PSR/A Multiband Polarimetric Imaging, Wakasa Bay, Japan

Summary

This data set includes brightness temperature data measured over the Sea of Japan, the Western Pacific Ocean, and the Japanese Islands in January and February 2003. The data were collected using the NOAA Environmental Technology Laboratory (ETL) Polarimetric Scanning Radiometer (PSR/A), an airborne multiband, conical-scanning, imaging radiometer system. The PSR was mounted to a NASA P-3 aircraft and flown at approximately 22,000 ft mean sea level (MSL) with flight lines that crossed maritime and orographic precipitation. These data are provided to AMSR-E Validation scientists for use in intercomparisons with surface-based and satellite-based data collected during the January/February 2003 Wakasa Bay Field Campaign. Data are available in MATLAB format and as binary files with accompanying ASCII headers.

The Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) is a mission instrument launched aboard NASA's Aqua satellite on 4 May 2002. The Wakasa Bay Field Campaign was designed to validate both AMSR and AMSR-E shallow rainfall and snowfall retrieval capabilities.

Citing These Data

Stankov, B. and A. J. Gasiewski. 2005. PSR/A Multiband Polarimetric Imaging, Wakasa Bay, Japan. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Overview Table

Category Description
Data format Data are provided in MATLAB and binary format. Browse images of selected brightness temperature (TB) maps are provided in JPEG format.
Spatial coverage and resolution Spatial coverage is 30°N to 42°N, 132°E to 151°E. Spatial resolution varies from 0.3 km to 2.2 km, depending on the channel and type of scan.
Temporal coverage 19 January 2003 to 03 February 2003
Tools for accessing data MATLAB programs to display TB maps are available via FTP.
File size File sizes range from 300 bytes (text files) to 60 MB (MATLAB and binary files).
Parameter(s) Calibrated brightness temperatures (TBs) in Kelvins
Procedures for obtaining data Data are available via FTP.

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts and Acknowledgments

Investigator(s) Name and Title

Boba Stankov
NOAA/Environmental Technology Laboratory
Division of Microwave Systems Development
325 Broadway
Boulder, CO 80305-3328

Albin J. Gasiewski
NOAA Environmental Laboratory
Division of Microwave Systems Development
325 Broadway R/ET1
Boulder, CO 80305-3328

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Detailed Data Description

This data set represents one in a series of aircraft campaigns to validate rainfall algorithms developed for the Advanced Microwave Scanning Radiometer (AMSR) sensor aboard the ADEOS-II satellite and the AMSR-Earth Observing System (AMSR-E) sensor aboard NASA's Aqua satellite. The AMSR/AMSR-E Wakasa Bay Field Campaign was conducted over Wakasa Bay, Japan, and was designed to:

1. Validate both AMSR and AMSR-E shallow rainfall and snowfall retrievals.

2. Extend the database of rainfall properties needed to implement a comprehensive physical validation scheme.

3. Extend understanding of rainfall structures through new remote sensing technology.

The Wakasa Bay Field Campaign was extended into 2003 with joint research observations by the Japan Aerospace Exploration Agency (JAXA, Contractor: Mitsubishi Electric Corporation), AMSR precipitation validation team, and the NASA AMSR-E team.

This data set includes brightness temperatures collected from the NOAA Environmental Technology Laboratory's (ETL's) Polarimetric Scanning Radiometer (PSR/A), an airborne multiband, conical-scanning, imaging radiometer system mounted to a NASA P-3 aircraft.

