Marine Sanctuaries Conservation Series ONMS-06-05

U.S. Department of Commerce 

National Oceanic and Atmospheric Administration

National Ocean Service 

Office of Ocean and Coastal Resource Management 

Comments on Hydrographic and Topographic 

LIDAR Acquisition and Merging with Multibeam 

Sounding Data Acquired in the 

 Olympic Coast National Marine Sanctuary 

National Marine Sanctuary Program August 2006 
About the Marine Sanctuaries Conservation Series 

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Comments on Hydrographic and Topographic 

LIDAR Acquisition and Merging with Multibeam 

Sounding Data Acquired in the 

 Olympic Coast National Marine Sanctuary 

Steven S. Intelmann 

Olympic Coast National Marine Sanctuary, NOAA 

Silver Spring, Maryland

August 2006

U.S. Department of Commerce 

Carlos M. Gutierrez, Secretary 

National Oceanic and Atmospheric Administration 

VADM Conrad C. Lautenbacher, Jr. (USN-ret.) 

Under Secretary of Commerce for Oceans and Atmosphere

National Ocean Service 

John H. Dunnigan, Assistant Administrator 

National Marine Sanctuary Program

Daniel J. Basta, Director 
DISCLAIMER 

Report content does not necessarily reflect the views and policies of the National Marine 

Sanctuary Program or the National Oceanic and Atmospheric Administration, nor does 

the mention of trade names or commercial products constitute endorsement or 

recommendation for use. 

REPORT AVAILABILITY 

Electronic copies of this report may be downloaded from the National Marine Sanctuary 

Program web site at www.sanctuaries.nos.noaa.gov. Hard copies may be available from

the following address:

National Oceanic and Atmospheric Administration

 Office of National Marine Sanctuaries

 SSMC4, N/ORM62 

 1305 East-West Highway 

Silver Spring, MD 20910 

COVER 

Perspective view of Cape Flattery and Tatoosh Island. Hydrographic and topographic 

LIDAR data merged with shallow water multibeam soundings and gridded at 4 meter 

resolution. The nautical chart was masked in Fledermaus with data obtained from both 

the 10 kHz and 1 Khz lasers. 

SUGGESTED CITATION

Intelmann, S.S. 2006. Comments on hydrographic and topographic LIDAR acquisition 

and merging with multibeam sounding data acquired in the Olympic Coast National 

Marine Sanctuary. Marine Sanctuaries Conservation Series ONMS-06-05. U.S. 

Department of Commerce, National Oceanic and Atmospheric Administration, National 

Marine Sanctuary Program, Silver Spring, MD. 18 pp. 

CONTACT

Steven S. Intelmann 

Habitat Mapping Specialist 

NOAA/National Marine Sanctuary Program

N/ORM 6X26 

115 E. Railroad Avenue, Suite 301 

Port Angeles, WA 98362 

(360) 457-6622 X22 

steve.intelmann@noaa.gov 
ABSTRACT 

In April 2005, a SHOALS 1000T LIDAR system was used as an efficient alternative for 

safely acquiring data to describe the existing conditions of nearshore bathymetry and the 

intertidal zone over an approximately 40.7 km2 (11.8 nm2

) portion of hazardous coastline 

within the Olympic Coast National Marine Sanctuary (OCNMS). Data were logged from

1,593 km (860 nm) of track lines in just over 21 hours of flight time. Several islands and 

offshore rocks were also surveyed, and over 24,000 geo-referenced digital still photos 

were captured to assist with data cleaning and QA/QC. The 1 kHz bathymetry laser 

obtained a maximum water depth of 22.2 meters. Floating kelp beds, breaking surf lines 

and turbid water were all challenges to the survey. Although sea state was favorable for 

this time of the year, recent heavy rainfall and a persistent low-lying layer of fog reduced 

acquisition productivity. The existence of a completed VDatum model covering this 

same geographic region permitted the LIDAR data to be vertically transformed and 

merged with existing shallow water multibeam data and referenced to the mean lower 

low water (MLLW) tidal datum. Analysis of a multibeam bathymetry-LIDAR difference 

surface containing over 44,000 samples indicated surface deviations from 

–24.3 to 8.48 meters, with a mean difference of –0.967 meters, and standard deviation of 

1.762 meters. Errors in data cleaning and false detections due to interference from surf, 

kelp, and turbidity likely account for the larger surface separations, while the remaining 

general surface difference trend could partially be attributed to a more dense data set, and 

shoal-biased cleaning, binning and gridding associated with the multibeam data for 

maintaining conservative least depths important for charting dangers to navigation. 

