EPSG:6637 NAD83(MA11) / Guam Map Grid
Projected system (Transverse Mercator) in use: Guam - onshore. The full definition below, and conversion in one click.
EPSG publishes no simple transformation to WGS 84 for this datum: conversion works on the ellipsoid alone and can be off by tens of metres.
| Code | EPSG:6637 |
|---|---|
| Name | NAD83(MA11) / Guam Map Grid |
| Type | Projected system — Transverse Mercator |
| Area of use | Guam - onshore |
| Bounds | W 144,58° · S 13,18° · E 145,01° · N 13,70° |
| Countries | Guam |
| Datum | NAD83 (National Spatial Reference System MA11) |
| Ellipsoid | GRS 1980 a = 6378137 m · 1/f = 298.257222101 |
| Base geographic system | EPSG:6325 — NAD83(MA11) |
| Unit | metre (X east, Y north) |
| Transformation to WGS 84 | No simple transformation published (ellipsoid alone) |
| Scope | Cadastre, engineering survey, topographic mapping (large and medium scale). |
Projection parameters
| Parameter | Value | Unit |
|---|---|---|
| Latitude of natural origin | 13.5 | degree |
| Longitude of natural origin | 144.75 | degree |
| Scale factor at natural origin | 1 | unity |
| False easting | 100000 | metre |
| False northing | 200000 | metre |
proj4 definition
+proj=tmerc +lat_0=13.5 +lon_0=144.75 +k=1 +x_0=100000 +y_0=200000 +ellps=GRS80 +units=m +no_defsPaste it into QGIS, proj4js, PostGIS (spatial_ref_sys) or GDAL. +towgs84 carries the EPSG transformation to WGS 84; the official code stays EPSG:6637.
WKT (ESRI format, the .prj content)
PROJCS["NAD_1983_MA11_Guam_Map_Grid",GEOGCS["GCS_NAD_1983_MA11",DATUM["D_NAD_1983_MA11",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",100000.0],PARAMETER["False_Northing",200000.0],PARAMETER["Central_Meridian",144.75],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",13.5],UNIT["Meter",1.0]]Other systems — Guam
Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.