Summary of Wakasa Bay 2003 Flights
Region Observed
Date
Observation Times (UTC)
# of Flight Lines
% Time PSR Operated
Flight Altitude (km MSL)
Sea of Japan
2003-01-14
02:51 - 09:18
1,1
0
7, 0.15
Honshu
2003-01-15
03:03 - 06:49
4
80
7
Western Pacific
2003-01-19
02:58 - 09:52
2, 1, 1, 1, 1, 1
95
7, 5, 4, 3, 2, 0.15
Western Pacific
2003-01-21
02:05 - 08:26
2, 1, 1
95
7, 3, 0.15
Western Pacific
2003-01-23
06:23 - 10:54
2, 2
100
7, 3
Honshu
2003-01-26
03:27 - 04:48
4
100
7
Sea of Japan
2003-01-27
02:08 - 07:34
5, 1
100
7, 5
Sea of Japan
2003-01-28
02:25 - 08:07
5, 1
100
7, 5
Sea of Japan
2003-01-29
02:14 - 06:37
5, 1
100
7, 5
Sea of Japan
2003-01-30
02:06 - 07:19
5, 1
100
7, 5
Honshu
2003-02-01
03:14 - 04:31
2
100
7
Western Pacific
2003-02-03
02:00 - 06:24
3, 1
100
7, 0.15
TOTAL
62:17
60

Brightness temperature data were processed to Level2.3a (L23a) and are provided to AMSR-E Validation scientists for use in intercomparisons with surface-based and satellite-based data collected during the January/February 2003 field campaign. The letter "a" stands for a subset of PSR data provided to outside users.

The PSR/A scanhead operated in both conical and cross-track scan mode. The conical mode used an incidence angle of 55 degrees from nadir. PSR imaging occurred at medium altitude (approximately 22,000 ft MSL) during flight lines that crossed maritime and orographic precipitation. Both snow and moderate to light rain were observed. Several low-altitude (approximately 700 ft MSL) lines were also flown for surface emission studies. See the Temporal Coverage section of this document for more detailed information about each flight.

Format

Data are provided in two formats: MATLAB and binary with an ASCII header file.

MATLAB version 6.1 or greater is required to view the MATLAB files, which are organized as shown in the tables below. Users must configure the file "setrootdir.m" (in the "display_23a" directory) to include the proper local directory where PSR data files are stored.

Binary files ("L23axxxx.bin") contain data written out as a long line of sequential points of binary data in the order described in the following tables. Indices in a three-dimensional PSR/A data matrix indicate (1) scan, (2) sample within a scan, and (3) data type as explained in the tables below. Each binary file has an associated ASCII header file ("L23axxxx.txt"). An example of an ASCII header is as follows:

PSR/A
Julian day at the beginning of the flight: 28
PSR scanhead type: PSRA
Maneuver serial number: 1308
Size of sceneL23a data matrix is (numscans,numsamples,numchannels): sceneL23a(486,125,28)
Binary data file: C:\PSR\WBAY03\2003_0128\level2.3a\SL\L23a1308.bin is written as real*8 (double) i.e., floating point; 64 bits

 

PSR/A Data Type (order of variables in the third dimension)
Data Plane Description
sceneL23a(:,:,1) 10.7v GHz vert. polarization brightness temperature (TB)

sceneL23a(:,:,2)

10.7h GHz horiz. polarization brightness temperature (TB)
sceneL23a(:,:,3) 18.7v GHz vert. polarization brightness temperature (TB)
sceneL23a(:,:,4) 18.7h GHz horiz. polarization brightness temperature (TB)
sceneL23a(:,:,5) 21.5v GHz vert. polarization brightness temperature (TB)
sceneL23a(:,:,6) 21.5h GHz horiz. polarization brightness temperature (TB)
sceneL23a(:,:,7) 37.0v GHz vert. polarization brightness temperature (TB)
sceneL23a(:,:,8) 37.0h GHz horiz. polarization brightness temperature (TB)
sceneL23a(:,:,9) 89.0v GHz vert. polarization brightness temperature (TB)
sceneL23a(:,:,10) 89.0h GHz horiz. polarization brightness temperature (TB)
sceneL23a(:,:,11) 10.0 um Infrared brightness temperature (TB)
sceneL23a(:,:,12) Scanhead encoder position azimuth
sceneL23a(:,:,13) Scanhead encoder position elevation
sceneL23a(:,:,14) High data rate attitude data pitch
sceneL23a(:,:,15) High data rate attitude data roll
sceneL23a(:,:,16) Latitude
sceneL23a(:,:,17) Longitude
sceneL23a(:,:,18) Heading
sceneL23a(:,:,19) Altitude (ft)
sceneL23a(:,:,20) Ambient Temperature
sceneL23a(:,:,21) Ground Speed
sceneL23a(:,:,22) Hardware trigger value
sceneL23a(:,:,23) Time stamp (sec from the beginning of the day)
sceneL23a(:,:,24) True azimuth angle
sceneL23a(:,:,25) True elevation angle
sceneL23a(:,:,26) Polarization angle
sceneL23a(:,:,27) Pixel terrain geolocated latitude (dd.ddd)
sceneL23a(:,:,28) Pixel terrain geolocated latitude (dd.ddd)