KEY WORDS 

Hydrographic LIDAR, Topographic LIDAR, SHOALS, multibeam, VDatum, Olympic 

Coast National Marine Sanctuary 

i 
TABLE OF CONTENTS 

Topic Page

Abstract and Key Words......................................................................................... i 

Table of Contents.................................................................................................... ii 

List of Figures and Tables....................................................................................... iii 

Introduction............................................................................................................. 1 

Survey Area ............................................................................................................ 1 

Basic LIDAR Function ........................................................................................... 3 

LIDAR Data Acquisition and Processing............................................................... 3 

LIDAR Survey Product........................................................................................... 3 

Data Quality Along Exposed and Unexposed Coastline ........................................ 7 

LIDAR and Multibeam Merge................................................................................ 10 

Discussion and Conclusions ................................................................................... 14 

Acknowledgments................................................................................................... 16 

References............................................................................................................... 17 

Appendix................................................................................................................. 18 

ii 
LIST OF FIGURES AND TABLES

Figure/Table Number and Title Page

Figure 1. Cape Flattery LIDAR flight track lines, Koitlah Point to Cape Alava, 

shown with existing area of multibeam sounding data........................................... 2 

Figure 2. Locations of secchi measurements taken 15 April 2004........................ 4 

Figure 3. Surf breaks, kelp beds, and turbid water all created challenges for 

acquiring bathymetry data in the southern portion of the survey area.................... 5 

Figure 4. Combined hydrographic and topographic LIDAR coverage achieved 

over the six-day survey period shown with 10 m bathymetry contour .................. 6 

Figure 5. Adjacent stretches of exposed and unexposed coastline within 

the proposed survey area......................................................................................... 8 

Figure 6. Archived wave summary statistics from NDBC station 46087, April 

19-26, 2005 (UTC).................................................................................................. 9 

Table 1. Archived wave summary statistics from NDBC station 46087, April 

19-26, 2005 (UTC).................................................................................................. 9 

Figure 7. VDatum tide modeling grid for the San Juan Islands, Strait of Juan 

de Fuca and Puget Sound........................................................................................ 10 

Figure 8. Multibeam sounding data combined with bathymetry and 

topographic LIDAR data sets.................................................................................. 11 

Figure 9. Depth difference histogram.................................................................... 12 

Figure 10. Depth difference (90th percentile only) plotted against multibeam

sounding depth ....................................................................................................... 13 

Figure 11. Multibeam and LIDAR xyz data merged into seamless DTM 

covering Makah Bay............................................................................................... 13 

Figure 12. An Area of significant surface difference attributed to improper 

cleaning of the LIDAR data.................................................................................... 14 

iii 
iv 
INTRODUCTION

Airborne LIDAR (light detection and ranging) technology developed throughout the 

1990s is a new tool for use in bathymetric mapping. Today, airborne LIDAR bathymetry 

(ALB) has fully developed into a mature technology that is a cost effective means for 

quickly and efficiently obtaining bathymetry information, even in areas of hazardous 

conditions or in remote locations too difficult to survey through conventional acoustic 

methods (MacDonald 2005). 

The initial commercialization of this new technology is, in part, traceable to a 1998 

Memorandum of Agreement (MOA) between the U.S. Army Corps of Engineers 

(USACE) and the Naval Meteorology and Oceanography Command, which established 

the Joint Airborne LIDAR Bathymetry Technical Center of Expertise (JALBTCX) in an 

effort to create a mechanism for helping shape future developments and capabilities of 

ALB mapping (MOA1998). This original MOA was superceded in 2002 (MOA2002) by 

creation of a new MOA that added the National Oceanic and Atmospheric 

Administration’s (NOAA) National Ocean Service (NOS) and Office of Marine and 

Aviation Operations (OMAO) as partners. Expanding the breadth of partnership to 

include various facets of NOAA harnessed other existing capabilities, survey knowledge, 

tidal determination capabilities, and other unavailable resources. 

