L2_CC_Browse_Subset Interface Specification

Interface Specification Version 2.1.5.2

June 4, 2001

Swath Name = "L2_CC_Browse_Subset"

Level = "level2"

# Footprints = 30

# scanlines per scanset = 1

Dimensions

These fields define all dimensions that can be used for HDF-EOS swath fields.

The names "GeoTrack" and "GeoXTrack" have a special meaning for this document: "Cross-Track" data fields have a hidden dimension of "GeoXTrack"; "Along-Track" data fields have a hidden dimension of "GeoTrack"; "Full Swath Data Fields have hidden dimensions of both "GeoTrack" and "GeoXTrack".

Name Value Explanation
GeoXTrack 30 Dimension across track for footprint positions. Same as number of footprints per scanline.
GeoTrack # of scan lines in swath Dimension along track for footprint positions. Same as number of scanlines in granule. (Nominally 45 for Level-2, AMSU, and AIRS/Vis low-rate engineering; 135 for AIRS/Vis and HSB high-rate quantities)

Geolocation Fields

These fields appear for every footprint (GeoTrack * GeoXTrack times) and correspond to footprint center coordinates and "shutter" time.

Name Explanation
Latitude Footprint boresight Latitude in degrees North (-90.0 ... 90.0)
Longitude Footprint boresight Longitude in degrees East (-180.0 ... 180.0)
Time Footprint "shutter" TAI Time: floating-point elapsed seconds since Jan 1, 1993
Size: 32400 bytes (0.0 MB) per 45-scanset granule

Along-Track Data Fields

These fields appear once per scanline (GeoTrack times)

Name Type Extra Dimensions Explanation
scan_node_type 8-bit integer None 'A' for ascending, 'D' for descending, 'N' for North-Polar, 'S' for South-Polar
Size: 45 bytes (0.0 MB) per 45-scanset granule

Full Swath Data Fields

These fields appear for every footprint of every scanline in the granule (GeoTrack * GeoXTrack times)

Name Type Extra Dimensions Explanation
scanang 32-bit floating-point None Scanning angle of AIRS instrument for this footprint (-180.0 ... 180.0)
quality_flag 32-bit integer None Quality Flag (TBD)
AIRS_T_200mb 32-bit floating-point None Radiance of AIRS Temperature sounding channel at 200 mb (milliWatts/m**2/cm**-1/steradian)
AIRS_O3 32-bit floating-point None Radiance of AIRS ozone channel (milliWatts/m**2/cm**-1/steradian)
AIRS_Window 32-bit floating-point None Radiance of AIRS "window" (surface) channel (milliWatts/m**2/cm**-1/steradian)
AIRS_CH4 32-bit floating-point None Radiance of AIRS methane channel (milliWatts/m**2/cm**-1/steradian)
AIRS_H2O 32-bit floating-point None Radiance of AIRS water channel (milliWatts/m**2/cm**-1/steradian)
Size: 37800 bytes (0.0 MB) per 45-scanset granule

Total File Size (plus storage for dimensions and other HDF-EOS overhead): 70245 bytes (0.1 MB) per 45-scanset granule = 16.9 MB per day