**Balloon-Borne Sounding System (BBSS) Handbook**

R. Coulter\
D. Hodlridge\
M. Ritsche

January 2009

Work supported by the U.S. Department of Energy,

Office of Science, Office of Biological and Environmental Research

**DISCLAIMER**

This report was prepared as an account of work sponsored by the U.S.
Government. Neither the United States nor any agency thereof, nor any of
their employees, makes any warranty, express or implied, or assumes any
legal liability or responsibility for the accuracy, completeness, or
usefulness of any information, apparatus, product, or process disclosed,
or represents that its use would not infringe privately owned rights.
Reference herein to any specific commercial product, process, or service
by trade name, trademark, manufacturer, or otherwise, does not
necessarily constitute or imply its endorsement, recommendation, or
favoring by the U.S. Government or any agency thereof. The views and
opinions of authors expressed herein do not necessarily state or reflect
those of the U.S. Government or any agency thereof.

Contents

[1. General Overview 1](#general-overview)

[2. Contacts 1](#contacts)

[2.1 Mentors 1](#mentors)

[2.2 Instrument Developer 1](#instrument-developer)

[3. Deployment Locations, History, and Significant Events
2](#__RefHeading___Toc220912851)

[4. Near-Real-Time Data Plots 6](#near-real-time-data-plots)

[5. Data Description and Examples 6](#data-description-and-examples)

[5.1 Data File Contents 6](#data-file-contents)

[5.1.1 Primary Variables and Expected Uncertainty
7](#primary-variables-and-expected-uncertainty)

[5.1.2 Secondary/Underlying Variables 8](#secondaryunderlying-variables)

[5.1.3 Diagnostic Variables 8](#diagnostic-variables)

[5.1.4 Data Quality Flags 8](#data-quality-flags)

[5.1.5 Dimension Variables 9](#dimension-variables)

[5.2 Annotated Examples 9](#annotated-examples)

[5.3 User Notes and Known Problems 9](#user-notes-and-known-problems)

[5.4 Frequently Asked Questions 11](#frequently-asked-questions)

[6. Data Quality 15](#data-quality)

[6.1 Data Quality Health and Status 15](#data-quality-health-and-status)

[6.2 Data Reviews by Instrument Mentor
16](#data-reviews-by-instrument-mentor)

[6.3 Data Assessments by Site Scientist/Data Quality Office
17](#data-assessments-by-site-scientistdata-quality-office)

[6.4 Value-Added Procedures and Quality Measurement Experiments
18](#value-added-procedures-and-quality-measurement-experiments)

[7. Instrument Details 19](#instrument-details)

[7.1 Detailed Description 19](#detailed-description)

[7.1.1 List of Components 19](#list-of-components)

[7.1.2 System Configuration and Measurement Methods
20](#system-configuration-and-measurement-methods)

[7.1.3 Specifications 21](#specifications)

[7.2 Theory of Operation 22](#theory-of-operation)

[7.3 Calibration 22](#calibration)

[7.3.1 Calibration Theory 22](#calibration-theory)

[7.3.2 Calibration Procedures 22](#calibration-procedures)

[7.3.3 Calibration History 22](#calibration-history)

[7.4 Operation and Maintenance 22](#operation-and-maintenance)

[7.4.1 User Manual 22](#user-manual)

[7.4.2 Routine and Corrective Maintenance Documentation
22](#routine-and-corrective-maintenance-documentation)

[7.4.3 Software Documentation 22](#software-documentation)

[7.4.4 Additional Documentation 22](#additional-documentation)

[7.5 Glossary 23](#glossary)

[7.6 Acronyms 23](#acronyms)

[8. Citable References 23](#citable-references)

[8.1 Bibliography 23](#bibliography)

Figures

[1 Sample comparisons of sounding profiles
17](#__RefHeading___Toc220912887)

[2 Sample sonde diagnostic plots 18](#__RefHeading___Toc220912888)

Tables

[1 ACRF-owned Vaisala radiosonde ground stations
5](#__RefHeading___Toc220912889)

[2 Summary of data files created by ARM Vaisala ground stations
6](#__RefHeading___Toc220912890)

[3 Technical specifications and manufacturer's stated uncertainty for
the meteorological sensors used in radiosondes employed by the ARM
Program 8](#__RefHeading___Toc220912891)

[4 Data quality min/max limits 8](#__RefHeading___Toc220912892)

# General Overview

The balloon-borne sounding system (BBSS) provides in situ measurements
(vertical profiles) of both the thermodynamic state of the atmosphere
and the wind speed and direction.

# Contacts

## Mentors

Rich Coulter (Lead Mentor)\
Argonne National Laboratory\
9700 South Cass Avenue\
Argonne, Illinois 60439\
Phone: (630) 252-5833\
Fax: (630) 252-2959\
e-mail: <rlcoulter@anl.gov>

Michael T. Ritsche (assistant mentor, hardware and field support)

Environmental Science Division

Argonne National Laboratory

9700 South Cass Avenue

Argonne, Illinois 60439

Phone: (630) 252-1554

Fax: (630) 252-2959

e-mail: <mtritsche@anl.gov>

Donna J. Holdrige (assistant mentor, documentation, software, and
quality assurance)

Environmental Science Division

Argonne National Laboratory

9700 South Cass Avenue

Argonne, Illinois 60439

Phone: (630) 252-5148

Fax: (630) 252-2959

e-mail: <djholdridge@anl.gov>

## Instrument Developer

Vaisala, Inc. (North America Support Office)\
10-D Gill Street\
Woburn, Massachusetts 01801\
Tel: (781) 933 4500

Toll-free: (888) 824-7252\
Fax: (781) 933-8029

e-mail: [www.vaisala.com](http://www.vaisala.com/)

# Deployment Locations, History, and Significant Events 

At the North Slope of Alaska (NSA) locale[^1]--

-   Barrow, (Great White, C1) 71.32N, 156.62W, 27 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-III s/n W03202* (April 24, 2002 --
    present)

-   *Atmospheric infrared sounder (AIRS) validation IOP system: pcCORA*
    (July 22, 2002 -- present)

-   *Spare system: digiCORA-II s/n R41204* (August 15, 2004 -- present)

-   *Production system: National Oceanic and Atmospheric Administration
    (NOAA)/Cross-chain Loran Atmospheric Sounding System (CLASS)* (May
    20, 1998 -- May 4, 2002)

-   Updated digiCORA-III to v3.12 (July 3, 2005)

-   Updated digiCORA-III to v3.51 September 19, 2006

-   Increased reported precision of RH from 1.0% to 0.1% (September 29,
    2006)

-   Updated digiCORA-III to v3.52 January 30, 2007

At the Tropical Western Pacific (TWP) locale--

-   Manus Island, PNG (C1) 2.06S, 147.43E, 4 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-III (MW-31) s/n B31401*

-   Assigned WMO station identifier (044 block 92)

-   Installed Synergetics DCP 07/2000

-   Replaced old production system (s/n T32102) with digiCORA-III v3.52
    June 16, 2007

-   Increased reported precision of RH from 1.0% to 0.1% (June 16, 2007)

```{=html}
<!-- -->
```
-   Republic of Nauru (C2) 0.52S, 166.92E, 7 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-III (MW-31) s/n B131402*

-   Assigned WMO station identifier (532 block 91)

-   Installed Synergetics DCP 07/2000

-   Replaced old production system (s/n S35304) with digiCORA-III v3.52
    August 18, 2007

-   Increased reported precision of RH from 1.0% to 0.1% (August 18,
    2007)

```{=html}
<!-- -->
```
-   Darwin, Australia (C3)[^2] 12.42S, 130.88E, 30 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-III (June 7, 2004 -- present)*

-   *Production system: pcCORA (February 1, 2002? -- June 6, 2004)*

-   WMO station identifier (120 block 94)

-   Operated by Australian Bureau of Meteorology (BOM)

At the Southern Great Plains (SGP) site--

-   Central Facility (CF) (C1) 36.61N, 97.49W, 315 m

```{=html}
<!-- -->
```
-   *Production system: pcCORA* (May 27, 1992 -- April 12, 1999*)*