 

Additional Variables Present in each PSR/A WBAY03 Level 2.3a File
ssn Serial number of maneuver (see CLPX02 data flight catalog)
firstday Julian day on which the flight began
scanhead Type of PSR scanhead (e.g., PSRA for CLPX02)
description Text string indicating PSR maneuver ID

 

File and Directory Structure

Data are available via FTP with the following directory structure:

Directory Description
2003_0119
2003_0121
2003_0123
2003_0126
2003_0127
2003_0128
2003_0129
2003_0130
2003_0201
2003_0203
Flight code directories indicate the year, month, and day of the beginning of the flight. Each of these contains "level2.3a" directories, followed by "CAT" (constant-angle turns) and "SL" (straight-and-level) directories with MATLAB data files (*.mat), binary data files (*.bin), and ASCII headers (*.txt). The "SL" directories also contain browse images of TB maps in JPEG format.
display_23a Contains MATLAB Version 6.1 executable files (*.m) necessary to render TB maps from PSR/A data. Users must configure the file "setrootdir.m" (located in the display_23a directory) to include the proper local directory where PSR data files are stored.

File Naming Convention

"L23axxxx.mat" are data files in MATLAB format, corresponding to a maneuver with serial number xxxx. "L23axxxx.bin" are data files in binary format, corresponding to a maneuver with serial number xxxx. Binary data are identical to the MATLAB data, except the binary files have accompanying header files ("L23axxxx.txt"). Serial numbers for each maneuver are listed on page 12 in a data delivery report that accompanies this data set, PSR/A Multiband Polarimetric Imaging During Wakasa Bay (WBAY03) Field Campaign (PDF file, 2.8 MB).

File Size

File sizes range from 300 bytes (text files) to 60 MB (MATLAB and binary files).

Spatial Coverage

The Wakasa Bay coordinates are:

Southernmost Latitude: 30° N
Northernmost Latitude: 42° N
Westernmost Longitude: 132° E
Easternmost Longitude: 151° E

Spatial Resolution

Spatial resolution varies from 0.3 km to 2.2 km, depending on the channel and type of scan, as the following table shows:

PSR/A Scanhead Characteristics
Band (GHz)
Polarizations
Beamwidth
Surface Resolution (km) at 22,000' MSL observing altitude
Conical Scan
Cross-Track Scan (nadir)
10.6 - 10.8
v,h
2.2
0.9
18.6 - 18.8
v,h
2.2
0.9
21.4 - 21.7 (H2Ov)
v,h
2.2
0.9
36 - 38
v,h
2.3°
0.6
0.3
86 - 92
v,h
2.3°
0.6
0.3
9.6 - 11.5 µm IR
v+h
1.9
0.8

Temporal Coverage

Data are available from 19 January 2003 to 03 February 2003. Flights occurred on 14 and 15 January, but no data are distributed for these dates at this time. Following are summaries of all flights, quoted from PSR/A Multiband Polarimetric Imaging During Wakasa Bay (WBAY03) Field Campaign.

14 January 2003: ~6.0-hour snow showers mapping mission over Sea of Japan (Fig. 1). PSR/A scanhead was not operating due to a problem with the 89 GHz receiver.

15 January 2003: ~4-hour snow showers mapping mission over the mountains of Honshu, just north of Tokyo and along the Sea of Japan coast. PSR/A scanhead operated well but the tempscan data were not recorded. Data processing for this flight will require more attention and thus we are not providing them in this data delivery.

