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This page describes the LP DAAC MOD HDF-EOS2 and HDF4 files.
The swath files use dimension maps so users need to either find the corresponding geolocation HDF-EOS2 files or calculate the latitude/longitude based on dimension map parameters.
The size of dimension varies in geolocation fields and data fields.
For example, for the file MOD11_L2.A2007278.0350.005.2007280073443.hdf, the dimension size of geolocation fields is 406 (Coarse_swath_lines_5km) by 271 (Coarse_swath_pixels_5km), while the dimension size of data fields is 2030 (Along_swath_lines_1km) by 1354 (Cross_swath_pixels_1km).
The following table summarizes the information collected for the Swath files:
| File type | File size(avg.) | Geolocation Field | Datafield Dim. Range | CF-compliant information | Other special issues |
|---|---|---|---|---|---|
| HDF-EOS2 (Swath) |
4MB | Lat/Lon = 2D | 2D | Both geolocation fields and data fields have 'units' and 'long_name' attributes. | Files have dimension map. |
The projections of them are Geographic (GEO) or Sinusoidal (SNSOID). The following table summarizes the information collected for the Grid files:
| File type | File size(avg.) | Number of grid | Has lat/lon | Projection | Datafield Dim. Range | CF-compliant information | Other special issues |
|---|---|---|---|---|---|---|---|
|
HDF-EOS2
(Grid) |
330KB -1.54GB | 1 or 2 | No | GEO, or SNSOID* | 2D - 4D | Data fields have 'units' and 'long_name' attributes. | Some files contain objects and attributes that are added by the HDF4 APIs. |
The following table summarizes the information collected for the HDF4 files:
| File type | File size(avg.) | Datafield Dim. Range | CF-compliant attributes information | Other special issues |
|---|---|---|---|---|
| HDF4 | 5MB | 1D, 2D | Geo fields and some data fields have both 'units' and 'long_name' attributes. | FP_latitude and FP_longitude, which are equivalent to latitude and longitude, have unlimited dimensions (zero length in the current files). |
To retrieve sample MOD files and read the detailed description of these files, please click here.