-   *Production system: digiCORA-II s/n R48501* (April 13, 1999 -- July
    31, 2002)

-   *Production system: digiCORA-III s/n W09201* (August 1, 2002 --
    present)

-   *AIRS validation IOP system (S01): digiCORA-I s/n 574791*

-   *AIRS validation IOP system (S02): digiCORA-I s/n 708515*

-   System installed May 27, 1992

-   Started regular (19:30) soundings July 14, 1992

-   Started ground checks January 21, 1993

-   Changed to high resolution sampling (2-sec) May 20, 1993

-   Installed RESEARCH software March 30, 1994

-   Started RESEARCH mode soundings April 7, 1994

-   Stopped RESEARCH mode soundings May 21, 1994

-   Stopped ground checks August 3, 1994

-   Installed RAWDATA software November 15, 1994

-   Assigned WMO station identifier (646 block 74) August 19, 1996

-   Software upgrade to generate WMO-coded messages for NWS March 24,
    1997

-   Installed MW-15 digiCORA-II September 1, 1997 for WVIOP

-   Changed regular sounding schedule from 5 per day to 3 per day
    November 14, 1997

-   Added 0530 Universal Time Coordinates (UTC) sounding to regular
    schedule (1130, 2030, 2330) November 30, 1998

-   Updated PC-CORA and digiCORA-II and MF-12 for Y2K June 9, 1999

-   Stopped RESEARCH mode for winds November 24, 2000

-   Began operational use of RS-90 radiosondes May 1, 2001

-   Changed sounding schedule to 0530, 1130, 1730, 2330 August 1, 2001

-   Transferred PC-CORA to NSA June 24, 2002

-   Began digiCORA-III (MW-21) transition IOP July 10, 2002

-   Updated digiCORA-III to v3.12 and RB-21 antenna July 27, 2005

-   Updated digiCORA-III to v3.51 September 19, 2006.

-   Increased reported precision of RH from 1.0% to 0.1% (September 29,
    2006)

-   Updated digiCORA-III to v3.52 January 30, 2007

```{=html}
<!-- -->
```
-   Hillsboro, Kansas (boundary facility \[BF\]1) 38.30N, 97.30W, 447 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-I s/n 530483 (January 18, 1994 --
    November 22, 1997)*

-   Installed January 18, 1994

-   Started RESEARCH mode soundings April 7, 1994

-   Stopped RESEARCH mode soundings May 21, 1994

-   Installed directional antenna March 28, 1996

-   Assigned WMO station identifier (547 block 74) August 19, 1996

-   Started automatic generation of WMO-coded messages October 28, 1996

-   Added global positioning system (GPS) windfinding capability March
    25, 1997

-   Suspended daily soundings at all BFs November 22, 1997

-   Updated digiCORA and MF-12 for Y2K June 11, 1999

-   Stopped RESEARCH mode for winds November 24, 2000

-   Updated digiCORA and RB-21 for RS92 July 27, 2005

```{=html}
<!-- -->
```
-   Vici, Oklahoma (BF4) 36.07N, 99.20W, 622 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-I s/n 574791* (January 18, 1994 --
    November 22, 1997)

-   Installed January 18, 1994

-   Started RESEARCH mode soundings April 7, 1994

-   Stopped RESEARCH mode soundings May 21, 1994

-   Installed directional antenna August 1, 1996

-   Assigned WMO station identifier (641 block 74) August 19, 1996

-   Started automatic generation of WMO-coded messages October 28, 1996

-   Added GPS windfinding capability March 26, 1997

-   Suspended daily soundings at all BFs November 22, 1997

-   Updated digiCORA and MF-12 for Y2K June 11, 1999

-   Stopped RESEARCH mode for winds November 24, 2000

-   Updated digiCORA and RB-21 for RS92 July 27, 2005

```{=html}
<!-- -->
```
-   Morris, Oklahoma (BF5) 35.68N, 95.85W, 217 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-I s/n 574792* (January 18, 1994 --
    November 22, 1997)

-   Installed January 18, 1994

-   Started RESEARCH mode soundings April 7, 1994

-   Stopped RESEARCH mode soundings May 21, 1994

-   Assigned WMO station identifier (650 block 74) August 19, 1996

-   Started automatic generation of WMO-coded messages October 28, 1996

-   Added GPS windfinding capability March 27, 1997

-   Suspended daily soundings at all BFs November 22, 1997

-   Updated digiCORA and MF-12 for Y2K June 11, 1999

-   Stopped RESEARCH mode for winds November 24, 2000

-   Updated digiCORA and RB-21 for RS92

```{=html}
<!-- -->
```
-   Purcell, Oklahoma (BF6) 34.97N, 97.42W, 344 m

```{=html}
<!-- -->
```
-   *Production system: digiCORA-I s/n 708515* (October 13, 1994 --
    November 22, 1997)

-   Installed October 13, 1994

-   Removed borrowed directional antenna February 17, 1995

-   Installed new directional antenna October 2, 1995

-   Assigned WMO station identifier (651 block 74) August 19, 1996

-   Started automatic generation of WMO-coded messages October 31, 1996

-   Added GPS windfinding capability March 25, 1997

-   Suspend daily soundings at all BFs November 22, 1997

-   Updated digiCORA and MF-12 for Y2K June 11, 1999

-   Stopped RESEARCH mode for winds November 24, 2000

-   Updated digiCORA and RB-21 for RS92 July 27, 2005

Table 1 shows the general attributes of each of the Atmospheric
Radiation Measurement (ARM) Climate Research Facility (ACRF)-owned
Vaisala ground stations as well as providing a guide to their deployment
history during intensive operational periods (IOPs). The IOP
designations at the bottom of the table refer to the facility
identification code used in the standard ARM data file naming
convention. For example, data produced during the AIRS IOP by the MW-11
serial number 574791 (normally assigned to SGP/B4) are named
sgpsondewnpnS01.b1.YYYYMMDD.HHMMSS.cdf.

[]{#__RefHeading___Toc220912889 .anchor}Table 1. ACRF-owned Vaisala
radiosonde ground stations

  ------------ ---------------- ----------- --------- ----------- ----------------- ----------- ----------- ------------ ------------------ -------- -------- -------- --------
               **Common Name**                                                                                                                                         

               **digiCORA-I**                                     **digiCORA-II**                                        **digiCORA-III**                              

  Model        MW-11            MW-11       MW-11     MW-11       MW-15             MW-15       MW-15       MW-15        MW-21              MW-21    MW-21    MW-31    MW-31

  S/N          530483           574791      574792    708515      T32102            S35304      S17401      R41204       W09201             W03202   Z15101   B31401   B31402

  Base         SGP/B1           SGP/B4      SGP/B5    SGP/B6      AMF/M1            SGP/spare   SGP/spare   SGP/spare    SGP/C1             NSA/C1   AMF/M1   TWP/C1   TWP/C2
  Location                                                                                                                                                             

  Current      SGP/IOP          SGP/spare   SGP/IOP   SGP/spare   SGP/C1            SGP/C1      SGP/C1      NSA/C1/GW)   SGP/C1             NSA/C1   AMF/M1   TWP/C1   TWP/C2
  Location                                                                                                                                                             

  Loran        YES              YES         YES       YES         YES               YES         YES         YES          YES                YES      YES      NO       NO
  equipped                                                                                                                                                             

  GPS equipped YES              YES         YES       YES         YES               YES         YES         YES          YES                YES      YES      YES      YES

  RS08-H       YES              YES         YES       YES         YES               YES         YES         YES          YES                YES      YES      YES      YES
  compatible                                                                                                                                                           

  RS90         YES              YES         YES       YES         YES               YES         YES         YES          YES                YES      YES      YES      YES
  compatible                                                                                                                                                           

  RS92         YES              YES         YES       YES         YES               YES         YES         YES          YES                YES      YES      YES      YES
  compatible                                                                                                                                                           

  Software     8.35             8.35        8.35      8.35        8.35              8.35        8.35        8.34         3.52               3.52     3.52     3.52     3.52
  version                                                                                                                                                              

