standard battery capacity) 

 * Internal wiring harness (RS232+synch+analog out, RS422+synch, or RS232+analog in) 
115

Water Velocity Measurement 

Acoustic frequency 0.6 MHz 1.0 MHZ 2.0 MHz 

Maximum profiling range*) 30 – 50 m 12 – 25 m 5 - 12 m 

Cell size 1 – 4 m 0.3 – 4 m 0.1 - 2 m 

Minimum blanking 0.50 m 0.20 m 0.05 m 

Maximum # of cells 128 

Velocity Range ±10 m/s (call for extended 

 range) 

Accuracy 1% of measured value ± 0.5 

 cm/s 

Max. Sampling rate 1 Hz 

Velocity uncertainty Consult software program 

The Aquadopp profiler measures the current profile in 

a user specified number of cells from the instrument out 

to a maximum range that depends on the acoustic scattering 

conditions. The lower range should be expected with clear 

water and small cells and the higher range with large cells 

and acoustically turbid water. 

Echo Intensity 

Sampling Same as velocity 

Resolution 0.45 dB 

Dynamic range 90 dB 

Transducer 

Frequency 0.6 MHZ 1.0 MHZ 2.0 MHZ 

Number of beams 3 3 3 

Beam width 3.0̊ 3.4̊ 1.7̊

Standard sensors 

Temperature Type Thermistor embedded 

Range -4̊C to 30̊C 

Accuracy/resolution 0.1̊C/0.01̊C 

Time response 15 min 

Compass Type Flux gate with liquid tilt 

Maximum tilt 30̊

Accuracy/resolution 2̊/0.1̊

Tilt Type Liquid level 

Accuracy/resolution 0.2̊/0.1̊

Up or down Automatic detect 

Pressure Type Piezoresistive 

Range 0-100 m (standard) 

Accuracy/resolution 0.25%/0.005% of full scale 

Analog inputs 

Number of channels 2 

Voltage supply Battery voltage. Hardware can be 

 modified to provide 5 V or 12 V. 

Voltage input 0-5 V 

Resolution 16 bit A/D 

Serial Data Communication 

I/O RS232, RS422 

Baud rate 300-115,200 (user setting) 

Internal Recording 

Capacity 5 MB, expandable to 25MB or 81MB 

Data record 32 bytes + 9*Ncells 

Mode Stop when full (default) or wrap mode 

Software “AquaPro” 

Operating system WIN 32 (WIN 95/98/00, NT 4.0) 

Functions Deployment planning, data 

 retrieval, ASCII conversion, 

 online data collection and 

 graphical display 

Power 

DC Input 9-16 VDC 

Max consumption at 1Hz 0.2-1.5 W 

Sleep consumption 0.0013 W 

Transmit power 0.3-20 W, 4 adjustable levels 

Internal Batteries*) 

Type/capacity 18 AA Alkaline 

cells/50Wh 

New battery voltage 13.5 VDC 

Duration (10-minute avg.) 120 days for 2MHz, 0.5 m 

 cells 

Duration (10-minute avg.) 90 days for 1MHz, 1.0 m 

 cells 

Exact battery consumption and velocity uncertainty are 

complex functions of the deployment configuration. 

Please consult the AquaPro software for more exact 

predictions. 

Materials 

Standard Delrin and polyurethane plastics 

 with titanium screws 

Intermediate and Titanium and Delrin plastics 

Deep water models

Connectors 

Bulkhead (Impulse) LPMBH-8-FS (bronze) 

Cable LPMIL-8-MP on10-m 

 polyurethane cable 

Environmental 

Operating temperature - 5̊C to 35̊C 

Storage temperature - 20̊C to 45̊C 

Shock and vibration IEC 721 – 3 – 2 

Shallow water rating 300 m 

Deep water rating 2000 and 6000 m 

Dimensions 

Weight in air 2.4 kg/2.6 kg (0.6 MHz) 

with alkaline batteries 

Weight in air (deep water) 6-10 kg, depending 

 on model 

Length 550 mm 

Diameter 75 mm 

Options 

Batteries Lithium 

External batteries 200 Wh, 540 Wh or 1080 Wh 

alkaline 

Bulkhead connectors Titanium instead of bronze 

Transducer head Side-looking for 1 or 2 MHz. 

