Millimeter Imaging Radiometer (MIR) Data from TRMM LBA

Sponsor

The distribution of these data sets is funded by NASA's Earth Science Enterprise. The data are not copyrighted; however, we request that when you publish data or results using these data, please acknowledge as follows:

Characteristics

The MIR data consist of calibrated brightness temperatures in degrees Kelvin at seven channels (89, 150, 183.3±1, 183.3±3, 183.3±7, 220, and 340 GHz).

The data is preliminary. Before using MIR data in your publication, please contact the Principal Investigator Dr. James Wang (wang@sensor.gsfc.nasa.gov).

File Formats

MIR data for each flight is contained in one file. The data are in four-byte IEEE floating point words.

Each logical record of size 2316 bytes( 4 x 579)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 7 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- 26 HouseKeeping Temperatures     27 Hot average temperature for this scan     28 Cold average temperature for this scan     29 Hot temperature, 8-scan moving average     30 Cold temperature, 8-scan moving average     31- 39 Hot average counts for this scan     40- 48 Cold average counts for this scan     49- 57 Hot counts, 8-scan moving average     58- 66 Cold counts, 8-scan moving average     67- 123 57 brightness temperatures degrees Kelvin 89 124-180 150 181-237 183.3 ±1 238-294 183.3 ±3 295-351 183.3 ±7 352-408 220 409-465 340 466-522   523-578   NOTE: The last 2 words in the record are zero-filled

File Naming Convention

                OUT.yyddd.MIR
 where:
              yy = year
             ddd = day of year 
             MIR = instrument name

Example: File for 23 January, 1999              
                OUT99023.MIR

Companion Software

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
! This program reads a few records of 1998 MIR data in SGI computer
! !!!!!!!!!!!!!!!!!!!!!***  last 3 channels have zero brightness temp.

      structure /OutStruct/
      real*4   		RecNumber
      real*4   		RTCmonth, RTCDayOfMonth
      real*4   		IrigHour, IrigMin, IrigSec
      real*4   		NavJulian, NavHour,  NavMin,  NavSec
      real*4		latitude, longitude
      real*4		AirTemp, altitude, pitch, roll, heading
      real*4            HouskptTmp(9)
      real*4            HotTemp,CldTemp,HotTemp8a,CldTemp8a
      real*4            HotCnt(9) ,CldCnt(9) ,HotCnt8a(9),CldCnt8a(9)
      real*4   		BrightTemps(9,57)
      end structure

      record/OutStruct/ i
      record/OutStruct/ j

      integer   m, k
       ib=    1
       ie=11111

      open(8, file='/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
     $ access='DIRECT', status='OLD', err=1999, recl=579*4)
c!!! use f77 -bytereclen !!!!

CCC   do m=   1, 11111
      do m=1,2
         read(8, rec=m, end=500, err=400) j
          call FLIP(j,i,579*4)


ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
       if( m.ge.ib.and.m.le.ie) then
       write(*,1)i.RecNumber,i.RTCmonth,i.RTCDayOfMonth
     @,i.IrigHour, i.IrigMin,i.IrigSec
     @  ,i.latitude,i.longitude,i.altitude ,i.pitch,i.roll,
     @i.heading,(i.BrightTemps(k,29)   ,k= 1,6)     


       endif
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
      end do
      stop 'Done!'
 400  call perror('Error reading record')
      stop 3
 500  call perror('Hit EOF reading record')
      stop 4
 1999 call perror('Error opening input file!')
      stop 5
  1    format( f6.0,1x,2f3.0,f3.0,f4.0,f4.0,2f6.1,f7.0,12f6.1)
  4    format( 3x ,2f6.1,f9.0,9f6.1)
  2    format(   (10f6.1))                         
  3    format(1x,'NavJulian, hr,min,sec' ,8x,4f5.1)
      end
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
      subroutine flip(ib,jb,n)
      character*1 ib(n),jb(n)
       do k=1,n-3,4
        jb(k  )=ib(k+3)
        jb(k+1)=ib(k+2)
        jb(k+2)=ib(k+1)
        jb(k+3)=ib(k  )
       end do
      return
      end
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

FTP Site

MIR Calibrated Brightness Temperatures(Binary files)

or directly via FTP at

ftp disc2.nascom.nasa.gov

login: anonymous

password: < your internet address >

cd data/trmm-lba/aircraft/er-2/mir/

Points of Contact

Technical Inquiries about this Data should be addressed to:

Principal Investigator:

James R. Wang

Code 975

NASA Goddard Space Flight Center

Greenbelt, MD 20771

Internet: wang@sensor.gsfc.nasa.gov

(301) 614-5655 (voice)

(301) 614-5558 (fax)

Co-Investigator:

Paul Racette

Code 975

NASA Goddard Space Flight Center

Greenbelt, MD 20771

email:per@meneg.gsfc.nasa.gov

(301) 614-5655 (voice)

(301) 614-5558 (fax)

For additional information, please contact the GES DISC User Services:

Instrument Characteristics

The MIR is nadir-oriented in the forward compartment of the right wing pod of the ER-2 aircraft. It scans in a plane perpendicular to the direction of flight with a swath of ± 50 degrees from nadir. At the ER-2 aircraft cruising altitude of about 20 km, the footprint at nadir is about 1km. The speed of aircraft is about 200 m/sec. With a scanning cycle of about 3 seconds, MIR produces continuos images at all nine channels with a ground swath of about 42 km. Each scan takes 3 seconds and produces 57 brightness temperature values for all nine channels.

              
                      
                    Accuracy   : ±2 Kelvin
                                      
                    Precision  : 0.5 Kelvin
                                      
               Angular Swath   : ±50 
                                      
                   Beamwidth   : ~ 3 dB (independent of frequencies)
                                      
               Response Time   :  ~40 msec
                                     
                      Weight   : ~180 lbs
                                      
                       Power   : ~400 watts
                                      
                     Platform  : ER-2 aircraft (at ~20 km altitude)
                                      
                     Location  : Right front wing pod
                                      

Data Quality Assessment

The data are geo-referenced based on the ER-2's Inertial Navigation System (INS). Absolute calibration is performed every scan cycle by consecutively pointing the scan mirror at the hot (at 330 K) and cold (at ambient air cooled) external calibration targets which are closely monitored to within ±0.1 K.

Wang, J.R., S.H. Melfi, P. Racette, D.N. Whitemen, L.A. Chang, R.A. Ferrare, K.D. Evans and F.J. Schmidlin; Simultaneous measurements of atmosperic water vapor with MIR, Raman lidar and rawinsondes., J.Appl.Meteor., 34(7) 1595-1607, 1995.

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.

Falcone, 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.