In March 2005, under the NOS agreement code, a Support Agreement (MOA-2002-047 

SA #001/1223) was written to facilitate the acquisition of LIDAR data for NOAA’s 

Olympic Coast National Marine Sanctuary (OCNMS) in Washington State. Under this 

Agreement, Fugro Pelagos, Inc. (FPI) was contracted by GRW Engineers to conduct a 

site survey for the USACE (and ultimately OCNMS) along a portion of coastline from 

Koitlah Point to Cape Alava within the OCNMS. OCNMS’ objectives for the survey

effort were three-fold: 1) to obtain existing conditions of the nearshore bathymetry and 

intertidal zone along a select portion of shoreline that is not ascertainable through shipbased acoustic data acquisition techniques due to hazardous surf conditions, 2) to assess 

the performance of ALB technology along both exposed and unexposed stretches of 

coastline, and 3) to vertically transform the ALB data and assess agreement with existing 

shallow water multibeam bathymetry data collected in the same area. 

SURVEY AREA 

Approximately 40.7 km2 (11.8 nm2

) of nearshore bathymetry and coastline between 

Koitlah Point and Cape Alava, in the general vicinity of Cape Flattery, and bounded by 

coordinates 48o

 08’38’’ N, 124o 47’34’’W, and 48o 24’46’’ N, 124o38’11’’W (Figure 1) 

were proposed for surveying with a SHOALS 1000T LIDAR system. Survey flights 

occurred, or were attempted, between April 19 and April 24, 2005, with data being 

logged from 860 nm (1,593 km) of track lines in just over 21 hours of flight time. 

Bathymetry data was targeted between the shoreline and the approximate 15 meter 

bathymetry contour or laser extinction, which ever came first. Bathymetry data from the 

1 kHz laser was acquired at 400 meters altitude, at 125 knots and with coverage plan 

1 
designed to obtain 4 by 4 meter spot spacing using 25 percent line overlap. During 

project design, topographic survey lines were created to obtain heights 100 meters 

shoreward or to the mean higher high water (MHHW) line, which ever came first. Data 

from the 10 kHz topographic laser was acquired at 700 meters altitude, at 155 knots and 

with coverage designed to obtain 2 by 1.6 meter spot spacing. Several islands and 

offshore rocks were also surveyed, and over 24,000 geo-referenced digital still photos 

were simultaneously captured to assist with data cleaning and QA/QC. 

 

Figure 1. Cape Flattery LIDAR flight track lines, Koitlah Point to Cape Alava, 

shown with existing area of multibeam sounding data (blue polygon). 

2 
BASIC LIDAR FUNCTION

The basic principle of topographic LIDAR operation involves transmitting light in the 

form of a laser onto a mirror that is rotated at a high rate of speed. The rotating mirror 

projects the laser as a series of pulses onto the ground. Light is reflected back to the 

instrument, and with known vessel position, two-way time travel is used to ultimately 

compute the positional measurement of reflecting objects. ALB systems, however, are 

more sophisticated in theory because they must compensate for multiple reflective 

surfaces (i.e., the water surface and the seafloor). As such, ALB systems function as a 

multiple phase system where two different waves (infrared and green) are respectively 

used to detect the sea surface and sea floor. The newest generation of ALB systems, such 

as the one used for this particular survey, employs both types of LIDAR systems making 

them ideal for mapping shallow water intertidal zones as both height and sounding 

measurements can be delivered as a seamless data set. A seamless hydrographic and 

topographic LIDAR data set can then potentially be merged with acoustically derived 

single or multibeam bathymetry data, although a vertical datum transformation will likely 

be needed if the LIDAR data is acquired in an orthometric vertical datum and the 

multibeam data is referenced to some tidal datum such as MLLW (National Research

Council 2004). 

 

LIDAR DATA ACQUISITION AND PROCESSING

Details of the LIDAR acquisition and processing are in the attached Appendix, entitled 

“Hydrographic & Topographic LIDAR Acquisition, Northwest Coast, Washington, Neah 

Bay to Cape Alava, WA Survey Report” prepared by the FPI data center. 

LIDAR SURVEY PRODUCT 

Numerous shoals and hazardous surf conditions exist throughout the survey area, thereby 

precluding the use of ship-based acoustic multibeam for mapping the extreme nearshore 

zone in this area. LIDAR provided an efficient alternative for safely acquiring additional 

information to describe existing conditions of the nearshore bathymetry and intertidal 

areas throughout the Koitlah Point to Cape Alava region. As a general rule, the SHOALS 

1000T (see Appendix for full description) is designed to obtain bottom depths of roughly 

2.5 to 3 times the secchi depth. On April 15, 2004, 11 secchi measurements were taken 

throughout the proposed survey area in an effort to anticipate potential LIDAR 

performance (Figure 2). Secchi measurements ranged from 3.2 to 8.7 meters, indicating 

that bottom detection could potentially be achieved to anywhere between 8 and 26 

meters, depending on water clarity at the time of the survey. 