 Inquire for special 

 configurations 

Communication: Request special harness for 

 RS422 communication. Inquire for 

 cables > 100 m 
116

APPENDIX B - CORMS SOPS

OPERATION PROCEDURE 1

 CORMS NOTIFICATION OF CO-OPS STAFF

FOR A

COMMUNICATIONS FAILURE BETWEEN A DAS AND CORMS 

Updated: 1 April 2004

Introduction and Purpose 

This procedure describes the interaction between CORMS and CO-OPS staff before, 

during, and after a communications failure between the main CORMS and all sensors in a 

particular PORTS® estuary system. This communications failure may take the form of 

all sensors reporting black condition or red condition. The condition for all black sensor 

indicators is the failure of communications between TESTPORT Computer located in 

SSMC-2 and the DAS. Ordinarily, this has occurred due to Internet failure (MCI 

WorldCom) or CSU/DSU Modem, or DAS or router failure. The general case for the all 

red sensor indicator is a failure of any data to arrive at the DAS. This failure can occur 

due to local hardware/communications problems. 

ISD has developed software that detects the all-black condition and uses phone to contact 

the DAS and receive data. Notification to CORMS is under development, because the 

all-black is transparent, since telephone communications would mask the problem. 

Currently, CORMS receives an e-mail in the morning indicating what PORTS® were 

dialed and how often. Additional mail may be developed to notify operations of an 

existing situation after one hour. In the meantime, should something indicate that a 

blackout has occurred, for the six PORTS® on the text screen on the O2, updates will stop 

taking place. 

Importance of keeping people informed cannot be stressed enough. The POC list 

identifies who should receive e-mail for different problems. Although most discussions 

needed to resolve the issues are conducted verbally, it is important to keep a log of each 

incident where e-mail is unavailable and supplement that with e-mail at a later time. 
117

PROCEDURE

ALL SENSORS BLACK CONDITION

1. If while monitoring the Main CORMS Screen, all of the sensor data quality 

indicators within a particular PORTS® estuary change color to black, this indicates 

a communications failure between the port DAS and the active TESTPORT 

computer (the terminus for all of the Internet connections to the PORTS®). There 

are now two TESTPORT computers that will automatically switch if one fails. 

2. If other PORTS® are communicating normally, there is no need to verify that the 

TESTPORT 1 computer is working. If all other PORTS® are experiencing the 

same difficulty, then there could be a problem with TESTPORT 1 and 2 or a local 

HUB has stopped. 

3. This error must be handled promptly. The CORMS operator will determine the 

time of the outage and make an entry into the Passdown Log. 

4. The operator will then link to the Intranet page http://co-ops.nos.noaa.gov/intranet. 

You may also reach this page through the link provided on the CORMSLINKS 

page. Select “CORMS Troubleshooting”. Select “PORTS/CORMS Network 

Troubleshooting”. From this page, you will be able to perform a “traceroute” or 

“ping” from TESTPORT 1 to the primary or the backup DAS and the prescribed 

routers. The traceroute should be run to see where in the communication line is 

the data transmission being interrupted. 

****Anchorage/Nikiski, Soo Locks, Tacoma and LA/Long Beach represent 

departures from the procedure below, they do not have MCI lines***** 

 

When this command is successful, the IP address of the PORTS® should be the last line 

before the system displays DONE indicating that the traceroute was successful. When a 

traceroute fails, the command never displays the IP address of the PORTS® on the last 

line. 

There is a suggestion that the last IP address displayed is a good indication of where the 

interruption may have occurred. 