  IOP Name                                                                                                                                                             
  (site)                                                                                                                                                               

  AIRS (I-V)                    SGP/S01               SGP/S02                       TWP/C2                               NSA/C1                                        

  AWEX-G (SGP) SGP/S03          SGP/S01     SGP/S04   SGP/S02                                               SGP/S05                         SGP/C1                     

  AWWVIOP                                                                                                                NSA/C1 (D[^3])                                
  (NSA)                                                                                                                                                                

  BLCE (NSA)                                                                                                             NSA/C1 (GW)                                   

  MPACE (NSA)                               NSA/S02                                                         NSA/C2       NSA/C1 (D)                                    

  Point Reyes                                                                                                                                        PYE/M1            

  Niamey                                                                                                                                             NIM/M1            

  Black Forest                                                                                                                                       FKB/M1            

  CLASIC (SGP) SGP/B4           SGP/B1      SGP/B5    SGP/S06                                                                                                          

  AIRS/IASI                                 SGP/S01   SGP/S02                                               NSA/S01      NSA/C1                                        
  ------------ ---------------- ----------- --------- ----------- ----------------- ----------- ----------- ------------ ------------------ -------- -------- -------- --------

# Near-Real-Time Data Plots

Quicklooks are plots of collected data, of varying sophistication. Plots
of ARM sounding data from all sites may be accessed by using the [DQ
HandS](http://dq.arm.gov/) (Data Quality Health and Status) system.
Click on the site of interest and choose the radiosonde
(SSSsondewnpn.b1) link.

# Data Description and Examples

## Data File Contents

With the exception of the early NSA data described in Section 5.3, the
netCDF ARM radiosonde data files distributed by the ARM Archive are
identical to one another regardless of site or ground station of origin.
Some of the raw data files produced by the different ground station
types are unique, however, and although most users will have no need or
interest in accessing these files, they are archived and available by
special request. The instrument-created data files are listed in Table
2; examples of the ASCII files are available through the links provided
in Section 5.2.

[]{#__RefHeading___Toc220912890 .anchor}Table 2. Summary of data files
created by ARM Vaisala ground stations

+---------------------+-----------------------+-----------------------+
| **Radiosonde        | **Filename**          | **Description**       |
| System**            |                       |                       |
+---------------------+-----------------------+-----------------------+
| pcCORA              | PRT.CUR               | Standard ASCII output |
|                     |                       | with processed data:  |
| All files are       | RAWDATA.CUR           | this file is passed   |
| created and stored  |                       | to the ingest module  |
| on the local        | EDITED.CUR            | to create the netCDF  |
| instrument computer |                       | files distributed by  |
| and transmitted to  |                       | the archive           |
| the site data       |                       |                       |
| system when the     |                       | Binary raw            |
| sounding is         |                       | thermodynamic data    |
| completed. The      |                       | directly from the     |
| local files are     |                       | radiosonde            |
| renamed after       |                       |                       |
| transfer.           |                       | Binary copy of        |
|                     |                       | processed             |
|                     |                       | thermodynamic and     |
|                     |                       | wind data             |
+---------------------+-----------------------+-----------------------+
| MW-11 and MW-15     | PRT.CUR               | Standard ASCII output |
| (digiCORA-I and     |                       | with processed data:  |
| -II)                | MPPPTU.RAW            | this file is passed   |
|                     |                       | to the ingest module  |
| The standard ASCII  | LORANC.EDT            | to create the netCDF  |
| data istransmitted  |                       | files distributed by  |
| by a serial         | LORANC.PAR            | the archive           |
| connection in       |                       |                       |
| real-time to the    | LORANC.DER            | As defined above      |
| site data system    |                       |                       |
| where it is         | LORANC.PHA            | Binary copy of        |
| collected in an     |                       | processed             |
| ASCII file.         | GPSWND.RAW            | thermodynamic and     |
|                     |                       | wind data             |
| At the SGP and NSA, |                       |                       |
| these files are     |                       | Binary position       |
| recorded on floppy  |                       | derivative data       |
| disk for each       |                       |                       |
| sounding and not    |                       | Binary raw Loran      |
| usually archived;   |                       | phase data            |
| at the TWP they are |                       |                       |
| recorded on hard    |                       | Binary raw GPS wind   |
| disk, bundled, and  |                       | data                  |
| sent to the         |                       |                       |
| archive.            |                       |                       |
|                     |                       |                       |
| Note that raw files |                       |                       |
| associated with GPS |                       |                       |
| radiosondes will be |                       |                       |
| named "GPSSND.xxx"  |                       |                       |
| rather than         |                       |                       |
| "LORANC.xxx."       |                       |                       |
+---------------------+-----------------------+-----------------------+

Table 2. (contd)

+---------------------+-----------------------+-----------------------+
| **Radiosonde        | **Filename**          | **Description**       |
| System**            |                       |                       |
+---------------------+-----------------------+-----------------------+
| MW-21               | SSSsonder             | Standard ASCII output |
| (digiCORA-III)      | awFF.YYYYMMDDHHMM.raw | with processed data:  |
|                     |                       | this file is passed   |
| All files are       | SSSson                | to the ingest module  |
| created and stored  | deFF.YYYYMMDDHHMM.ptu | to create the netCDF  |
| on the local        |                       | files distributed by  |
| instrument computer | SSSsondeFF.           | the archive           |
| and collected by    | YYYYMMDD_HHMMSS.dc3db |                       |
| the site data       |                       | ASCII file with raw   |
| system when the     |                       | thermodynamic data    |
| sounding is         |                       | directly from the     |
| completed.          |                       | radiosonde            |
|                     |                       |                       |
|                     |                       | Binary sounding       |
|                     |                       | database file         |
+---------------------+-----------------------+-----------------------+

### Primary Variables and Expected Uncertainty

The following quantities are measured as functions of time during a
free-balloon ascent:

-   Pressure (hPa) netCDF name = "pres"

-   Temperature (°C) netCDF name = "tdry"

-   Relative Humidity (%RH) netCDF name = "rh"

-   Wind speed (m/s) netCDF name = "wspd"

-   Wind direction (deg) netCDF name = "dir"

Secondary (derived) quantities included in the data stream, also
measured as functions of time, are:

-   Altitude (gpm) netCDF name = "alt"

-   Dew Point (°C) netCDF name = "dp"

-   Ascent Rate (m/s) netCDF name = "alt"

-   Latitude of Sonde (°N) netCDF name = "lat"

-   Longitude of Sonde (°W) netCDF name = "lon"

-   u-component of wind velocity (m/s) netCDF name = "u_wind"

-   v-component of wind velocity (m/s) netCDF name = "v_wind"

#### Definition of Uncertainty

The manufacturer defines the cumulative sensor uncertainty at the
2-sigma (95.5%) confidence level. The uncertainty includes the following
factors:

-   Repeatability

-   Long-term stability

-   Measurement conditions

-   Dynamic effects (e.g. time lag)

-   Electronic effects

Repeatability is estimated from the standard deviation of differences
between two successive repeated calibrations (2-sigma). Reproducibility
is estimated from the standard deviation of differences in twin
soundings.

The manufacturer's specifications and stated uncertainty values for the
thermodynamic sensors in each radiosonde type used by ARM are presented
in Table 3.

