ONLIne tools and definitions
This page contains links to resources and tools for interpreting maps and measuring the Earth's surface
General Information | Grids | Latitude/Longitude & Distances | Projection | Scale
General information - Click on an arrow 
to go to a link
Map History/History of Cartography: Measuring and Defining Space
From the Map History/History of Cartography site; contains links to resources
on distance; longitude, latitude and Prime Meridians; map projections; mountains;
and scale
National Geodetic Survey Geodetic Tool Kit
An online interactive computation of geodetic values; includes
links to a variety of conversion utililities
Grids - Click on an arrow
to go to a link
The Public Land Survey System (PLSS) (article from the National
Atlas)
All lands in the public domain are subject to subdivision by this rectangular
system of surveys, regulated by the U.S. Department of the Interior, Bureau
of Land Management (BLM); this article tells the history of the PLSS and
explains how it works
The State Plane Coordinate System (GIS Lounge)
The State Plane Coordinate System is a set of more than 100 different coordinate
systems using different projections; this article from the GIS
Lounge explains its origins and how it works
The State Plane Coordinate System (Virtual Terrain Project)
The State Plane Coordinate System is a set of more than 100 different coordinate
systems using different projections; this article from the Virtual
Terrain Project explains its origins and how it works
The Universal Transverse Mercator (UTM) Grid (USGS Fact Sheet 088-01,
August 2001)
Explains the Universal Transverse Mercator (UTM) Grid and how to determine
a UTM grid value for a map point
Latitude/Longitude & Distances- Click on an arrow
to go to a link
Latitude/Longitude Conversions
From the FCC, this utility permits the user to convert latitude and longitude
between decimal degrees and degrees, minutes, and seconds
NADCON NAD27 - NAD83 Coordinate Conversions
From the National Geodetic Survey's NADCON program, this utility allows
conversions between the NAD83 / WGS84 coordinate system and the older NAD27
coordinate system
Surface Distance Between Two Points of Latitude and Longitude/
Great Circle Distances Between Two Cities
Tools for calculating distance between two points on the Earth's surface
Projection - Click on an arrow
to go to a link
Map Projection Overview
An overview of map projection developed by Peter H. Dana, Department of
Geography, University of Texas at Austin, 1995, rev. 2000
National Geographic's Round Earth, Flat Maps
An overview of map projection created by National Geographic
U.S. Geological Survey Map Projections
An overview of the issues of map projection, which is used to portray all
or part of the round Earth on a flat surface; includes definitions and explanations
of a variety of commonly used projections
Scale - Click on an arrow
to go to a link
Bureau of Economic Geology's GIS Tools Online
Tools for converting various map-related measures; includes a scale calculator
Oregon State University Scale Calculator
Calculates American standard, metric and miscellaneous conversions
Map Scales (USGS Fact Sheet 015-02, February
2002)
An overview of map scales with a focus on common scales used by the U.S.
Geological Survey