5. Should the traceroute fail, the operator will contact MCI/WorldCom, personnel 

about the current outage. When placing the call, you must have the following 

information available: the circuit ID and the IP address. The CORMS operator 

should state “I am having trouble with one of my internet circuits. Its circuit ID 

is ...”. MCI/WorldCom will check out the line and give you a case number. It is 

mandatory that the operator record this number in the Passdown log and the 

Morning Report, as it will be yours and MCI/WorldCom personnel’s tracking 

number for the problem. An e-mail detailing facts will also be sent to the POC 

list. 
118

6. At this point, the CORMS operator will follow instruction from the 

MCI/WorldCom personnel for further action. You may be required to call local 

site personnel if available for supporting the equipment to restart the CSU/DSU, 

routers or hubs. It is important to note that assistance is sometimes rendered by 

individuals who are not associated with the program, nor are they compensated 

for this work. Be thoughtful and patient. The Intranet site contains photographs 

of our instruments that could provide help; these will not be available to anyone 

outside the office because of the security. These personnel may not be available 

after normal business hours. Notify the PORTS® Operations Manager when this 

occurs to determine what actions to take next. 

7. Documentation is required of all actions and conversations during the entire 

process of restoring communications. Advise MCI/WorldCom personnel that 

you must provide status reports to users and you will call periodically for 

updates. Make these status reports available to the POC list. Notify the 

PORTS® Operations Manager if there are problems resolving the situation either 

with MCI/WorldCom or site help. 

8. During this time, there is no need to stop dissemination of the data. Since 

communications are the apparent problem, return to normal status should 

produce no sensor problems. Monitor the data when the condition changes back 

to green. In the meantime, monitor the sensors if they are transmitting through 

the satellite. 

9. Be sure to notify any PORT that has a 24-hour monitor of the PORTS® Pages 

(New York, Houston and Soo Locks) that CORMS is unable to provide 

appropriate monitoring of the data and also notify them of the resolution. 

ALL SENSORS RED CONDITION

1. San Francisco represents the only remaining PORTS® that could produce an all 

red condition. If all of the sensors in the estuary change color to red, this is 

generally an indication of no data at the DAS. The communications for San 

Francisco are exclusively IP Modem and if the DAS can not get out to the 

internet to poll for the data, an all red condition could occur. 

2. If the condition continues for one hour, change communications for those 

stations that have alternate communications. Notify the on-call ISD contact with 

a page if this does not resolve the issue. Do not stop dissemination, when the 

error clears, data should resume. 
119

OPERATION PROCEDURE 2 

CORMS NOTIFICATION OF AND INTERACTION WITH CO-OPS STAFF

FOR A 

“NO DATA FAILURE” OF AN INDIVIDUAL PORT® SENSOR

Updated: 1 April 2004 

INTRODUCTION AND PURPOSE

This Operational Procedure describes the interaction between CORMS and support staff 

before, during, and after the failure to receive data from an individual sensor. The 

importance of keeping people informed can not be stressed enough. Communications to 

all responsible parties is important to the determination of the problem and the 

subsequent solution. 

In each case where an e-mail is specified one individual is to be the addressee with copy 

(CC) to others, making it clear that the addressee is the sole person responsible for taking 

action (review the mail POC list for each PORT). The others are being kept informed or 

may provide some ancillary information or action through the individual who would be 

responsible. 

PROCEDURE

1. If a “Failure No Data Found” (FNOD or FNDF) QC flag has been displayed on 

the Main CORMS Screen for an individual sensor for thirty minutes, the 

operator should attempt to switch to the alternate form of communications if 

available (see interrogation method list on the on off page of Main CORMS). 

Should data recover, no further action is necessary, except to notify the POC list 

of the error and the change in communications. Should the errors persist for 

thirty additional minutes, then the operator should switch back to the previous 

communications scenario. Dissemination (PICS, TEXT, VOICE,) must be 

stopped if the error is continuous for one hour. When dissemination is stopped, 

the operator will send an e-mail immediately to the site representative and the 

POC list detailing the issue, a response from the appropriate site manager should 

follow before close of business, provided it is not too late in the day. During off 

duty hours, Monday through Friday and weekends, the operator will send an email to the site representative and the POC list which will detail the issue, but 

there may be no response until the next business day. As soon as possible after 

stopping dissemination, the status page must be updated. 

