Millimeter Imaging Radiometer (MIR)

MIR instrument was flown on the NASA ER-2 aircraft over Texas from April 9 through May 6, 1998 for the TEFLUN-A experiment and over Florida from August5 through September 27, 1998 for the TEFLUN-B & CAMEX-3 field campaigns. MIR is an airborne cross-track-scanning radiometer that provides calibrated brightness temperatures at nine different channels in the band 85-340 GHz. It is being used aboard NASA's high-altitude (21 km) ER-2 to study atmospheric water vapor, clouds, rain, and other forms of precipitation. The MIR measurements were made under the direction of the NASA/GSFC scientists Dr. James Wang (Principal Investigator) and Dr. Paul Racett (co-investigator)and the data sets are archived at the Goddard Data and Information Services Center (DISC).

Sponsor

Characteristics

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

File Format

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 9 MIR frequencies.

File Naming Convention

                teflunb_mir.yymmdd.jjj.ssssss.bin
 where:
          yymmdd = year, month & day
             jjj = Julian day 
          ssssss = Aircraft sortie number
             bin = file type designation, binary

Example: File for 21 April, 98              
                teflunb_mir.980421.111.98-048.bin

Companion Software

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
! 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
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

FTP Site

MIR Calibrated Brightness Temperatures(Binary files)

MIR Browse Images

or directly via FTP at

ftp disc2.nascom.nasa.gov

login: anonymous

password: < your internet address >

cd data/TEFLUNB/aircraft/nasa_er2/mir/

Hydrology Data Support Team
email: hydrology@disc.gsfc.nasa.gov

Technical Inquiries about this Data should be addressed to:

MIR Data Investigators:

For detailed information about the sensor or data,

Principal Investigator:

Dr. 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)

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
                                      

Algorithm

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.