All topographic survey lines were fully completed and achieved with desired results; 

however, consistently poor weather conditions and a low-lying fog layer prevented any 

data acquisition from occurring on two of the six available survey days compromising 

bathymetry data acquisition efforts. Temporary cloud cover further restricted flying time

3 
on three additional days. As a result, significantly less data was acquired during the sixday time frame than had been hoped for. Very little bathymetry data was obtained in the 

southern region of the survey area due to weather constraints on survey time, poor water 

clarity resulting from recent significant rainfall and dense areas of kelp in the water 

column (Figure 3). 

Figure 2. Locations of secchi measurements taken April 15, 2004. Secchi readings are 

in meters. Visual observations, if noteworthy, were also recorded at each site at the time

of the measurement. The blue line represents the 10 m contour and purple polygon

depicts the proposed survey boundary. 

4 
Figure 3. The graphic to the left represents the inset 

region of aerial photography provided below.

Surf breaks, kelp beds and turbid water all created 

challenges for acquiring bathymetry data in the 

southern portion of the survey area. All three 

challenges are clearly visible in the digital photo 

mosaic below. Images are overlaid with the

accepted height data acquired from both the 1 kHz

(bathymetry) and 10 kHz (topography) lasers. 

Example data are from the Tskawanyah Island area, 

and are gridded at 4 m resolution.

5 
The effect of water clarity and inclement weather on survey productivity is immediately 

apparent when overlaying the actual LIDAR coverage achieved with the proposed survey 

area as shown in Figure 4. 

 

Figure 4. Combined hydrographic and topographic LIDAR coverage achieved over the sixday survey period. Heights and soundings are color ramped from red (highest surface 

elevation) to purple (deepest water depth). Grey polygon represents the proposed coverage 

area. 

6 
The maximum water depth obtained by the 1 kHz bathymetry laser was 22.2 meters, and 

it was located along the western shoreline of Tatoosh Island. This was near the 

maximum range that the secchi readings, although collected the previous year, suggested 

could be achieved. 

DATA QUALITY ALONG EXPOSED AND UNEXPOSED COASTLINE 

During the planning phase, there was concern over the suitability of LIDAR for being 

used as a bathymetry acquisition tool along this particular stretch of coastline. The 

degree of exposure to open ocean conditions and prevailing swell direction can at times 

produce considerable surf breaks in this area, through which the bathymetry laser would 

not penetrate. Having the survey designed around Cape Flattery, it provided an 

opportunity to assess the impact of open ocean exposure on the ability to successfully

acquire ALB data in this area, as 6 km of relatively unexposed coastline exist 

immediately adjacent to roughly the same length of exposed coastline along the western 

edge of Cape Flattery (Figure 5). 

Visual examination of LIDAR coverage did not suggest better LIDAR performance 

along the exposed stretch of coastline as compared to that along the unexposed (Figure 

5). In fact when gridded at a 4 meter resolution, bathymetry data was obtained 

throughout 1.18 km2 of the proposed 3.5 km2

 of exposed coastline (33.7 percent), in 

comparison to 1.03 km2

 of the proposed 3.05 km2 (33.7 percent) of unexposed coastline 

along the Cape Flattery portion of the survey area. Furthermore, the deepest soundings 

obtained in the entire survey area (> 20m depth) were acquired along the exposed side of 

Tatoosh Island. 

The bathymetry data along both these particular stretches of coastline were acquired on 

April 19, 22 and 23, 2006. Archived wave statistics obtained from the NOAA National 

Data Buoy Center (NDBC) for Station 46087, located approximately 11 km north of 

Tatoosh Island (48°29'38" N, 124°43'38" W), indicated that relatively calm seas occurred 

in this area throughout the entire survey effort. The buoy data shows the general wave 

trend for this particular time frame consisted of swell heights being less than 1.75 meters 

on a greater than 10 second swell period and with wind waves being less than 0.75 meters 

spaced on an roughly 4 second wave period (Figure 6). In general, both swell and wind 

direction came directly from the west during the survey flights (Table 1). The degree of 

swell and wave conditions at the time of survey were mild enough to not negatively 

impact the ALB data along the exposed coastline any more than that along the unexposed 

coastline. This indicates that other factors such as increased turbidity from recent rainfall 

and floating kelp played a more significant role than exposure in impairing laser 

penetration along this particular stretch of coastline. 

