lsmask [ parameter=value ... ]
Parameters are: operation, master_file, mask_database, master_var, mask_var.
lsmask can perform three operations on the landmask database: intitialization, update, and retrieval. The initialization operation creates the database file and assigns every pixel of the earth surface to water. The update operation takes the land/sea mask from the master file master_var variable to update the database. Retrieval generates the land/sea mask for the master_var master image and saves it to the mask_var into the same master file. master_var and mask_var have to be different.
Retrieval is the normal mode of operation. The other modes should be used with great caution.
The Land/Sea database has .01 deg resolution for both latitude and longitude.
To update the land/sea database, the master has to be either in the rectangular or in the mercator map projection. Retrieval can be performed for any projection; however, retrieval runs much faster for the rectangular or mercator projections.
OPTIONAL. One of the three operations described above.
Valid responses are [create update retrieve]. The default is retrieve.
Only if operation is not create. Either an input file with the land/sea mask (operation=update) or the output file to save the retrieved land/sea mask to (operation=retrieve).
Valid response is any TeraScan dataset that contains an Earth transform. The default is Master.
Only if operation is not create. Either the master file variable with the land/sea mask (operation=update) or the master file variable to be cloned into the mask_var to save the retrieved land/sea mask to (operation=retrieve).
Valid responses is any image variable from the master_file. There is no default.
Only if operation=retrieve. The new master file variable with the land/sea mask cloned from the master_var to save the retrieved land/sea mask to.
Valid responses is any name. There is no default.
The name of a Land/Sea database stored under $REFDATA/bathy directory.
The default is landmask.wdb2.
[1] lsmask master_file : char(255) ? [Master] mask_database : char(255) ? [landmask.wdb2] master_var : char(255) ? [master] mask_var : char(255) ? [lsmask] Master master lat/lon: [-13.90 57.90] x [-108.72 -31.28] Check Lat/Lon: [5790 -1390] x [-10872 -3128] landmask.wdb2: loading database ... Master: writing lsmask ...
refdata/bathy/landmask.wdb2
Last Update: $Date: 1999/05/10 20:14:47 $