[]{#__RefHeading___Toc220912891 .anchor}Table 3. Technical
specifications and manufacturer's stated uncertainty for the
meteorological sensors used in radiosondes employed by the ARM Program

+---------+--------+----------+---------+--------+----------+---------+
|         | **RS   |          |         | *      |          |         |
|         | -80H** |          |         | *RS-90 |          |         |
|         |        |          |         | and    |          |         |
|         |        |          |         | RS-92  |          |         |
|         |        |          |         | all    |          |         |
|         |        |          |         | t      |          |         |
|         |        |          |         | ypes** |          |         |
+---------+--------+----------+---------+--------+----------+---------+
|         | **Pres | **Tempe  | **Hum   | **Pres | **Tempe  | **Hum   |
|         | sure** | rature** | idity** | sure** | rature** | idity** |
+---------+--------+----------+---------+--------+----------+---------+
| Range   | 1060   | -90 to   | 0 to    | 1080   | -90 to   | 0 to    |
|         | to 3   | +60°C    | 100%RH  | to 3   | +60°C    | 100 %RH |
|         | hPa    |          |         | hPa    |          |         |
+---------+--------+----------+---------+--------+----------+---------+
| Res     | 0.1    | 0.1°C    | 1%RH    | 0.1    | 0.1°C    | 1       |
| olution | hPa    |          |         | hPa    |          | %RH^\*^ |
+---------+--------+----------+---------+--------+----------+---------+
| R       | n/a    | \<2.5 s  | 1 s (at | n/a    | 0.4 s    | \<0.5 s |
| esponse |        |          | s       |        | (1000    | (20°C)  |
| Time    |        |          | urface) |        | hPa)     |         |
|         |        |          |         |        |          | \<20 s  |
|         |        |          |         |        | 2.5 s    | (-40°C) |
|         |        |          |         |        | (10 hPa) |         |
+---------+--------+----------+---------+--------+----------+---------+
| Repeat  | 0.5    | 0.2°C    | 2%RH    |        | 0.15°C   | 2%RH    |
| ability | hPa    |          |         |        |          |         |
+---------+--------+----------+---------+--------+----------+---------+
| R       | 0.5    | 0.2°C \> | 3%RH    |        | 0.2°C \> | 3%RH    |
| eproduc | hPa    | 50 hPa   |         |        | 100 hPa  |         |
| ibility |        |          |         |        |          |         |
|         |        | 0.3°C \> |         |        | 0.3°C \< |         |
|         |        | 15 hPa   |         |        | 20 hPa   |         |
|         |        |          |         |        |          |         |
|         |        | 0.4°C \< |         |        |          |         |
|         |        | 15 hPa   |         |        |          |         |
+---------+--------+----------+---------+--------+----------+---------+
| Unce    | n/a    | n/a      | n/a     | n/a    | 0.5°C    | 5%RH    |
| rtainty |        |          |         |        |          |         |
+---------+--------+----------+---------+--------+----------+---------+
| ^\*^    |        |          |         |        |          |         |
| Nominal |        |          |         |        |          |         |
| res     |        |          |         |        |          |         |
| olution |        |          |         |        |          |         |
| value   |        |          |         |        |          |         |
| -- data |        |          |         |        |          |         |
| co      |        |          |         |        |          |         |
| llected |        |          |         |        |          |         |
| using   |        |          |         |        |          |         |
| digiC   |        |          |         |        |          |         |
| ORA-III |        |          |         |        |          |         |
| ground  |        |          |         |        |          |         |
| station |        |          |         |        |          |         |
| may be  |        |          |         |        |          |         |
| r       |        |          |         |        |          |         |
| eported |        |          |         |        |          |         |
| with    |        |          |         |        |          |         |
| higher  |        |          |         |        |          |         |
| pre     |        |          |         |        |          |         |
| cision. |        |          |         |        |          |         |
+---------+--------+----------+---------+--------+----------+---------+

### Secondary/Underlying Variables

This section is not applicable to this instrument.

### Diagnostic Variables

This section is not applicable to this instrument.

### Data Quality Flags

Some automated data quality checks are included in the processed BBSS
netCDF file. Checks now used are based on predefined limits for maximum,
minimum, and sample-to-sample change (delta) values of each raw
variable. The limits used for BBSS are shown in Table 4.

[]{#__RefHeading___Toc220912892 .anchor}Table 4. Data quality min/max
limits

  ---------- ------------- ------- --------- --------- ----------- --------- --------- ----------- --------- --------- -----------
  Variable   Name          Units   SGP                             TWP                             NSA                 

                                   **Min**   **Max**   **Delta**   **Min**   **Max**   **Delta**   **Min**   **Max**   **Delta**

  pres       pressure      hPa     0.0       1100.0    10.0        0.0       1100.0    10.0        0.0       1100.0    50.0

  tdry       dry bulb      C       -80.0     50.0      10.0        -80.0     50.0      10.0        -80.0     50.0      50.0
             temperature                                                                                               

  dp         dewpoint      C       -110.0    50.0      \-\-\--     -110.0    50.0      \-\-\--     -110.0    50.0      50.0
             temperature                                                                                               

  wspd       wind speed    m/s     0.0       75.0      \-\-\--     0.0       75.0      \-\-\--     \-\-\--   \-\-\--   \-\-\--

  deg        wind          deg     0.0       360.0     \-\-\--     0.0       360.0     \-\-\--     \-\-\--   \-\-\--   \-\-\--
             direction                                                                                                 

  rh         relative      pct     0.0       100.0     \-\-\--     0.0       100.0     \-\-\--     0.0       100.0     \-\-\--
             humidity                                                                                                  

  u_wind     eastward wind m/s     -100.0    100.0     \-\-\--     -100.0    100.0     \-\-\--     \-\-\--   \-\-\--   \-\-\--
             component                                                                                                 

  v_wind     northward     m/s     -100.0    100.0     \-\-\--     -100.0    100.0     \-\-\--     \-\-\--   \-\-\--   \-\-\--
             wind                                                                                                      
             component                                                                                                 

  wstat      wind status   none    0.0       \-\-\--   \-\-\--     0.0       \-\-\--   \-\-\--     \-\-\--   \-\-\--   \-\-\--

  asc        ascent rate   m/s     -10.0     20.0      5.0         -10.0     20.0      5.0         -10.0     20.0      5.0
  ---------- ------------- ------- --------- --------- ----------- --------- --------- ----------- --------- --------- -----------

An example BBSS file header (Data Object Design), which contains
information on BBSS automated QC, may be found for the ARM Mobile
Facility (AMF), NSA, SGP, and TWP at
[SONDE](http://science.arm.gov/tool/dod/showdod.php?Inst=sonde) (once
there, click on "sondewnpn.b1_new") and for the older NSA data at
[ISSSONDE](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/isssondeexamplehdr.txt)
(once there, click on "isssonde10s.a1_new").

### Dimension Variables

All profile data are one-dimensional arrays in time.

## Annotated Examples

Examples of ASCII files produced by ARM Vaisala ground stations.

-   Standard output file (PRT.CUR and
    [SSSsonderawFF.YYYYMMDDhhmmss.raw](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/akbsonde-curC1.20050704.1823.raw))

-   Raw thermodynamic data file[^4]
    ([SSSsondeFF.YYYYMMDDhhmmss.ptu](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/akbsondeptuC1.200507041755.ptu))

## User Notes and Known Problems

**Soundings at the North Slope of Alaska**

The BBSS system originally located at Barrow was an old CLASS-type that
was originally operated by NOAA's Climate Measurements and Diagnostics
Laboratory on TWP's Manus site. The early (May 20, 1998 -- May 4, 2002)
NSA radiosonde filenames (e.g., nsaisssonde10sC1.LL.YYYYMMDD.HHMMSS)
reflect this provenance. The "iss" refers to the integrated sounding
system of which this unit was once a part and the "10s" refers to the
fact that each sample in the output file is calculated from a 10-second
window of the raw (\~1.5-second) data. As in all ARM data filenames, the
LL indicates the data level, and the YYYYMMDD.HHMMSS have their usual
meanings. The CLASS system was replaced with a Vaisala digiCORA-III
system in late April 2002. Since that time, radiosonde data collected at
the NSA conforms with the ARM standard and, with the exception of wind
information, is identical to the radiosonde data collected at the SGP
and TWP (C1 and C2).

The NSA CLASS system (despite its name) was based on Omega windfinding.
The Omega navigation system was turned off in September 1997 and we use
pressure, temperature, humidity (PTU)- only radiosondes at NSA. After
switching to the Vaisala ground station in 2002, ARM continued the
practice of (with a few IOP and test exceptions) using PTU sondes for
production soundings at NSA. This decision was made by ARM management
based on balancing the scientific value of wind profiles against the
added operational cost of using wind-finding radiosondes.