7 
Figure 5. Adjacent stretches of exposed (purple) and unexposed (green) coastline within the 

proposed survey area. Achieved LIDAR bathymetry data are shown (black), with 10 meter 

bathymetry contour (blue). 

8 
Figure 6. Archived wave summary statistics from NDBC station 46087, April 19-26, 2005 (UTC).

SWHT = swell height, WWHT = wind wave height, SWPD = swell period, WWPD = wind wave 

period. 

Table 1. Archived wave summary statistics from NDBC station 46087, April 19-26, 2005 (UTC). SWDIR 

= swell direction, WWDIR = wind wave direction. Values are azimuth degrees. 

SWDIR WWDIR

Mean 272 265

Min 252 211

Max 294 357

9 
LIDAR AND MULTIBEAM DATA MERGE

Through a partnership between OCNMS, NOAA’s OCS and OMAO, high resolution 

bathymetry (HRB) was collected on various opportunistic occasions during the months of 

October from 2001 to 2004 aboard the NOAA ship RAINIER (Intelmann et al. 2006). 

Shallow water multibeam sounding data were cleaned according to NOAA standards 

(NOAA 2003), and were referenced to the MLLW tidal datum using the tide gauge at 

Neah Bay (Station 9443090) for datum control. 

DGPS in the ellipsoidal datum of NAD83 supplied both the positional information and 

project control for the LIDAR survey. In order to easily merge the data set with existing 

multibeam sounding data, survey instructions required the data to be projected during 

post-processing and delivered in the UTM Zone 10 projection. The Geoid99 height 

model was used to convert the vertical datum from the ellipsoidal 3-D datum of NAD83 

to the orthometric vertical datum NAVD88. In order to accurately merge the LIDAR 

data with existing multibeam sounding data, the data sets must be in the same vertical 

reference frame (Milbert 2002). Since the multibeam sounding data were referenced to 

an averaged tidally-derived vertical datum (MLLW) and the LIDAR data were referenced 

to an orthometric vertical datum (NAVD88) based on Mean Sea Level (MSL), a VDatum

model (Spargo et. al 2006) was needed to vertically transform the LIDAR data to MLLW

for compatibility and comparison with the multibeam sounding data. The VDatum model 

relates the NAVD88 to MLLW by using a grid or zone of tide model comparisons 

(Figure 7) with known leveled tide benchmark stations to better account for the spatial 

variability of tidal dynamics over a given area (Milbert 2002; Spargo et. al 2006). The 

VDatum model that was used is available for download at 

http://chartmaker.ncd.noaa.gov/csdl/vdatum_projectsWA.htm. 

Figure 7. VDatum tide modeling grid for the San Juan Islands, Strait of Juan de Fuca and

Puget Sound (Spargo et al. 2006). 

10 
Both the multibeam sounding and LIDAR xyz data were imported into Fledermaus using 

AVGGrid with 4 meter grid spacing (Figure 8), and then exported as separate ESRI 

floating-point ASCII grids for surface comparison. 

Figure 8. Multibeam sounding data combined with bathymetry and topographic LIDAR

data sets. Data are gridded at 4 meter resolution. Visible areas of the brown-dotted 

polygon are “holidays” in LIDAR acquisition due to poor water clarity. 10 m isobath is 

shown as the blue line. 

11 
The two ASCII grids were converted to polygon features and intersected in ARCInfo to

create a mask polygon. ARCInfo grid was then used to mask each of the ASCII grids 

with the intersect polygon, thus creating two new grids that were only populated with 

cells for which each data set had in common. The two new grids, which now contained 

only data common to both surfaces, were exported again as separate ASCII grid files and 

then imported back into Fledermaus using AVGGrid with 4 meter spacing. A difference 

DTM was created in Fledermaus by subtracting the LIDAR surface from the multibeam 

sounding surface to produce a new difference surface. The difference surface contained 

over 44,000 samples for which each grid had in common, with depth differences ranging 

from –24.3 to 8.48 meters, a mean difference of –0.967 and standard deviation of 1.762 

meters (Figure 9). Depth differences between the LIDAR and multibeam surfaces were

further compared to the acoustic multibeam data alone, assuming the acoustic soundings 

represent a more accurate reference benchmark surface (Riley 1995). As with Riley 

(1995), no attempt was made to assess individual error contribution to each data source. 

he extreme deviations observed in the least squares fit between the multibeam and 

le 

al

Figure 11 where the enhanced surface difference is readily distinguished by examining 

Figure 9. Depth difference histogram. The 2 * Std. Deviation (90 percentile) range is

highlighted in yellow. Depth difference in meters (Multibeam Surface – LIDAR Surface) is 

represented by the X-axis, and the Y-axis is the percentage of samples contained in each

difference bucket category. 

