Scales, Projections, etc

Scales, Projections, Distances, Triangulation, Grids, Latitude and Longitude

Coordinates, Grids, Datums, Projections (see also Ordnance Survey section):

• ArcGIS Desktop - List of Supported Map Projections. Brief descriptions and illustrations.

• Blue Marble Geographics. Coordinate conversion software and map data. Mostly for purchase though a few products are free.

• The "Coordinates Translator". Conversion from "British Modified System" coordinates, for example LZ1/vX962494, towards more "conventional" geographical coordinates (Latitude/Longitude).

• GPS Utility. The program converts between different map datums and many coordinate formats (Lat/Long, UTM/UPS, country grids etc.).

• Grids & Datums. Articles published by the American Society for Photogrammetry & Remote Sensing. Each article covers a different country.

• IOGP Geodesy Subcommittee of the Geomatics Committee. Maintains a list of coordinate systems in use round the world - the EPSG Geodetic Parameter Dataset (a collection of definitions of coordinate reference systems and coordinate transformations which may be global, regional, national or local in application) at www.epsg.org/.

• Latitude and Longitude Lookup. Links to other web sites for looking up or finding your latitude and longitude. Also a Decimal to Minutes-Seconds converter.

• Map Projections. Lots of useful information. The site was inspired by a seminar in map projections in the Geography Department, Hunter College, City University of New York.

• Map Projections. Compiled by Paul B. Anderson a member of the International Cartographic Association's Commission on Map Projections.

• Map Projections: a working manual. By John Snyder. Available to download.

• MapTools. Provides GPS users with the tools and knowledge to fully utilize geographic coordinates. MapTools produces grids, corner rulers, roamers, and rulers to assist with plotting or measuring positions on many different scales of maps, some of which can be downloaded for free.

• Mapthematics.com - Geocart Projections. Descriptions and illustrations of a range of projections.

• NeoProgrammics.com. Compute the exact value of the obliquity of the ecliptic (and therefore the positions of the Tropics and the Polar Circles) for any given date.

• Picture Gallery of Map Projections. Compiled by the Research Group, Differential Geometry and Geometric Structures.

• MapRef. The Internet Collection of MapProjections and Reference Systems in Europe by Stefan A. Voser.

• Octahedral Butterfly Map of the World. First published in 1909 by Bernard J.S. Cahill this website presents some of Cahill's articles, papers, and Butterfly map variants, which he continued to develop during four decades until 1940.

• The World Coordinate Converter (TWCC). A tool to convert geodetic coordinates in a wide range of reference systems. May require a download. For old site click here.

Distance Calculators:

• Free Map Tools. Measure distances, areas and find out which part of the other side of the earth is directly below you! Global tools plus couhtry specific ones, including tools using and finding UK postcodes.

• Great Circle Distances. Use the 'Calculate the distance between two addresses' section of this site to produce a map of the great circle distance between two locations. The site also has a 'Coordinate Converter', a 'Draw range rings around a point' feature and a 'Find the coordinates at a given distance and bearing' feature.

• MapCrow. Travel distance calculator.

• Surface Distance Between Two Points of Latitude and Longitude AND Great Circle Distances Between Cities.

• Time and date.com. Find the distance between selected cities or locations.

Scales and Measurements :

• Convert-me.com. Interactive distance and length conversion for old and new units from around the world.

• Dictionary of Units of Measurements. Compiled by Russ Rowlett.

• Map History / History of Cartography. Lists some useful sites.

• Map Scales Fact Sheet from USGS. Fact Sheet 015-02.

• MapTools Scale Calculator.

• Mathematical data for bibliographic descriptions of cartographic materials and spatial data (on WayBack machine). Was maintained by Jan Smits. Includes projections and meridians as well as Geoff Armitage's Conversion Table of Measurements. 

• Measurement Conversion Factors. Conversion factors for old measurement terms that may have been used in the Châteauguay Valley, Québec.

• Measuring Worth. Calculate the worth of monetary transactions over time.

• Metric Conversions. Temperature, length, area, volume and weight/mass unit conversions with both online calculators and printable tables.

• Online Conversion.com. Length and distance, plus many others.

• Scale Buddy. Scale calculation tool from Business Map Centre. No need to download.

• Scale Calculator. Inches, centimeters and miles. From Terry Reese.

• ScaleFinder (and lots of other free GIS and mapping tools from Free Mapping Tools by Nigel James). Download the software ONTO YOUR OWN PC! Converts linear scales to representative fractions and vice-versa. Free to non-commercial users.

• Guide to Map Scale. From the University of Arizona.

 Ordnance Survey, Trig Points, Accuracy, etc.:

• Boundary Problems Website. Includes section on map accuracy and others on rights of way and boundary ownership.

• Online Conversion.com. Convert to and from OS Grid used in the UK and Latitude/Longitude. Also many other conversions.

• Convert Modified British System, Military Grid, War Office Grid, Cassini Grid to National Grid.

• The Defence of East Sussex Project has some background information.
• Straight to the point right on time. From: Regional Historian, Issue 5, Summer 2000, published by the Regional History Centre, University of the West of England. (Opens as a pdf so may not open properly on the Map Room PC). Summary of a Royal Engineer’s formula for converting Cassini grid references with an accuracy of +/- 200 mtrs.
• The "Coordinates Translator". Conversion from "British Modified System" coordinates, for example LZ1/vX962494, towards more "conventional" geographical coordinates (Latitude/Longitude). More information available here and here.
• FieldenMaps.info. Includes a co-ordinate converter for OS and other maps.FieldenMaps.info. Includes a co-ordinate converter for OS and other maps.

• Nearby.org.uk. Geographical Search Engine for all things to do with UK and Ireland Mapping plus OS trig sources, web mapping site comparison table and an online World co-ordinate Converter.

• Ordnance Survey Website. See, for example: Benchmark locator, Geodesy and Positioning. 

• Triangulation Pillar Waypoints. (Ordnance Survey). Includes links to other sources of information on Trig Pillars.

• TrigTools. Data-Mining Triangulation, Levelling and Geospatial Data. Includes information on Irish trig points.

• UK Grid Reference Finder. Search by location, post code, grid reference or latitude and longitude. Hover over pins on map, or right click on map, to find location, post code, grid reference or latitude and longitude of locations. See location as a map, aerial view of bird's eye view.