2. Prior to sending e-mail or calling anyone, the operator should determine if any 

other co-located sensors (i.e. WL, Met, CT) that use the same communications 

path are experiencing the same problem. If all are sending FNOD, the error is 

possibly communications. If it is just one of the sensors, WL or MET or CT, 

then there could be a sensor problem. What do the previous plots show about 

the data (i.e. sporadic) other problems indicating a history of problems? 
120

Maintenance work just completed could be a problem. Is the data available in 

NPDB, TIDES On LINE (TOL) or other means? Is there a weather event 

happening? Results of any evaluation should accompany the e-mail as 

additional information, not a conclusion; let the field engineers determine this. 

3. CORMS staff should monitor the station in the plotting tool to determine if the 

station begins sending data again and whether or not the data is good. The Red 

failure indicator on the main CORMS screen (indicating a sensor failure) will 

return to green when data has resumed and has passed quality control checks at 

the DAS. Monitor the plotting tool closely and restore the dissemination when 

data resumes, after reviewing several data points (Refer to Operational Order 4 

for guidance). 

4. The FOD Site Representative will schedule service either by FOD personnel or 

by the local O&M contractor should the error persist. 

5. The individual responsible for local O&M will diagnose, resolve, or repair the 

problem and document by e-mail to the FOD Site Representative with CC to 

POC List. CORMS will place a brief notice of the incident and resolution in the 

Morning Report and the PORTS® Instrument Status Page. The Site 

Representative shall determine whether a statement needs to be generated to 

appear on the PORTS® page. The PORTS® Field Operations Manager should 

generate any statement and forward it through the PORTS® Program Manager 

for updating the PORTS® Page. 

6. Upon receipt of notification that the sensor repair was affected, depending on 

the type of repair, CORMS will either review the data using the plotting tools 

notify the oceanographer to begin reviewing the data as per Operational 

Procedure 6. Upon appropriate review, the operator will restart data 

dissemination. 

OTHER ACTIONS

1. If a no data failure continues and dissemination is stopped, communications will 

continue via satellite. Monitor this data to ensure the quality if the data fails to appear at 

the appropriate transmit time. 

2. If satellite communications fails to produce data, stop dissemination in TOL and send 

e-mail to the POC list for the PORT indicating this also. 
121

FAILURE/MAINTENANCE COMMUNICATION PROCEDURES

1. Upon arrival at the station, the FOD or contractor field team will notify the CORMS 

watch that maintenance and/or repairs are to take place. CORMS will ensure that 

dissemination of the data is stopped at this time. An e-mail will be sent to the POC list 

and a phone log will be made stating the time data dissemination was stopped, who is 

performing maintenance, when it is complete, and reason for turning it off. 

2. Once field team has finished performing the necessary repairs and/or maintenance, 

they will contact CORMS. CORMS will, depending on the nature of the repair, notify 

the responsible Oceanographer (see Operational Order 4) or, if it is not a major repair, 

immediately begin to review data using the Plotting Tool. 

3. CORMS personnel will contact the field crew within twenty minutes acknowledging 

the data that has or has not been received. Begin reviewing the data and compare it with 

other sensors. Dissemination will be restarted at this time if repairs were not of a nature 

that an oceanographer need be involved. If data is not received or is questionable, 

CORMS will inform the field crew of this within the same time frame. 
122

OPERATIONAL PROCEDURE 3 

CORMS NOTIFICATION OF AND INTERACTION WITH CO-OPS STAFF

FOR ISSUES OF 

“DATA OF SUSPECT QUALITY” FROM AN INDIVIDUAL PORTS® SENSOR

Updated: 1 April 2004 

INTRODUCTION AND PURPOSE

This procedure describes the required interaction between CORMS and support staff 

before, during and after an issue arises where the quality of data from an individual 

sensor is questionable. The importance of keeping people informed can not be stressed 

enough. Although a vast majority of the communications needed to resolve a given issue 

may take place verbally, a written log should be created for each incident where mail 

is not possible (i.e. CORMS “Passdown” Log or the CORMS Phone 

Communications Log). 