**Soundings at Darwin, Tropical Western Pacific (TWP/C3)**

ARM obtains radiosonde data at Darwin (C3) through a collaborative
agreement with the Australian Bureau of Meteorology (BoM). Under this
agreement, BoM supplies the raw radiosonde data to ARM and ARM reformats
it and ingests it to produce ARM-standard netCDF files that are
distributed to the scientific community through the ARM Archive. Prior
to 23:15 (UTC) on January 18, 2006, when they began using Vaisala RS92
radiosondes, the BoM used Vaisala RS80 radiosondes at Darwin.
Wind-finding is done by radar tracking. Although there are four
soundings per day at Darwin, only two soundings (nominally done at 00Z
and 12Z, usually launched at 23:15 and 11:15 UTC) include all
thermodynamic data and winds. The other two soundings (04:30 and 16:30
UTC) are wind-only. Temperature and relative humidity data in the
wind-only sounding data files are coded as "missing."

**General Problems with Radiosonde Data**

Several situations may arise during a sounding that may affect the
quality of the data but which may not be flagged or otherwise corrected,
and the user should be aware of these. Among these are incorrect surface
conditions, humidity sensor saturation or icing, interference, and
signal confusion from other radiosondes. General data quality reports
(DQRs) have been issued describing these conditions, which the user is
urged to read and understand. Specific DQRs are issued for those cases
when incorrect surface conditions are included in the soundings. Cases
of sensor saturation, which may lead to unrealistic lapse rates or
humidity values aloft, and cases of sonde-to-sonde interference, which
may result in incorrect data values, are not generally called out in
individual DQRs.

**Dry Bias**

A general problem with Vaisala RS-80H (the type used by ARM from May
1992 through spring 2002) radiosondes is that they seem to exhibit a dry
bias; that is, the relative humidity values reported are too low. The
amount of the error varies with several factors including the ambient
temperature and relative humidity and the age of the radiosonde but may
be as great as 10% relative humidity. The dry bias results from
contamination of the humidity sensor during storage. Starting in August
of 1998 (week 33), Vaisala changed their packaging to reduce the
problem. Another packaging change was made in August of 2000 that
substantially reduced the bias problem from the RS-80 series of sondes.
Although more recent types of sondes (RS90, RS92) do not seem to suffer
from the same type of contamination-related bias problem, they do seem
to be biased dry during the daytime because of solar heating of the
humidity sensor during flight. This effect depends on altitude and
location and is most pronounced in the upper troposphere at lower
latitudes where solar effects are greatest. More detailed information
may be found in a frequently asked question in Section 5.4, called
"**What is this about 'dry bias' in Vaisala radiosondes?"**

**RESEARCH Mode Altitude**

Another issue involves soundings that are done in so-called RESEARCH
mode for PTU. These soundings, which may be identified by data platform
name wXpr, were done regularly at the SGP from April 27, 1994, to May
21, 1994; other isolated cases may exist in the archived data. Soundings
done using RESEARCH mode (for PTU) Vaisala processing have a negative
bias in the calculation of sonde altitude. This bias results from
neglecting the sensed relative humidity when calculating air density
when integrating the hydrostatic equation. In essence, the Vaisala
RESEARCH mode (PTU) processing assumes a dry atmosphere when calculating
sonde altitude. The magnitude of the bias is cumulative with height and
will depend on the vertical distribution of moisture, but it can be as
much as 20 m at the tropopause (the RESEARCH-mode sounding altitudes
will be smaller than altitudes calculated by using sensed relative
humidity). This problem applies to all soundings done in 'WXPR' mode,
where X is either R or N. In particular, all soundings done during the
April 1994 (RCS) IOP (April 7, 1994, to May 21, 1994) are affected as
well as those occasional inadvertent WXPR soundings. Note that the only
variable affected is 'alt.'

Users interested in corrected data for this period should obtain
filenames as listed below. They can be retrieved via the Query Interface
at the Archive or by special request to Archive User Services
(<armarchive@ornl.gov>).

-   DsgpsondeptucalcB1.c1

-   DsgpsondeptucalcB4.c1

-   DsgpsondeptucalcB5.c1

-   DsgpsondeptucalcC1.c1

**STATUS Message**

Soundings done at the SGP (BFs and CF digiCORA) and at the TWP include a
STATUS message in the netCDF metadata. This status message contains
information about the overall quality of the sounding. Among the
information included in the STATUS message is the percent of good
telemetry, and the percent of samples that did not pass the internal
quality checks. For sounding data collected with one of our digiCORA-III
ground stations, the message includes the type of radiosonde used. The
format of the STATUS message is explained in Section 5.4.

## Frequently Asked Questions

**Why are some BBSS data files from the NSA named differently than SGP
and TWP files?**

As noted in Section 5.3, the original BBSS system located at Barrow was
an old CLASS-type that was originally operated on Manus by the Climate
Monitoring and Diagnostic Laboratory. The NSA filenames (e.g.,
nsaisssonde10sC1.LL.YYYY MMDD.HHMMSS) reflect this provenance. The "iss"
refers to the integrated sounding system of which this unit was once a
part and the "10s" refers to the fact that each sample in the output
file is calculated from a 10-second window of the raw (\~1.5-second)
data. As in all ARM data filenames, the LL indicates the data level, and
the YYYYMMDD.HHMMSS have their usual meanings.

Radiosonde data files from the SGP, TWP, and recent (since 2002) files
from NSA are named SSSsondewXpXFF.LL.YYYYMMDD.HHMMSS. The "SSS" refers
to the site identifier (NSA, SGP, or TWP), the wXpX indicates the type
of processing mode that was applied to the data (X={N,R}, where N is
"nominal" and R is "research"), FF identifies the facility within the
site (for the NSA, FF={C1,C2,S0x}, for the SGP, FF={B1,B4,B5,B6,C1,S0x},
for the TWP, FF={C1,C2,C3}, and for the AMF, FF=M1).

**Why do the NSA BBSS files not have any wind data?**

The NSA CLASS system (despite its name) was based on Omega windfinding.
The Omega navigation system was turned off in September 1997 and we use
PTU only radiosondes at NSA. After switching to a Vaisala ground station
in 2002, ARM management decided to continue using PTU-only radiosondes
at NSA with exceptions for testing and those IOPs that required
wind-finding radiosondes.

**Why are some of the TWP C3 (Darwin) BBSS files missing temperature and
relative humidity data?**

The Australian BoM supplies ARM with radisonde data from their Darwin
airport station. Although the BoM does four soundings per day at Darwin,
only two soundings (nominally done at 00Z and 12Z, usually launched at
23:15 and 11:15 UTC) include all thermodynamic data and winds. The other
two soundings (04:30 and 16:30 UTC) are wind-only. Temperature and
relative humidity data in the wind-only sounding data files are coded as
"missing."

**What is RESEARCH mode?**

The standard datastream output by the BBSS ground station is passed
through different levels of processing by the ground station before
being sent to the site data system. The ground station processing
consists of filtering, editing, and interpolation. Different sets of
algorithms are applied to the wind and thermodynamic data. Data treated
by the standard processing algorithms (full filtering, editing, and
interpolation) are termed "NOMINAL" and identified in the data filename
by the letter "n" following either the "w" (for winds) or "p" (for PTU).
Thus, a sounding file with nominal processing applied to both winds and
thermodynamic data would be named SSSsondewnpnFF. In RESEARCH mode the
only processing applied to the PTU data is an 11-second window median
filter (to eliminate telemetry noise). No other processing (including
radiation correction of the temperature) is done. For winds, no editing,
filtering, or interpolation is done in RESEARCH mode. Until November 24,
2000, the standard processing mode for SGP soundings was wrpn. Since
November 24, 2000, we have been using wnpn processing modes for SGP
soundings (see BCR-00304 for further discussion).

