Geographical Formats Understood by GPSS

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This chapter is a re-organization of the material you can find under "1.3 Formats for Geographic Position" in the GPSS Web page for adding maps.

In general, place locations in gazetteers and in GPSS files are expressed in a couple of ways, with variations in each of the two:

1.

Latitude/longitude (lat/long)

2.

Grid

Latitude is expressed as North or South of the Equator.

Longitude is expressed as West or East of Greenwich, England.

If you're interested, there is more discussion in this help file of coordinate notation types in the "From Your Source Geography to GPSS" topic.

Lat/Long Formats
In GPSS, Latitude and longitude are expressed in degrees and minutes with decimal fractions; or degrees and decimal fractions of degrees.

Type Example Description 15-character WGS84 523075N0073075W Recommended Lat: first 2 characters = degrees, next 2 = minutes, last 2 = decimal of minutes Long: first 3 characters = degrees, next 2 = minutes, last 2 = decimal of minutes This example is 52 degrees, 30.75 minutes North by 7 degrees, 30.75 minutes West WGS84 Degree/Decimal +52.575000 -007.575000 NOTE space in center and mathematical signs +/- Lat: minus (-) denotes south, plus (+) denotes north; first 2 characters = degrees, last 6 = decimal of degrees Long: minus (-) denotes west, plus (+) denotes east; first 3 characters: degrees, last 6 = decimal of degrees A favorite of US gazetteers and Microsoft Streets & Trips Note that GPSS requires the mathematical plus or minus sign before each expression. 17-character WGS84 5230750N00730750W Lat: first 2 characters = degrees, next 2 = minutes, remainder = decimal of minutes Long: first 3 characters = degrees. next 2 = minutes, remainder =decimal of minutes This example is 52 degrees 30.750 minutes North by 7 degrees 30.750 minutes West NOTE: for GPSS V4.94 and later

Grid Formats
Grid systems are the convention in the U.K. and a few other areas. The following are the grid types recognized by GPSS.

Type Example Note UK grid, 1m precision SU 12345 67890 Spaces before digit groups UK grid, 100m precision SU1234578 UK grid by X and Y 412.3,167.8 Comma (no spaces) between groups Irish grid, 1m precision A 12345 67890 Spaces between digit groups Irish grid, 100m precision A123456 18-character UTM grid 32U 012345 0067890 Spaces between digit groups 16-character UTM grid 32U01234500678 Not recommended 12-character UTM grid 32U012300678 Singapore Grid 123456

By Dave Gehman
© Copyright 2004, Robin Lovelock
Send changes, suggestions to Dave Gehman