PROCEDURE

1. If, while monitoring the PORTS® data, an issue arises as to the quality of the 

data from an individual sensor, the CORMS Operator will immediately halt 

dissemination of the data products (Text, PICS, Voice, TOL). It may be 

difficult to determine if the quality is bad from just one sample, so it is advisable 

to wait until a second sample appears to make a decision. The issue may be 

manifest in a variety of ways, including significant departure from predictions, 

unusual readings relative to neighboring sensors, flat readings for consecutive 

samples, or other intermittent or questionable behavior. During normal business 

hours, the CORMS Operator will contact the PORTS® Site Representative as 

indicated in the Point of Contact List (POC) for each estuary via e-mail. The 

same e-mail will inform the other members of POC list of the situation . During 

off-duty hours, during the week, and on weekends, the appropriate e-mail will 

be sent informing the list, but no further action should be taken without 

authorization from the PORTS® Operations Manager. For data quality issues, 

under no circumstances should anyone be contacted overnight unless there is a 

request to do so and without first contacting the PORTS® Operations Manager. 

2. The FOD Site Representative will initiate any and all field contact regarding the 

matter and notify all necessary individuals unless there is a request that CORMS 

do so. CORMS will provide any assistance to the site representative that may be 

required. 

3. The FOD Site Representative will contact the individual responsible for local 

O&M who will diagnose and repair the problem. Upon notification by the 
123

appropriate individual, CORMS will place a brief notice of the incident and 

resolution in the shift turnover log and the Morning Report. 

4. Upon receipt of notification from the appropriate individual, that the sensor 

repair was satisfactorily completed, and, depending on what that repair entailed, 

CORMS may evaluate the data using the appropriate tool and restart 

dissemination. Should the repair require new sensors with different offsets or 

calibration, CORMS will notify the respective oceanographer (See Appendix 4) 

for water levels or currents, that the data is available for review. Upon 

notification from the responsible oceanographer, dissemination will be restarted 

and e-mail will be sent to the POC list. During off duty hours, nights and 

weekends, CORMS will not contact an oceanographer but will notify the 

individual by mail with a cc to the Senior Tech who will track action. 

5. For any outage, a notice shall appear in the PORTS® Instrumentation Status 

Page. For long-term outages, a statement will be generated by PORTS® Field 

Operations Manager and will be forwarded to ISD through the PORTS®

Program Manager for inclusion into the appropriate PORTS® Web Page. 

 

PRELIMINARY STEPS FOR EVALUATING DATA

1. Review adjacent sensors to verify erroneous/questionable data. 

2. Review local meteorological reports for anomalous weather events that would 

be responsible for questionable data. 

3. Report only what can be seen with the tools you have. Report any error flag that 

the CORMS system is identifying. 

*****The CORMS Operation is the final Quality Control point. If the operator analysis 

indicates that there is still a question regarding the data after repair, do not start 

dissemination, and contact the PORTS® Operations Manager immediately.********* 
124

 Ancillary Requirements

1. Update the CORMS Instrument Status Page. 

2. Long-term outages require a statement on the PORTS® web page to be generated 

through the PORTS® Program Manager. The PORTS® Operations Manager will 

be responsible for contacting the appropriate individual to generate the message. 

3. Stop Tides On Line dissemination. 
125

FAILURE/MAINTENANCE COMMUNICATION PROCEDURES

I. The FOD or contractor field team will notify the CORMS watch upon arrival at 

the station that maintenance and/or repairs are to take place. CORMS will 

ensure that dissemination of the data is stopped at this time. An e-mail will be 

sent to the POC list and a phone log will be made stating the time data 

dissemination was stopped, who is performing maintenance, and reason for 

turning it off. 

II. Once field crew has finished performing the necessary repairs and/or 

maintenance, they will contact CORMS. CORMS will, depending on the nature 

of the repair, notify the responsible Oceanographer (see Appendix 4) or if it is 

not a major repair, immediately begin to review data using the Plotting Tool. 