T

LIDAR surfaces are attributed to false bottom detections in the LIDAR depths due to

water column interference (Figure 10). When examining only the 90th percentile samp

range (-0.54–2.33 m depth difference), the multibeam sounding data are for the majority 

about 1 to 1.5 meters more shoal than the LIDAR data. This is not surprising since 

multibeam systems produce more dense data thus leading to delineation of more sho

features. This shoal bias of the multibeam data can be more easily visualized through

12 
Figure 10. Linear least squares data model between multibeam soundings and LIDAR depths

(m). LIDAR = -2.576+0.835*Multibeam sounding depth, R-Squared = 0.682. 

Figure 11. Multibeam and LIDAR xyz data merged into seamless DTM covering Makah Bay. 

Note the multibeam cross line is about 0.5 m more shoal than the LIDAR surface. Red line 

represents the location and extent of the bathymetry profile shown on the bottom. Purple 

contour is the 7 m bathymetry curve. 

13 
the cross line of multibeam data. The largest of the depth differences, those values in the 

xtreme tails of the histogram (red portion of the sample range in Figure 8), are traceable 

to two distinct areas and appear to be artifacts of errors in LIDAR data cleaning due to 

interference from false bottom detection (Figure 12). The remaining general surface 

difference trend could be attributed to the fact that the multibeam data are cleaned and 

gridded with a shoal biased constraint to be more conservative with respect to dangers to 

navigation. 

s with most coastal ALB surveys, floating kelp beds, breaking surf lines and turbid 

ater were challenges to this survey. The window of opportunity for capturing favorable 

nvironmental conditions to successfully acquire ALB in coastal areas, such as OCNMS, 

narrow. Avoiding the detrimental effects of turbid water created from excessively 

erated breaking surf and increased surface runoff from heavy spring rains require data 

cquisition to be targeted for late spring to early summer. However, kelp growth and 

e

Figure 12. An area of significant surface difference (red and orange pixels) attributed to improper 

cleaning of the LIDAR data resultant from surface interference. The white line shows extent and 

location of profile, which indicates an 8 meter surface difference at the western end of the line and submeter surface difference (green and blue pixels) throughout the remainder. 

DISCUSSION AND CONCLUSIONS 

A

w

e

is

a

a

increased biological productivity can further impede the rate of acquisition success in this

region beginning as early as May. Because of all these factors for attempting to acquire 

the LIDAR data for this particular survey, late April was selected. 

14 
The less than 2 meter swell and minimal wind-induced wave action that were 

experienced did not appear to negatively impact data quality over the course of the 

survey, indicating that ALB can successfully be achieved in this area at these particular 

a states. Although sea state was favorable for this time of the year, recent heavy 

infall and a persistent low-lying fog layer severely reduced the productivity of this 

survey. Additional project funds would have been helpful to keep the mobilized flight

crew on site while survey conditions continued to improve in order to maximize 

acquisition success. 

The existence of a completed VDatum model covering this geographic region permitted 

the LIDAR data to be seamlessly merged with shallow water multibeam data using the

same control datum. Of note, since OCNMS uses UTM coordinates to position all 

multibeam sounding data, it was required that the contractor deliver the NAVD88 

referenced z-values in that same coordinate system. Unfortunately, it was later 

determined that VDatum Version 1.06 only accepts geographic coordinates, thus the 

positional information delivered by FPI in UTM had to be unprojected back to latitude 

and longitude (decimal degrees) prior to transforming the vertical units. This was a very 

time consuming step, which in retrospect, could have been avoided by simply not 

requiring the contractor to project the data prior to transformation. The VDatum tool 

would benefit from a future enhancement to address this limitation. 

