The MIR data set is part of the atmospheric measurements collected in the intensive observation period of the Tropical Ocean Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE). Dr. James Wang/GSFC and Paul Racette/GSFC are co-investigators on this instrument. The MIR data are archived at the Goddard Distributed Active Archive Center (DAAC).
2.1 Instrument Science ObjectivesMIR was flown on the NASA ER-2 from January 12 through February 24, 1993. The overall measurement objectives of the MIR include the evaluation of millimeter wavelengths for the detection and estimation of convective rainfall, and the study of the effects of cloud microphysical structures on rainfall estimation and water vapor profiles. The collected data will be useful in developing algorithms for interpreting data collected from future spaceborne microwave sensors such as Advanced Microwave Sensor Unit (AMSU) that will be flown onboard the EOS PM satellite.2.2 Instrument Geometry
The MIR was nadir-oriented in the forward compartment of the right wing pod of the ER-2 aircraft. It scannned in a plane perpendicular to the direction of flight with a swath of +/- 50 degrees from nadir. Each scan took 3 seconds and produced 57 brightness temperature values.
2.3 Principals of Operation
The following table summarizes some characteristics of the MIR radiometer
Channel Bandwidth Temperature Res. Beamwidth 89 GHz 1.0 GHz <0.2 K 3.5 Deg. 150 1.0 <0.2 3.5 220 3.0 <0.3 3.5 184 1.0 <0.4 3.5 186 2.0 <0.3 3.5 190 2.0 <0.5 3.5
3.1 General Characteristics3.2 Data formatThe MIR data consist of calibrated brightness temperatures in degrees Kelvin at 89, 150, 183.3+/-1, 183.3+/-3, 183.3+/-7 and 220 GHz.
The total volume of the MIR data set is ~148 MB. There are 12 MIR data files, each containing data from one mission flight of the NASA ER-2. These files have a typical size of ~12.5 MB. The file naming convention is
toga_flightXX.mirwhere XX is a 2-digit flight number.3.1.1 Flight coordination table. The following table relates MIR filenames to ER-2 and DC-8 flight numbers and dates for the 13 mission flights of the NASA/TOGA COARE campaign. Also included is ER-2 flight 93-061 of February 7, that produced MIR data although it is not designated as a mission flight.
Date(UTC) ER-2 Flight DC-8 Flight MIR Filename Jan 11-12 93-053 93-01-06 toga_flight01.mir Jan 17-18 93-054 93-01-07 toga_flight02.mir Jan 18-19 93-055 93-01-08 toga_flight03.mir Jan 25-26 93-056 93-01-09 toga_flight04.mir jan 31-Feb 1 93-058 93-01-10 toga_flight05.mir Feb 4 93-060 93-01-11 toga_flight06.mir Feb 6 93-01-12 Feb 7 93-061 toga_flight07.mir Feb 8-9 93-062 93-01-13 toga_flight08.mir Feb 10-11 93-063 93-01-14 toga_flight09.mir Feb 17-18 93-01-15 Feb 20-21 93-065 93-01-16 toga_flight10.mir Feb 22-23 93-066 93-01-17 toga_flight11.mir Feb 23-24 93-067 93-01-18 toga_flight12.mir The data are in IEEE 32-bit (floating point) words. Each logical record has 359 words. The blocking factor is 20 and hence each physical record has 28720 bytes (20 x 4 x 359).Each logical record contains one calibrated MIR scan comprising temporal, spatial and aircraft attitude information for the nadir position (beam position 29) of the scan followed by a brightness temperature value for each of 57 beam positions at all 6 MIR frequencies.