III. CORMS personnel will, if requested, contact the field crew within twenty 

minutes of acknowledging that the data have or have not been received. Begin 

reviewing the data and compare it with other sensors. Dissemination will be 

restarted at this time if repairs were not of a nature that an oceanographer need 

be involved. If data is not received or is questionable, CORMS will inform the 

field crew of this as soon as it is detected. 
126

APPENDIX C - AQUADOPP ERROR AND STATUS WORDS

The Aquadopp Profiler outputs two multiple bit binary coded words describing the 

instrument state. The following explains the meaning of each bit in the Error and Status 

words. The bits within the words count from right to left starting with zero. 

Error word: 

The bit is set (‟1‟) if there is an error condition and cleared (‟0‟) if OK. 

Bit 7 Coordinate transformation: If the compass fails and the system is set to ENU, 

the system will output XYZ and this bit will be set. 

Bit 6 Sensor: Vector: The tilt sensor is not responding. Aquadopp: The CT sensor 

(serial only - i.e. Seabird) is not responding. 

Bit 5 Beam number: A problem has occurred with the beam order. 

Bit 4 Flash: An error has occurred in the primary system flash memory, and the 

system may not be able to reboot. 

Bit 3 Tag bit: There has been an error in the processing, an internal buffer is 

overflowing. 

Bit 2 Sensor data: One of the sensors is not operating correctly. 

Bit 1 Measurement data: An error has occurred with some element of the processing, 

the data is probably corrupt. 

Bit 0 Compass: The compass does not respond. If the system is in ENU mode, it 

will default to XYZ, and a value of 90 degrees will be displayed. 

Status word: 

Bits 7 and 6 Power level: These bits reflect the power level setting, i.e. how much 

acoustic energy the instrument transmits into the water. This is set by 

the user in the deployment planning dialog when configuring the 

instrument. 

Bit 7 Bit 6 Power level 

0 0 High 

0 1 High - 

1 0 Low + 

1 1 Low 
127

Bits 5 and 4 Wake-up state: These bits indicate the Wake-up state of the 

instrument. There are four different ways to cause a wake-up of the instrument; hence, 

there are two bits in the status field that identify the wake-up source. 

Bit 5 Bit 4 Wake-up state 

0 0 Bad power 

0 1 Power supplied 

1 0 Break 

1 1 Real Time Clock (RTC) 

Bad power status is used when the input voltage to the instrument during normal 

operation is so low that the instrument may no longer operate correctly. The hardware is 

then held in a reset state until the voltage reaches an acceptable level. It is typically 

caused by a broken cable or a faulty power supply. 

Power supplied is the status code when power is applied to an instrument. To get this 

status code, the power must be removed for a few seconds. Removing power for just one 

second will typically be indicated as bad power. 

Break status indicates an instrument reset because a break was received on the 

communications port. The break is used when the software communicates with the 

instrument. This will typically be status code in the first data record in an online 

measurement. 

Real-Time Clock (RTC) status shows that the internal clock in the instrument caused the 

Wake-up. To reduce the power consumption, the instrument enters sleep mode between 

measurements for most setups. The internal RTC will ensure that the instrument wakes 

up at the appropriate time, and this is indicated in the status byte. 

Bit 3 Roll: This bit indicates if the instrument roll angle exceeds the tilt sensor 

operational range limits. 

Bit 3 Roll 

0 OK, valid data 

1 Out of range, invalid data 

Bit 2 Pitch: This bit indicates if the instrument pitch angle exceeds the tilt sensor 

operational range limits. 

Bit 2 Pitch 

0 OK, valid data 

1 Out of range, invalid data 

Bit 1 Scaling: This bit indicates the scaling of the velocity output and depends on the 

velocity range setting (Vector only). If the instrument is set to use the highest 
128

ranges, the least significant bit is one mm/s. For the lowest range it is 0.1 mm/s. 

The purpose of varying the scale factor is to make sure that we use as much as 

we can of the dynamic range that is inherent in the system. This is all 

transparent if you use the Vector program to convert to ASCII because the data 

reported in the ASCII files is in engineering units. If you develop your own 

programs to read the binary data files, the variable scaling must be taken into 

account. 

Bit 1 Scaling 

0 1mm/s 

1 0.1 mm/s 

Bit 0 Orientation: This bit indicates the orientation of the instrument. 

Bit 0 Orientation 

0 Up 

1 Down