Despite relatively poor survey productivity resulting from poor flying conditions, a 

significant portion of nearshore bathymetry was acquired along the Cape Flattery 

coastline. The entire intertidal zone from Koitlah Point to Cape Alava, including 

n

uired

rvey methods. Due to a 

ck of project funds and a desire to cover as much area as possible, this survey was 

designed to acquire 4 by 4 m spot spacing bathymetry data with just 100 percent 

coverage. Even though coverage for

athymetric LIDAR acquisition at a 4 by 4 spot spacing, it is possible that the data could 

s

lity

autical charts.

this data

s in 

nd

se

ra

umerous offshore rocks and islands, was also better defined by the high-resolution 

pographic LIDAR elevation data. The bathymetry data that were successfully acq

ould potentially provide useful information for delineating rock features in many areas

at were too hazardous to access through ship-based acoustic su

to

c

th

la

NOAA’s OCS often requires 200 percent

b

still be used to update the Cape Flattery nautical chart 18485. Many of the least depth

recorded on that chart are rather dated with some soundings potentially being obtained as 

early as 1834 (NOAA 2002). But it is important to stress that this survey was not 

designed or performed for nautical charting purposes and several critical levels of qua

control were not implemented to evaluate and process the data for such purposes. 

Therefore the data will be submitted to NOAA’s Hydrographic Survey Division for 

outside-source evaluation and archival at the very least. Various other elements within 

the NOS Hydrographic Surveys Specifications and Deliverables (2003) will also need to

be assessed prior to electing the data for possible inclusion on the n

LIDAR technology continues to evolve at a rapid pace. In the short time since

was acquired, significant improvements have been made to the acquisition algorithm

order to increase extraction of more useful information for aiding environmental 

assessment (Francis and Tuell 2005). For example, in addition to acquiring depth a

15 
digital still frames, as with the SHOALS 1000T system used here, the new Compact 

Hydrographic Airborne Rapid Total Survey (CHARTS) system now has the ability to 

measure hyperspectral data, and it can produce seafloor reflectance images, as we

et al. in press). This n

ll (Tuell

ew system could be an extremely useful tool for the National 

arine Sanctuary Program (NMSP) by providing the ability to rapidly gain knowledge of 

he

BC wave statistics,

nd Kathy Dalton for manuscript edits. The paper further benefited from comments 

M

both coastal and nearshore topography, combined with water column characteristics and 

seafloor reflectance – all of which are important components for understanding changes

to the nearshore coastal and benthic environment. 

ACKNOWLEDGEMENTS 

The author would like to thank LCDR Richard Fletcher for assistance with obtaining t

secchi readings, Dr. Richard Bouchard for providing the archived ND

a

provided by Dave Sinson, Pacific Hydrographic Branch, Seattle, WA.

16 
REFERENCES 

Francis, K. and G. Tuell. 2005. Rapid environmental assessment: The next advancemen

in airborne bathymetric LIDAR. Ocean Ne

t

ws and Technology. May/June 2005.

telmann, S.S., J. Beaudoin, and G.R. Cochrane. 2006. Normalization and 

characterization of multibeam backscatter: Koitlah Point to Point of the Arches, 

Olympic Coast Nation MPR-115-2004-03. Marine

Sanctuaries Conservation Series MSD-06-03. U.S. Department of Commerce, 

National Oceanic and Atmospheric Administration, Marine Sanctuaries Division, 

ry.

Milbert, D.G. 2002: Documentation for VDatum and a Datum tutorial. Vertical datum 

transformation software, Version 1.06. 23 pp. 

MOA. 1998. Memorandum of Agreement between the U.S. Army Engineers 

(USACE) and the Naval Meteorology and Oceanography Command 

(COMNAVMETOCCOM) to establish the Joint Airborne LIDAR Bathymetry 

Technical Center of Expertise. 

MOA. 2002. A Memorandum of Understanding Among the U.S. Army Engineer South 

Atlantic Division and the U.S. Army Engineer Research and Development Center 

and the Naval Meteorology and Oceanography Command and the National 

Oceanic Administration through the National Ocean Service and the Office of 

Marine and Aviation Operations to establish the Joint Airborne LIDAR 

Bathymetry Technical Center of Expertise. MOA-2002-047. 6pp. 

National Research Council. 2004. A Geospatial Framework for the Coastal Zone, 

National Needs for Coastal Mapping and Charting. Committee on National Needs 

for Coastal Mapping and Charting. National Research Council of the National 

Academies. The National Academies Press. Washington, D.C. 168 pp. 

NOAA. 2003. NOS Hydrographic Surveys Specifications and Deliverables. March 

2003. 150pp. http://nauticalcharts.noaa.gov/hsd/specs/specs.htm. 

NOAA. 2002. Nautical chart 15485. 15th Edition. December 2002. Marine Chart 

Division N/CS2, National Ocean Service, NOAA, Silver Spring, Maryland. 