**How do I parse the sonde serial number?**

The radiosonde serial numbers are assigned when the sensor packs are
calibrated. The numbers encode the date of calibration as well as other
information. Before October 1995, the serial number code (for RS‑80s)
was

DDMMYTTPP, in which

DD = day of the month (1-31)

MM = month (1-12) + facility identifier (00, 20, 40, or 80)

Y = last digit of the year

TT = calibration tray identifier

PP = position in calibration tray

More recent RS-80 radiosonde serial numbers are coded

YWWDTTTNN, in which

Y = last digit of the year

WW = week number (1-53)

D = day of the week (1-7) Monday=1

TTT = calibration tray identifier

NN = position in calibration tray

RS-90 radiosondes and RS-92 radiosondes (no distinction between the
types in serial number) are coded

YWWDSSSS, in which

Y = alphabetic code for the year (T=1998, U=1999, etc.)

WW = week number (1-53)

D = day of the week (1-7) Monday=1

SSSS = sequence number

**How do I decode the 'Launch Status' metadata?**

The Launch Status word is coded as follows:

SmSmSmSmSmSmSmSmSmSm NNNNNNNNNNNNNNN

IIiii

YrYrMoMoDaDa HrHrMnMn

SnSnSnSnSnSnSnSnSn

PcoPcoPco TcoTcoTco UcoUcoUco

ChnChnChn

PacPacPac PmdPmdPmd PrjPrjPrj

TacTacTac TmdTmdTmd TrjTrjTrj

UacUacUac UmdUmdUmd UrjUrjUrj

PmiPmiPmi TmiTmiTmi UmiUmiUmi

TiTiTi RRR HeHeHe

AoAoAo BoBoBo CoCoCo

DoDoDo EoEoEo FoFoFo

GoGoGo HoHoHo

aoaoao bobobo cococo

Where:

SmSmSm\... sounding number

NNN\... station name

II WMO block number

iii international station number

YrYrMoMoDaDa date of sounding

HrHrMnMn time of balloon release

SnSnSn\... radiosonde serial number

PcoPcoPco ground check correction for pressure

in tenths of a hPa

TcoTcoTco ground check correction for temperature

in tenths of a °C

UcoUcoUco ground check correction for humidity

in %RH

ChnChnChn percentage of successful attempts to

identify signal sequence

PacPacPac accepted levels of P (%)

PmdPmdPmd replaced levels of P (%)

PrjPrjPrj rejected levels of P (%)

TacTacTac

TmdTmdTmd as for P

TrjTrjTrj

UacUacUac

UmdUmdUmd as for P, T

UrjUrjUrj

PmiPmiPmi maximum interpolated layer in 10

TmiTmiTmi second units for PTU profiles

UmiUmiUmi

TiTiTi duration of ascent in 10 second units

RRR reason for termination

001 stop command

004 maximum interpolation time of

pressure or temperature exceeded

005 increasing pressure

006 prelaunch set limit exceeded

010 no PTU signal

HeHeHe altitude reach in units of 100m

**For Loran soundings (SGP)\
**

AoAoAo station in wind calculations (%)

BoBoBo Master stations are AoAoAo and

\... GoGoGo. Others are slave stations

HoHoHo

cococo

**For GPS soundings (TWP)\
**

AoAoAo percentage of valid raw wind levels

BoBoBo percentage of valid raw wind levels

which have at least 5 satellites in track

CoCoCo percentage of valid raw wind levels

which have at leave 4 satellites in track

DoDoDo percentage of raw wind levels rejected

due to poor PDOP

EoEoEo percentage of raw wind levels which

have unidentified channel in solution

FoFoFo not used

GoGoGo 10\*mean track count of all levels

HoHoHo 10\*mean track count of valid levels

aoaoao cumulative minutes of long (\>1min) time gaps

bobobo not used

cococo not used

**What is this about "dry bias" in Vaisala radiosondes?**\
\
Since the beginning of the program, ARM has conducted ongoing data
quality studies involving comparisons among different instruments. One
of the oldest of these compares the perceptible water vapor (PWV)
retrieved from the microwave radiometer (MWR) with the PWV calculated
from the radiosonde soundings. Over the years, these comparisons have
helped to detect problems with both these and other instruments. After
collecting years of data it became apparent that sequences of radiosonde
launches showed lower PWV than the MWR. At first this finding was
thought to be due to batch-to-batch calibration variations. Indeed, ARM
discovered that a large batch of Vaisala radiosondes were incorrectly
calibrated in November 1994 (see DQR960229.1).

More recent work has shown that the batch-to-batch variability in
relative humidity results from contamination of the humidity sensor by
organic vapors originating in the plastic parts of the radiosonde. The
effect of the contamination is to reduce the number of polymer binding
sites available for water vapor and thus bias the sensor output low. A
Problem Identification Report (PIF990129.5) describing the bias problem
has been filed.

Vaisala has developed a proprietary processing algorithm that is
supposed to correct the radiosonde data for the dry bias. The problem
and the algorithm is described in some detail in Lesht (1999) and Miller
et al. (1999).

# Data Quality

## Data Quality Health and Status

The following links go to current data quality health and status
results:

-   [DQ HandS](http://dq.arm.gov/) (Data Quality Health and Status)

-   [NCVweb](http://dq.arm.gov/ncvweb/ncvweb.cgi) for interactive data
    plotting using.

The tables and graphs shown contain the techniques used by ARM's data
quality analysts, instrument mentors, and site scientists to monitor and
diagnose data quality.

Click on one of the links below to look at the current/recent data
quality or operational health and status of BBSS. These various sources
will provide you with an idea of how ARM data quality analysts,
instrument mentors, site scientists, and site operators closely monitor
instrument performance in the real time.

-   **SGP**

> [Data Quality Health and Status](http://dq.arm.gov/)\
> [Sounding Status
> Reports](http://198.124.96.210:591/sonde_status/default.htm)\
> [Prelaunch Logs](http://198.124.96.210:591/bfsondelogs1/default.htm)

-   **NSA**

> [Sounding
> Logs](http://agvik.gi.alaska.edu:591/omis/nsa_maint/FMPro?-db=nsadaily.FP5&-Format=nsa_pm_results_sonde.htm&-max=20&-SortField=Date&-SortOrder=descend&-SortField=Time&-SortOrder=descend&InstrID=nsaisssondeC1&-date=&-find)

-   **TWP**

> [DSView](http://c1.dmf.arm.gov/ds/dsview/)

## Data Reviews by Instrument Mentor

The BBSS Instrument Mentors perform a number of tasks to assure the
quality of BBSS data. Data quality control procedures for this system
are considered **mature**.

-   QC frequency: Daily

-   QC delay: Real-time; weekly

-   QC type: Min/max/delta flags; graphical plots; mentor reviews

-   Inputs: Raw data files

-   Outputs: Hard copy plot of every sounding

-   Reference: None

Standard BBSS data are subject to several levels of quality control and
quality assurance. The process of converting the raw 1.5-second PTU
samples to values output every 2 seconds involves filtering, editing,
and interpolation intended to provide the best estimate of the
atmospheric state at every level. The details of the processing are not
well documented. They are being analyzed by the instrument mentor and
more information will be provided when it is available.

Daily logs that include operator comments regarding the system and a
listing of DQ flags set during the ingest are sent to instrument mentor.
He reviews these logs practically every day.

The mentor makes a hard copy plot of every sounding daily. He examines
the plots for features that may suggest a DQ problem that did not set
one of the automatic flags. The plots also are used to verify and
evaluate the DQ problems identified by the automatic procedures. If a
problem is significant enough to highlight, he writes and submits a DQR
for data users and submits a DQPR to site operators (SGP) to initiate
corrective maintenance.

The mentor receives weekly output from the ongoing Quality Measurement
Experiment (QME) involving the BBSS and the MWR
([QMEMWRCOL](http://science.arm.gov/vaps/qmemwrcol.stm)). He processes
this output to evaluate the longer-term performance of the radiosondes
by comparison with the MWR, with special attention to sonde calibration
lot. If it appears that a particular calibration lot may have a DQ
problem, he (1) issues a request to site operations personnel to hold
all remaining radiosondes from the questionable lot, (2) issues a DQR
related to all soundings done using radiosondes from the questionable
lot, and (3) contacts the manufacturer to arrange for special retesting
of the sondes from the questionable lot.

