miedr [ inputfile ... ] There are no parameters.
miedr derives geophysical parameters from the SSM/I TeraScan datasets output by the DMSP special sensor ingest functions rdsin and rtdin. miedr implements the Air Force Global Weather Center (AFGWC) D-matrix algorithm to compute quantities such as wind speed, rain rate, and total atmospheric water vapor and cloud water over the ocean; surface temperature, soil moisture, and snow depth over land, and ice edge, concentration, and age.
The named input files must be SSM/I TeraScan datasets output from the DMSP ingest functions rtdin and rdsin. Thus, the input filenames must have the suffix ".mi_s", meaning SSM/I sensor dataset. Output filenames are generated to have the same form as the input filenames, except with the suffix ".mi_e", meaning SSM/I environmental dataset. The output datasets contain 12 two-dimensional variables at the same spatial resolution as the 19-37Ghz channels of the SSM/I input data. These variables, their data types and units are:
surface_type byte
wind_speed short m/s
cloud_water short kg/m2
water_vapor short kg/m2
rain_rate short mm/hr
rain_flag byte
soil_moisture short millimeters
surf_temp short kelvin
snow_depth short millimeters
ice_concen short percent
ice_age byte
edge byte
The surface_type values denote the following:
LAND 0
VEGETATED LAND 1
ARTIC 2
ICE 3
POSSIBLE ICE 4
OCEAN 5
COAST 6
FLOODS 7
DENSE VEGETATION 8
VEGETATED LAND 9
DRY ARABLE SOIL 10
MOIST ARABLE SOIL 11
SEMI-DESERT 12
DESERT 13
RAIN OVER VEGETATION 14
RAIN OVER SOIL 15
WATVEG 16
WET SOIL 17
DRY SNOW 18
WET SNOW 19
REFROZEN SNOW 20
The rain_flag indicates the degree atmospheric conditions (generally rain) may be contaminating the wind_speed retrievals over the ocean. Values range between 0 and 3, with 0 indicating no contamination, and 3 indicating the greatest contamination.
rain_flag wind_speed error (m/s)
0 < 2
1 2-5
2 5-10
3 > 10
The ice_age variable specifies whether locations indicating ice are first-year or multi-year ice. First-year ice is indicated by the value 1, and multi-year ice is indicated by the value 2.
The edge varible indicates where snow and ice edges are located. Snow edges are indicated by the value 1, ice edges by the value 2, and locations that are both snow and ice edges have the value 3.
./terascan/refdata/ssp/af_surf.tdf ./terascan/refdata/satel/f-*/midmatrix.tdf
dmsp, ols, ssmi, rtdin, rdsin, t1edr, geoph, t2edr, datasets.
SSM/I Program Maintenance Manual, Manual for FNOC, (Rev B), Volume III, CDRL Item No. 013A1, March 1991.
Last Update: $Date: 1998/05/29 18:42:33 $