Logical Record Format word Parameter Source/Units GHz 1 Record Number 2 Month Real time clock (RTC) 3 Day Real time clock (RTC) 4 Hour IRIG 5 Minute IRIG 6 Second IRIG 7 Julian Day Navigation 8 Hour Navigation 9 Minute Navigation 10 Second Navigation 11 Latitude Degrees 12 Longitude Degrees (-West, +East) 13 Air Temperature Degrees celsius 14 Altitude Feet 15 Pitch Degrees (+ for nose down) 16 Roll Degrees (+ for roll right) 17 Heading Degrees 18- 74 57 brightness temperatures degrees Kelvin 90 75-131 150 132-188 183.3 +/-1 189-245 183.3 +/-3 246-302 183.3 +/-7 303-359 220
4.1 FTP AccessMIR Calibrated Brightness Temperatures (Binary files)
5. Data Quality Assessment
The data are geo-referenced (including altitude) based on the ER-2's Inertial Navigation System (INS). The noise threshold for the MIR is 1 degree Kelvin. Noise saturation did not occur during the TOGA-COARE campaign.Absolute calibration is performed every scan cycle by consecutively pointing the scan mirror at the hot (330 K) and cold (ambient air cooled) external calibration loads.
6. Points of Contact
- For information about or assistance in using any NASA/TOGA COARE data:
- GES DISC User Services
- Code 610.2
- NASA Goddard Space Flight Center
- Greenbelt, Maryland 20771
- GES DISC User Services
- 301 614-5224
- For detailed information about the sensor or data,
- Principal Investigator:
- James R. Wang
- Code 975
- NASA Goddard Space Flight Center
- Greenbelt, MD 20771
- Internet: wang@sensor.gsfc.nasa.gov
- (301) 286-8949 (voice)
- (301) 286-1761 (fax)
- Co-Investigator:
- Paul Racette
- Code 975
- NASA Goddard Space Flight Center
- Greenbelt, MD 20771
- Internet:per@meneg.gsfc.nasa.gov
- (301) 286-9114 (voice)
- (301) 286-1762 (fax)
- For MIR data processing information:
- Hugh Powell
- Code 971
- NASA Goddard Space Flight Center
- Greenbelt, MD 20771
- Internet: powell@snowmelt.gsfc.nasa.gov
- (301) 286-2310 (voice)
- (301) 286-1761 (fax)
7. References
7.1 Instrument/Data Processing DocumentationNASA/TOGA COARE Science Data Workshop II, Proceedings of a workshop held in Albuquerque, New Mexico, March 15-17, 1994, July 1994, FIRE Project Office, NASA Langley Research Center, Mail Stop 483, Hampton, VA 23666.ER-2 Flight Summary Report, NASA ER-2 Deployment, Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, Aircraft Data Facility, NASA Ames Research Center, Mail Stop 240-6, Moffett Field, CA 94035-1000
Mission Summary Reports, TOGA COARE, November 1993, NASA TOGA COARE Project Office, NASA Langley Research Center, Mail Stop 483, Hampton, VA 23666
7.2 Journal Articles and Study ReportsFalcone, V. J., K. Griffin, R. G. Isaacs, J. D. Pickle, J. F. Morrissey, A. J. Jackson, A. Bussey, R. Kakar, J. Wang, P. Racette, D. J. Boucher, B. H. Thomas, and A. M. Kishi, 1993: SSM/T-2 calibration and validation data analysis. Environ. Res. Papers, No. 1111, PL-TR-92-2293, Phillips Laboratory, Hanscom Air Force Base, MA 01731-5000.Racette, P., L. R. Dod, J. C. Shiue, R. F. Adler, D. M. Jackson, A. J. Gasiewski, and D. S. Zacharias, 1992: Millimeter-wave imaging radiometer for cloud, precipitation, and atmospheric water vapor studies. IGARSS'92, Houston, Texas, 1426-1428.
Wang, J. R. and L. A. Chang, 1990: Retrieval of water vapor profiles from microwave radiometric measurements near 90 and 183 GHz. J. Appl. Meteor., 29(10), 1005-1013.
Wang, J. R., S. H. Melfi, P. Racette, D. N. Whiteman, R. A. Kakar, R. A. Ferrare, K. D. Evans and F. J. Schmidlin, 1993: Simultaneous measurements of atmospheric water vapor with MIR, Raman Lidar and rawinsondes. IGARSS'93.
Home
- NASA Official: Steve Kempler
- Website Curator: Anthony Drake
- Last updated: February 25, 2009 16:25:23 GMT
