Documentation for Land And Water Masks
This dataset contains land and water masks for the 48 conterminous
United States, extracted from the "Conterminous United States AVHRR
Companion Disc" CDROM, distributed by the USGS EROS Data Center
(EDC).
The data are in raster format, with a raster spacing of 1 km and raster
dimensions of 2889 lines (rows) by 4587 samples (columns). Two versions
of the mask are available, as follows:
| land_mask.bsq.gz
| Array of 8-bit (1-byte) binary integers having value 1 for
land and 0 for water
|
| water_mask.bsq.gz
| Array of 8-bit (1-byte) binary integers having value 1 for
water and 0 for land
|
The two .bsq.gz arrays are stored in the database in GNU
gzip (compressed) format. Each file is accompained by an LAS
.ddr file, which contains raster size and georeferencing
information. Note that the .bsq format is identical to the LAS
.img format.
- Projection parameters:
| Name: | Lambert Azimuthal Equal Area
|
| Projection units: | meters
|
| Spheroid: | sphere of radius 6,370,997 meters
|
| Central longitude: | -100° (W)
|
| Central latitude: | 45° N
|
| False easting: | 0
|
| False northing: | 0
|
-
Bounding coordinates:
- Projection --
- -2050500 to 2536500 easting
- 752500 to -2136500 northing
- Geographic (approximate) --
- -128° to -65° longitude
- 51° to 23° latitude
Cell size for gridded data: 1 km by 1 km.
Grid dimensions: 2889 lines (rows) of 4587 samples (columns) each.
Last change: 1998 May 7,
R. A. White / raw@essc.psu.edu