19 January 2003: ~7.0-hour rainstorm mapping mission. Rainstorm started south of Honshu and moved northeastward to Western Pacific while deepening explosively. Seven observation lines at various altitudes and with PSR/A scanning in cross-track or conical mode were completed.

21 January 2003: ~6.0-hour mission to observe frontal rain bands associated with eastmoving low pressure area that formed over the Kanto plain during night with rain and snow reported in local area. Even reports of thunder-snow were recorded. The low moved rapidly over the Western Pacific Ocean generating copious rain.

23 January 2003: ~4.0-hour mission to observe eastward moving cold front and frontal rain/snow bands. A low had passed out of the Yellow sea, across Kyushu and along the southern edge of Honshu with a cold front trailing out of the low. The low tracked to the NE and deepened explosively.

26 January 2003: ~1.5-hour mission to observe land background in clear air and with conical scanning mode during the AMSR-E overpass.

27 January 2003: ~5.0-hour Wakasa Bay rain data flight to observe light rain and snow over Sea of Japan during the AMSR-E overpass.

28 January 2003: ~5.5-hour over roughly the same area as on 27 January 2003 to observe snow over water that was a result of strong onshore flow with scattered snow showers all along the central Sea of Japan coast of Honshu.

29 January 2003: ~4.5-hour over roughly the same area as on 27 and 28 January 2003 to observe snow over water. Strong northwesterly flow over all of the Sea of Japan produced extensive areas of heavier snow off the coast of Honshu.

30 January 2003: ~5.0-hour over roughly the same area as on 27, 28, and 29 January 2003 to observe snow over water. However, snow was observed in the Wakasa Bay but did not extend too far over the Sea of Japan.

01 February 2003: ~1.0-hour Wakasa Bay data flight to observe snow covered land background in clear air and using conical scanning mode.

03 February 2003: ~4.0-hour flight over the SE Pacific Ocean to observe rain over the water that was associated with a low southwest of Kanto region.

Parameter or Variable

Parameter Description

This data set contains calibrated brightness temperatures (TBs) in Kelvins.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

Total data volume is approximately 3.43 MB.

Software and Tools

MATLAB version 5.3 or greater is required to view MATLAB data. The MATLAB programs to display TB maps are available via FTP. Users must configure the file "setrootdir.m" (located in the display_23a directory) to include the proper local directory where PSR data files are stored.

Also included is a MATLAB file, "ReadBinL23aFile.m", which is an example of how to read binary and text files. The information in this file is intended to help users in designing their own data-reading routine using the software of their choice.

Related Data Collections

4. Data Acquisition and Processing

Sensor or Instrument Description

A U.S. Navy P-3 Orion aircraft carried the PSR/A sensor. The PSR/A has fully polarimetric channels at 10.7 GHz and 18.7 GHz; tri-polarimetric channels at 37 GHz and 89 GHz; and a dual-polarimetric channel at 21.5 GHz. See the Spatial Resolution section of this document for a table of PSR/A scanhead characteristics. Also see the NOAA Environmental Laboratory's Polarimetric Scanning Radiometer instrument description.

5. References and Related Publications

Stankov, B., A.J. Gasiewski, M. Klein, V. Leuski, V. Irisov, and B. Weber. 2003. PSR/A multiband polarimetric imaging during Wakasa Bay (WBAY03) field campaign: data delivery report to NASA PIs. Boulder, CO: NOAA Environmental Laboratory, Division of Microwave Systems Development. Unpublished report.

6. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

AMSR Advanced Microwave Scanning Radiometer (ADEOS-II satellite)
AMSR-E Advanced Microwave Scanning Radiometer - Earth Observing System (Aqua satellite)
ASCII American Standard Code for Information Interchange
CLPX Cold Land Processes Experiment
ETL Environmental Technology Laboratory
FTP File Transfer Protocol
MSL Mean Sea Level
PSR/A Polarimetric Scanning Radiometer (analog)

Document Creation Date

June 2005

Document Revision Date

August 2005

Document Review Date

June 2005

Document URL

http://nsidc.org/data/docs/daac/nsidc0267_rainfall_wakasa_psr.gd.html