The mentor also does a weekly comparison of the surface values of
pressure, temperature, and humidity for each sounding with the
coincident measurements obtained by the collocated temperature,
humidity, winds, and pressure system (THWAPS). These comparisons help to
highlight operator data entry problems or calibration errors. Sample
comparisons (left) and sounding profiles (right) are provided in
Figure 1.

![](media/image1.png){width="2.58125in"
height="3.3409722222222222in"}![](media/image2.png){width="3.89375in"
height="3.002083333333333in"}

[]{#__RefHeading___Toc220912887 .anchor}Figure 1. Sample comparisons of
sounding profiles

## Data Assessments by Site Scientist/Data Quality Office

The **SGP Site Scientist Team and Data Quality Office** extract
automated flag information from BBSS files to produce tables of
color-coded flag status. It also performs visual inspections of
Skew-T/log p plots (from the NSDL Quicklooks Website), comparisons of
sonde and 60-m tower temperature and relative humidity (CF site only),
and comparison plots of THWAPS, Surface Meteorological Observing
Station, EBBR, and cloud mask for temperature, humidity, and pressure
(CF only). A weekly assessment report is issued to the Instrument Mentor
and SGP Site Operations in which data are verified as suitable for use,
or irregularities are noted. Such mentor and site scientist results then
trigger the writing of appropriate DQPRs (SGP) to initiate corrective
maintenance and ARM DQRs for data users.

To see these color status tables and BBSS plots, go to the [SGP Data
Quality Health and Status site](http://dq.arm.gov/). Once there, you
will see a color status table for the current month. To see the color
status for the launches of a particular day, pick a site and day, toggle
"Submit Request," and this will reveal the color status tables of the
launches made that day. If you place your mouse over non-green boxes, a
pop-up will reveal which flags were tripped and at what percentage.
Click on "Diagnostic Plot" for the launch you are interested in to see
its visuals and the NSDL quicklook for the Skew-T/log p.

The **NSA Site Scientist Team** makes visual inspections of various
sonde quicklooks and VAP-like quicklooks it has developed. For the
sondes, profiles of air temperature, dewpoint temperature, relative
humidity, and water vapor are produced at 10-second averages over 0-1 km
and 0-10 km profiles, respectively. Total column water vapor is also
derived and compared to that from the MWR to detect possible
discrepancies. On-line versions of such plots can be seen from the NSA
quicklook server links in "**Data Quicklooks (near real-time)"** below.

Two sample sonde diagnostic plots that can be found on the NSA quicklook
server are shown in Figure 2, one for the 0-1 km profile (left) and
another for 0-10 km profile (right).

![](media/image3.png){width="3.240972222222222in"
height="2.220138888888889in"}![](media/image4.png){width="3.240972222222222in"
height="2.267361111111111in"}

[]{#__RefHeading___Toc220912888 .anchor}Figure 2. Sample sonde
diagnostic plots

The **TWP Site Scientist Team** tests for missing sondes. Total column
water vapor is derived and compared to that from the MWR to detect
possible discrepancies. Diagnostic plots and further sonde checks are
currently under construction.

## Value-Added Procedures and Quality Measurement Experiments

Many of the scientific needs of the ARM Program are met through the
analysis and processing of existing data products into "value-added"
products. Despite extensive instrumentation deployed at the ACRF sites,
there will always be quantities of interest that are either impractical
or impossible to measure directly or routinely. Physical models using
ARM instrument data as inputs are implemented as "value-added" products
and can help fill some of the unmet measurement needs of the program.
Conversely, ARM produces some "value-added" products not to fill unmet
measurement needs, but instead to improve the quality of existing
measurements. In addition, when more than one measurement is available,
ARM also produces "best estimate" "value-added" products. A special
class of "value-added" product called a QME does not output geophysical
parameters of scientific interest. Rather, a QME adds value to the input
datastreams by providing for continuous assessment of the quality of the
input data based on internal consistency checks, comparisons between
independent similar measurements, or comparisons between measurement
with modeled results, and so forth. For more information, see the [VAPs
and QMEs](http://www.arm.gov/data/vaps_all.php) Web page.

BBSS-related "value-added" products include:

-   [[LSSONDE]{.underline}](http://science.arm.gov/vaps/lssonde.stm) --
    Produces radiosonde profiles in which the moisture profile is scaled
    to match MWR total perceptible water vapor.

BBSS-related QMEs include:

-   [[QMEMWRCOL]{.underline}](http://science.arm.gov/vaps/qmemwrcol.stm)
    -- Results from this QME are used to evaluate the MWR and
    radiosondes.

-   [[QMEMWRPROF]{.underline}](http://science.arm.gov/vaps/qmemwrp.stm)
    -- Comparisons of retrieved water vapor and temperature profiles
    from mwrprof with radiosonde profiles.

-   [[QMEAERIPROF]{.underline}](http://science.arm.gov/vaps/qmeapro.stm)
    -- This QME helps to assess the ability of the radiosondes and in
    situ tower measurements to observe moisture and temperature in the
    atmosphere.

-   [[QMEAERILBLCLOUDS]{.underline}](http://science.arm.gov/vaps/qmealbc.stm)
    -- Uses radiosonde pressure, temperature, and moisture data as
    input.

# Instrument Details

## Detailed Description

### List of Components

The BBSSs consist of disposable radiosondes and fixed ground stations.
All facilities use the same basic radiosondes, but the ground stations
differ somewhat. Each ACRF site uses Vaisala ground stations.

**Radiosondes:**

ARM practice has been to adopt the most advanced radiosonde technology
provided by Vaisala as soon as it has been proven. ARM was the first
large-scale program to use the advanced H-Humicap in the RS80 family of
radiosondes, the first research program to make the transition to the
dual-humicap RS90 family, and the first program to use the RS92 family.
Before making the change between radiosonde types, ARM conducted
month-long transition IOPs during which the new type of radiosonde was
flown alongside the type being replaced. Each of these experiments took
place at the SGP.

-   Manufacturer: [Vaisala, Inc.](http://www.vaisala.com/)

-   AMF

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-   RS92-SGP (GPS windfinding)

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-   SGP

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-   RS80-15LH (Loran-C windfinding, H-Humicap, 403 MHz) through April
    2001

-   RS90-AL (Loran-C windfinding, dual humicap) beginning May 2001

-   RS92-KL (Loran-C windfinding, dual humicap) beginning 17:30 UTC
    February 9, 2005

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-   TWP

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-   RS80-15GH (GPS windfinding, H-Humicap, 403 MHz) through May 2002

-   RS90-AG (GPS windfinding, dual humicap) beginning June 2002

-   RS92-SGP (SGP windfinding, dual humicap) beginning April 2005

-   RS80-15 (Radar-tracked winds) at Darwin (C3) to January 18, 2006
    (1630 UTC)

-   RS92-15 (Radar-tracked winds) at Darwin (C3) beginnin January 18,
    2006 (2315 UTC)

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-   NSA

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-   RS80-15H (PTU only, H-Humicap, 403 MHz) used with CLASS through
    April 2002

-   RS90-A (PTU only, dual humicap) beginning April 25, 2002

-   RS90-AG Occasionally in use beginning April 25, 2002

-   RS92-K (PTU only) and RS92-SGP (GPS windfinding) in use occasionally
    beginning January 2005.

**Ground Stations:**

The essential attributes of the ground stations employed by ARM are
reported in Tables 1 and 2.

### System Configuration and Measurement Methods

Original sampling rate (May 27, 1992, to May 30, 1993):

The raw sampling rate of thermodynamic sensors is approximately 1.5
seconds. The rate at which processed data is output to the datastream is
programmable. For the first several months of operation at the SGP site,
we used a scheme in which PTU and wind data were output at three
different rates, depending on the time into the sounding. These sampling
rates were as follows:

-   Sample output every 10 seconds from 0 to 120 seconds into the
    flight.

-   Sample output every 30 seconds from 120 to 900 seconds into the
    flight.

-   Sample output every 60 seconds from 900 seconds to the end of the
    flight.

Sampling rate (NSA) to May 1, 2002:

-   Thermodynamic variables (PTU) output every ten seconds throughout
    the flight.

