MAPCHECK(1)

NAME
mapcheck - examine fine-scale land-sea database

SYNOPSIS
mapcheck r lat long dist

mapcheck h lat long

mapcheck o lat long

DESCRIPTION

The program mapcheck is designed to read from the fine-scale land-sea data file to allow the user to examine what this file shows in the vicinity of a particular point. Since this file is used to determine the distribution of the tide close to a station for loading computations, the accuracy of it can be important. The file (which is hardwired into the program with the name lndsea.dat) must be present in the directory in which the program is being run. The program has three options, all of which require that station coordinates (latitude and longitude) be included on the command lines. The options are:

r   Write to standard output a rough ``printer-plot'' of the land and sea distribution within a distance dist of the station; dist should be in kilometers. In this plot, - means land.

r   Write to standard output a ``printer-plot'' of a 1° by 1° area to show the local structure of the land-sea file. The lower left corner of the area will be at the integer latitude and longitude closest to the values given on the command line. The file has a resolution of 1/64° and what is shown is a plot with 64 by 64 points; each point in the file thus corresponds to 1 ``pixel'' of the database.

o   The program writes out the distance to the nearest ocean from the point specified on the command line.

DATA FILE

The data file is a binary representation of the land-sea distribution of the entire world, based on the version created from the World Vector Shoreline for Version 3 of the GMT mapping tools. See the supplementary documentation to the loading programs for more details.

AUTHOR
D. C. Agnew