U. Michigan Radiobrightness Energy Balance Experiment-5 (REBEX-5)

University of Michigan Tower Mounted Radiometer System photo by Brian Hornbuckle

Overview The Data Characteristics Source The Files Format The Science Data Access and Contacts FTP Site Points of Contact

TMRS Data Participants TMRS Home, UMich Ground remote sensing page

Overview

During SGP97, the University of Michigan conducted its fifth Radiobrightness Energy Balance Experiment (REBEX-5). Sky and ground radiobrightness were observed at 19.35, 37.0 and 85.5 GHz, and at thermal infrared frequencies using the Tower Mounted Radiometer System (TMRS). These observations were realted to contemporaneous SSM/I data. The dominant landcover was senescent winter wheat and after the wheat was harvested, wheat stubble. The relatively low canopy column density in either case allowed some sensitivity to surface soil moisture at 19 GHz.

The Data

Characteristics

Files	tmrs.wheat	tmrs.sky43	tmrs.sky56
Parameters	Ground Brightness	Downwelling sky brightness	Downwelling sky brightness
Units	Kelvin	Kelvin	Kelvin
Temporal Coverage	Day 170 - day 199 for all files
Temporal Resolution	30 min	30 min	30 min
Spatial Coverage	cf02	NA	NA
Spatial Resolution	4mX2m	NA	NA
Notes:	**All Day fields in the above files are in Julian Day starting from Jan. 1, 1997, Central Daylight Savings Time (CDT). **The data at 85 GHz have some calibration problems and have an accuracy of +/- 3 Kelvin **The zenith angle for the sky measurements have an accuracy of +/- 2 degrees **Wheat was harvested on JD 176.6667 (4pm CDT on June 25, 1997)

Source

The Tower Mounted Radiometer System (TMRS) consists of 19 and 37 GHz dual­polarized and 85 GHz horizontally­polarized microwave radiometers, an infra­red radiometer, a video camera installed on a 10 meter tower. The radiometers and the video camera were situated in a housing tilted at the SSM/I satellite incidence angle of 53^o . Microwave sky and ground brightness were measured every 30 minutes. Data acquisition and storage were controlled by a computer housed inside an enclosed 8' X 10' trailer.

The Files

Format

There are three ASCII data files and a "readme" file from the University of Michigan's Tower Mounted Radiometer System (TMRS) data set.

File	Format	Size in bytes
tmrs.wheat	ascii	66449
tmrs.sky43	ascii	49236
tmrs.sky56	ascii	49236
tmrs.readme	ascii	1190

The Science

The tower was situated at the Central Facility area (CF02) and monitored winter wheat/stubble at the SSM/I incidence angle of 53^o. Diurnal vegetation and soil samples were collected periodically throughout the experiment. SSM/I data has been obtained from NSIDC and will be resampled to the Equal Area SSM/I Earth - grid (EASE - grid) for comparison with the REDEX-5 data.

The Land Surface Process/Radiobrightness (LSP/R) model was used to relate brightness at L-, C-, and S-band frequencies, and at the SSM/I frequencies to surface soil moisture and to local stored water. The LSP/R model has been validated in a series of Radiobrightness Energy Balance Experiments (REBEX) for prairie grassland in fall and winter (REBEX-1) and prairie grassland and bare soil in summer (REBEX-4). Our REBEX-5 data was combined with available SGP97 meteorological and radiant flux data to validate the LSP/R model for winter wheat/stubble to predict 19, 37, and 85 GHz brightness for each of the dominant terrains within the SGP'97 region. These brightness were aggregated for each local pixel of EASE-grid according to landcover fractions to yield a pixel brightness that can be compared with the resampled SSM/I data. Of particular interest is a running comparison during a significant dry down period.

Data Access and Contacts

FTP Site

The University of Michigan Microwave Radiometer data is available in the following GES DISC ftp site:

TMRS data online

Points of Contact

For science or instrument information contact:

 

Jasmeet Judge

Radiation Lab

3124 EECS Building

1301 Beal Ave

Ann Arbor, MI 48109-2122

jasmeet@eecs.umich.edu

734-763-4185 (Voice)

734-647-2106 (Fax)

OR

Tony England

Radiation Lab

3124 EECS Building

1301 Beal Ave

Ann Arbor, MI 48109-2122

england@umich.edu

734-763-5534 (Voice)

734-647-2106 (Fax)

For information regarding GES DISC data contact:

Hydrology Data Support Team

Goddard Earth Sciences
Data and Information Services Center (GES DISC)

Code 610.2

NASA Goddard Space Flight Center

Greenbelt, Maryland 20771

E-mail : hydrology-disc@listserv.gsfc.nasa.gov

301-614-5165 (voice)

301-614-5268 (fax)

Last update:Mon Feb 1 13:16:05 EST 1999 Page Author: Hydrology Data Support Team -- hydrology-disc@listserv.gsfc.nasa.gov Website Curator: Stephen W Berrick NASA official: Steve Kempler, DAAC Manager --Steven.J.Kempler@nasa.gov