Riley, J.L. 1995. Evaluating SHOALS bathymetry using NOAA hydrographic survey 

data. 24th Annual Joint Meeting of UJNR Sea-Bottom Survey Panel. Nov 13-17, 

1995, Tokyo, Japan. 10pp. 

Spargo, E. A., Hess, K. W., White S. A., 2006. VDatum for the San Juan Islands and 

In

al Marine Sanctuary - Survey H

Silver Spring, MD. 22pp. 

MacDonald, A. 2005. New developments increase use of airborne LIDAR bathymet

SeaTechnology. September 2005. 46-48. 

17 
Strait of Juan de Fuca with Sound: Tidal Datum Modeling and 

Population of the Grids. U.S. Department of Commerce, National Oceanic and 

Kopilevich.

ydrographic & Topographic LIDAR Acquisition, Northwest Coast, Washington, Neah 

Updates for Puget

Atmospheric Administration, Silver Spring, Maryland, NOAA Technical Report, 

NOS CS 23. (In review). 

Tuell, G. J.Y. Park, J. Aitken, V. Ramnath, V. Feygels, G. Guenther, and Y.

SHOALS-enabled 3-d benthic mapping, Proc. SPIE Vol. 5806. Algorithms and 

Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XI. S. 

Chen and P. Lewis Eds. In press. 

APPENDIX 

H

Bay to Cape Alava, WA Survey Report.

18 
ONMS CONSERVATION SERIES PUBLICATIONS 

To date, the following reports have been published in the Marine Sanctuaries 

Conservation Series. All publications are available on the Office of National Marine 

Sanctuaries website (http://www.sanctuaries.noaa.gov/). 

Con

Acc

Nor eam Backscatter: Koitlah Point to Point of the Arches, 

Oly pic Coast National Marine Sanctuary (ONMS-06-03)

Dev oping Alternatives for Optimal Representation of Seafloor Habitats and Associated Communities

in Stellwagen Bank National Marine San -02) 

Benthic Habitat Mapping in the Olympic Coast National Marine Sanctuary (ONMS-06-01) 

Movement of yellowtail snapper (Ocyurus chrysurus Block 1790) and black grouper 

(Mycteroperca bonaci Poey 1860) in the northern Florida Keys National Marine Sanctuary as 

determined by acoustic telemetry (MSD-05-4) 

The Impacts of Coastal Protection Structures in California's Monterey Bay National Marine 

Sanctuary (MSD-05-3) 

An annotated bibliography of diet studies of fish of the southeast United States and Gray's Reef 

National Marine Sanctuary (MSD-05-2) 

Noise Levels and Sources in the Stellwagen Bank National Marine Sanctuary and the St.

Lawrence River Estuary (MSD-05-1) 

Biogeographic Analysis of the Tortugas Ecological Reserve (MSD-04-1) 

A Review of the Ecological Effectiveness of Subtidal Marine Reserves in Central California

(MSD-04-2, MSD-04-3) 

Pre-Construction Coral Survey of the M/V Wellwood Grounding Site (MSD-03-1) 

Olympic Coast National Marine Sanctuary: Proceedings of the 1998 Research Workshop, Seattle, 

Washington (MSD-01-04) 

Workshop on Marine Mammal Research & Monitoring in the National Marine Sanctuaries (MSD01-03) 

A Review of Marine Zones in the Monterey Bay National Marine Sanctuary (MSD-01-2) 

Distribution and Sighting Frequency of Reef Fishes in the Florida Keys National Marine 

Sanctuary (MSD-01-1) 

Flower Garden Banks National Marine Sanctuary: A Rapid Assessment of Coral, Fish, and Algae 

Using the AGRRA Protocol (MSD-00-3) 

The Economic Contribution of Whale watching to Regional Economies: Perspectives From Two 

National Marine Sanctuaries (MSD-00-2) 

Olympic Coast National Marine Sanctuary Area to be Avoided Education and Monitoring

Program (MSD-00-1) 

Multi-species and Multi-interest Management: an Ecosystem Approach to Market Squid (Loligo

opalescens) Harvest in California (MSD-99-1)

servation Science in NOAA's National Marine Sanctuaries: Description and Recent

omplishments (ONMS-06-04) 

malization and Characterization of Multib

m

el

ctuary (ONMS-06

Channel Islands Deep Water Monitoring Plan Development Workshop Report (ONMS-05-05)