-   Wind variables (speed, direction) were not measured.

Sampling rate (SGP/TWP) from June 1, 1993, to November 24, 2000:

-   Thermodynamic variables (PTU) output every two seconds throughout
    the flight.

-   Wind variables (speed, direction):

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-   Output every ten seconds (SGP)

-   Output every two seconds (TWP).

Current Sampling rate (SGP/TWP/NSA):

-   Thermodynamic variables (PTU) output every two seconds throughout
    the flight.

-   Wind variables (speed, direction) output every two seconds
    throughout the flight.

Balloons and rate of ascent:

ARM uses 350-gal balloons at all sites. The nominal ascent rate is
approximately 5 m/s, although this is variable during the flight. The
data file includes a variable 'asc' which, for each sample, estimates
the current rate of ascent. This rate is actually a 30-second average
rise rate based on the calculated sonde altitudes.

**Software Configuration of the SGP digiCORA Systems**

The following links are to the current software configuration listings
for the Vaisala MW-11 and MW-15 digiCORA systems now in use at the NSA,
SGP, and TWP sites. As shown in Table 1, the MW-11 systems are nominally
assigned to BF1 (Hillsboro, Kansas), BF4 (Vici, Oklahoma), BF5

(Morris, Oklahoma), and BF6 (Purcell, Oklahoma). Three MW-15 systems are
assigned to TWP (C1, C2, spare) and one to SGP (spare). The
configuration listings show the installed software applications as well
as their version numbers.

**SGP**

BF1

[BF4](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/MW11s574792S01.20050801.conf.txt)

BF5

[BF6](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/MW11s708515S02.20050801.conf.txt)

Spare

**TWP**

C1

C2

Spare

### Specifications

The manufacturer's specifications for the thermodynamic sensors are as
follows:

PRESSURE

Type: Capacitive aneroid

Range: 1060 hPa to 3 hPa

Resolution: 0.1 hPa

Accuracy: 0.5 hPa

TEMPERATURE

Type: Capacitive bead

Range: +60°C to -90°C

Resolution: 0.1°C

Accuracy: 0.2°C

Lag: \<2.5 s (6 m/s flow at 1000 hPa)

HUMIDITY

Type: H-HUMICAP thin film capacitor

Range: 0 to 100 %RH

Resolution: 1 %RH

Accuracy: 2 %RH (0 to 80 %RH)

3 %RH (80 to 100 %RH)

Lag: 1 s (6 m/s flow at 1000 hPa, +20°C)

Note that the "accuracy" figures given by the manufacturer represent the
standard deviation of the differences obtained from repeated
calibrations. As such, these values are more properly termed
"precision." Operational experience at the SGP site [(Lesht
1995)](#Ref1) showed that the root mean square error in RH was
approximately 1% RH at low humidity and surface temperature and that the
root mean square error in temperature was approximately 0.3°C.

**Winds**

Wind information (SGP) is obtained by tracking the radiosonde's position
using the Loran-C navigation system. The accuracy of the wind
information depends on the configuration of the Loran-C stations that
are used to locate the sonde. Loran-C coverage in the SGP area is fairly
good, and we estimate the accuracy of the wind speed to be approximately
0.5 m/s.

We use GPS wind-finding at the TWP locations. This satellite-based
navigation system is very precise and we estimate the accuracy of the
wind velocity to be 0.2 m/s.

## Theory of Operation

This section is under construction.

## Calibration

### Calibration Theory

This section is under construction.

### Calibration Procedures

This section is under construction.

### Calibration History

This section is not applicable to this instrument.

## Operation and Maintenance

### User Manual

Each site maintains its own radiosonde launch procedures. The Vaisala
User's Manual for the digiCORA-III system may be accessed
[here](http://www.arm.gov/publications/tech_reports/handbooks/bbssinstrumentdocs/M210488EN-B.pdf).

### Routine and Corrective Maintenance Documentation

The following link points to the [General Preventative Maintenance
Procedures](http://198.124.96.210/common/main_menu.htm) in place for all
sites

### Software Documentation

This section is under construction.

### Additional Documentation

This section is not applicable to this instrument.

## Glossary

See the [ARM Glossary](http://www.arm.gov/about/glossary.stm).

## Acronyms

See the [ARM Acronyms and
Abbreviations](http://www.arm.gov/about/acronyms.stm).

# Citable References

[]{#Ref1 .anchor}Lesht, BM. 1995. "An evaluation of ARM radiosonde
operational performance." *Proceedings of the Ninth Symposium on
Meteorological Observations and Instrumentation,* pp. 6-10. American
Meteorological Society, Boston, Massachusetts.

Lesht, BM. 1999. "Reanalysis of radiosonde data from the 1996 and 1997
water vapor intensive operations periods: Application of the Vaisala
RS-80H contamination correction algorithm to dual-sonde soundings." In
*Proceedings of the Ninth Atmospheric Radiation Measurement (ARM)
Science Team Meeting.* U.S. Department of Energy, ARM-CONF-1999,
http://www.arm.gov/publications/proceedings/conf09/author.stm.

Miller, ER, J Wang, and HR Cole. 1999. "Correction for dry bias in
Vaisala radiosonde RH data." In *Proceedings of the Ninth Atmospheric
Radiation Measurement (ARM) Science Team Meeting*. U.S. Department of
Energy, ARM-CONF-1999,
http://www.arm.gov/publications/proceedings/conf09/author.stm.

## Bibliography

Lesht, BM, and JC Liljegren. 1996. "Comparison of precipitable water
vapor measurements obtained by microwave radiometry and radiosondes at
the Southern Great Plains CART site." In *Proceedings of the Sixth
Atmospheric Radiation Measurement (ARM) Science Team Meeting*. U.S.
Department of Energy, DOE-CONF-9603149,
http://www.arm.gov/publications/proceedings/conf06/index.stm.

Mattioli, V, ER Westwater, D Cimini, JS Liljegren, BM Lesht, S Gutman,
and F Schmidlin. 2005. "Analysis of radiosonde and precipitable water
vapor data from the 2004 North Slope of Alaska Arctic Winter Radiometric
Experiment." In *Proceedings of the Fifteenth Atmospheric Radiation
Measurement (ARM) Science Team Meeting*, U.S. Department of Energy,
DOE/SC-ARM-0503.

Miloshevich, LM, BM Lesht, and M Ritsche. 2004. "New surface
meteorological measurements at SGP, and their use for assessing
radiosonde measurement accuracy." In *Proceedings of the Fourteenth
Atmospheric Radiation Measurement (ARM) Science Team Meeting*. U.S.
Department of Energy, ARM-CONF-2005,
http://www.arm.gov/publications/proceedings/conf15/index.stm.

Miloshevich, LM, BM Lesht, and H Voemel. 2004. "Evaluation of ARM
radiosonde humidity measurements and proposed corrections based on AWEX
radiosonde intercomparisons." Presented at Fourteenth Atmospheric
Radiation Measurement (ARM) Science Team Meeting. Albuquerque,
New Mexico. March 22-26, 2004.

Soden, BJ, DD Turner, BM Lesht, and LM Milosevich. 2004. "An analysis of
satellite, radiosonde, and lidar observations of upper tropospheric
water vapor from the Atmospheric Radiation Measurement program."
*Journal of Geophysical Research* 109:D04105.

Westwater, ER, BB Stankov, D Cimini, Y Han, JA Shaw, BM Lesht, and CN
Long. 2003. "Radiosonde humidity soundings and microwave radiometers
during Nauru99." *Journal of Atmospheric and Oceanic Technology*
20:953--971.

[^1]: See discussion of NSA radiosonde systems in Section 5.3 (User
    Notes)

[^2]: See discussion of Darwin radiosonde systems in Section 5.3 (User
    Notes)

[^3]: D indicates system was deployed at the NSA Duplex location; GW
    indicates system was deployed at the NSA Great White location.

[^4]: Raw thermodynamic ASCII files are produced regularly only by the
    digiCORA-III systems at AMF, NSA, and SGP. Similar files can be
    provided for other systems/locations on request to the instrument
    mentors.