TITLE:  Desert Research Institute (DRI) Mobil Microwave Radiometer (MMR)

AUTHORS:

       PIs: David E. Kingsmill and Huaqing Cai
       Email: davidk@dri.edu, caihq@dri.edu
       Phone:  (775) 674-7071
       FAX:    (775) 674-7007
       Mailing Address:
       Atmospheric Science Center
       Desert Research Institute
       2215 Raggio Parkway
       Reno, NV  89512-1095

1.0 DATA SET OVERVIEW:
       
       The Desert Research Institute (DRI) Mobile Microwave Radiometer (MMR) provides
       measurements of total water vapor and liquid water in the atmosphere. Surface
       temperature, relative humidity, vehicle location and time are also recorded.
       
       Data Set Overview:
       DATE         MISSION    TIME(UTC)    COMMENTS
       May 22, 2002   CI       1500--0050   Data recoverable, available upon request
       June 1, 2002   CI       1930--2100
       June 2, 2002   CI       1730--2100
       June 3, 2002   CI       1810--2345
       June 7, 2002   ABL      1545--2125
       June 9, 2002   CI       1855--2250
       June 10,2002   CI       1825--2230
       June 11,2002   CI       1610--2320
       June 12,2002   CI       1725--2155
       June 14,2002   BLE      0950--1855
       June 15,2002   CI       1540--2150
       June 18,2002   CI       1755--2345
       June 19,2002   CI       1810--2325
       June 21,2002   BLE      1030--1905
       June 25,2002   BLE      1025--2020

2.0 INSTRUMENT DESCRIPTION:

      The Desert Research Institute (DRI) Mobile Microwave Radiometer (MMR) is a dual-channel
      instrument that operates at frequencies of 20.6 and 31.65 GHz. The basic antenna and receiver
      components have been thoroughly described in previous work, particularly Huggins (1995) and
      Hogg et al. (1983). The instrument measures brightness temperature at each frequency, from 
      which absorption is computed. Statistical retrieval techniques are used to compute
      path-integrated depths of water vapor and liquid water (Westwater and Strand 1972; Hogg et al.
      1983). The atmospheric retrieval coefficients are computed using a radiative transfer model
      on a set of historic soundings relevant to the location of interest.

      For detailed information of DRI MMR, please refer to IHOP webpage at:
      http://www.atd.ucar.edu/dir_off/projects/2002/IHOPinst/dri_mmm.pdf

3.0 DATA COLLECTION AND PROCESSING:

      The Mobile Microwave Radiometer (MMR) did numerous transects of the targeted boundaries
      during each CI mission. Pre-defined legs were sampled during each BLE and ABL mission.
      The total water vapor and liquid water are derived using a statistical retrieval method.
      Possible radio interferences are flagged as -999.0 in the data set. No data
      intercomparisons have been performed.

4.0 DATA FORMAT:

    Data File Name Convention: DRIMMR_YYMMDDHHMM.txt
    where YYMMDDHHMM specifies the start time of data collection.

    Each data file contains a header and a number of data records.
    An example of a header looks like :
 
    PI/DATA CONTACT=David Kingsmill, Huaqing Cai
    DATA COVERAGE=Start:2002-06-01 19:44:04; STOP:2002-06-01 21:21:51
    PLATFORM/SITE=Ground Based Mobile Facility
    INSTRUMENT=Desert Research Institute Mobile Microwave Radiometer
    COORDINATES=Mobile
    DATA VERSION=1.0 ( 30 OCT 2002) PRELIMINARY
    REMARKS=IHOP 2002
    REMARKS=Bad values are flagged as -999.0, no intercomparisions are performed
    yyyy-mm-dd HH:MM:SS     LAT      LONG     Temp   RH     Vapor  Liquid  Temp_QC RH_QC Vapor_QC Liquid_QC
       UTC                  Deg      Deg       C     %       cm      mm      C       %      cm      mm

    
    The data record format is column delimited ASCII format. Both original and quality-controlled
    values of temperature, relative humidity, water vapor and liquid are recorded in the same
    data record. The original temperature, relative humidity, water vapor and liquid are represented
    by Temp,RH,Vapor and Liquid, while the quality-controlled temperature, relative humidity,
    water vapor and liquid are represented by Temp_QC, RH_QC, Vapor_QC and Liquid_QC, respectively.
    An example of one data record is shown below:
    2002-06-01 19:44:04   36.6163 -101.0932   34.3   18.6    2.12   -0.13   34.3   18.6    2.12    0.00

    Where each column is corresponding to one parameter listed in the file header.

    This is data version 1.0 released on 30 OCT 2002. The bad values are flagged as -999.0

5.0 DATA REMARKS:
    
    (a) No intercomparision with other instruments has been done.
    (b) The temperature and humidity observations should be viewed with caution
        when the radiometer truck is stopped since those sensors need proper ventilation.
    (c) Extremely high values of water vapor and liquid water content just before convection
        initiation should also be treated with caution although no flag is assigned to those values.

6.0 REFERENCES:

     Please refer to IHOP webpage at:
     http://www.atd.ucar.edu/dir_off/projects/2002/IHOPinst/dri_mmm.pdf
     for all the references cited in this file.