UTMConvert Application for Ewe
Version 1.0*


Main UTMConvert Display UTMConvert is an application for Ewe enabled computers to convert Earth latitude/longitude encoded positions into universal transverse mercator (UTM) encoded positions, and vice versa.

To use this version of UTMConvert you must install a Ewe¹ VM (Virtual Machine) on your computer. Ewe is a version of Java which runs on a variety of desktop and handheld computers. It is very compact and efficient. It uses only about 2 Mbytes of memory.
To learn more about Ewe please read the introduction on the Bray Mobile Applications page.

UTMConvert displays the following data:

A detailed description of the entire display and its use is discussed below.

We hope you find UTMConvert a useful adjunct to your Mobile and Desktop applications.

About This Documentation

UTMConvert is intuitive and easy to use.
This documentation's size seems to be a contridiction, but you need to read it so that you know about "hidden" menus, and supporting files which contain UTM Datum and Location data.
For a Quick Start read Installation. Then after trying it out please return to this documentation to learn all of the features.


Since you are reading this documentation, you have found that there are two .zip archives in UTMConvert10.zip. The UTMConvert10Install.zip archive contains the files to be installed on your computer. The UTMConvert10Doc.zip contains this documentation you are now reading.

The first thing to do is to install the Ewe VM on your computer(s), if not already installed.
Follow the instruction found on the Ewe Download and Installation Page for your computer(s). The Ewe installer will create directories on your computer and put the Ewe VM files in them. After Ewe is installed find the Ewe directory. For example, in a Windows Desktop it will be where you told the installer to install it, and in the Pocket PC it will (probably) be in \Windows\StartMenu\Programs\Ewe.

There is no installer for UTMConvert.ewe. The files in the UTMConvert10Install.zip archive can be put in any directory of your choice. However it is recommended that you put them in the directory with the Ewe VM. Specifically the directory in which you find 'ewe.ewe'. This will make it easier to find them if you want to change them, and when you add additional applications from Bray Mobile Applications, common files can be shared. Specifically the Location Data CSV files.

Once you find the proper directory copy all of the files in UTMConvert10Install.zip into that directory, in what ever manner you do that on your computer.

Note: No matter what Regional settings are used on your computer(s), UTMConvert always uses the '.' (period) as the decimal point, the ':' (colon) as the hour/minute/second separator, and the ',' (comma) as the data separator.

UTMConvert should be ready to run now. Find UTMConvert.ewe with your File Explorer, click on it to try it out!

Using UTMConvert

UTMConvert Startup Display When you first open UTMConvert the main screen has no data defined.
Referring to the UTMConvert display at the right, you see:

The Menu Buttons are discussed last below.

Data Area

Data may be entered into the Latitude and Longitude boxes either manually or by using the Locations button. When the data is filled in by use of the Locations button the name of the location will be placed in the blank line above the Latitude box. Data entered manually cannot have a name entered.

Alternatively data can be entered into the UTM boxes manually.

When data entry is completed, pressing the Convert button will fill the in the corresponding converted data. That is, if data is entered into the UTM boxes, tapping Convert fills in the Latitude/Longitude boxes, and vice versa.

See: Latitude/Longitude Format Example below for the format for manual data entry.

Bottom Buttons

Refer to the bottom row of buttons from left to right:

See Supplied Location Data,   About Locations Data, and About Datum Data below for more information.

Menu Instructions

UTMConvert Menu Display The Menu button row has 3 menus:

More Details

Format Editing

There is one other way to change the Latitude/Longitude format. Tap and hold (or right mouse click) the Latitude or Longitude value. This will bring up three menu choices for the format of the value.

If you again tap and hold (or right mouse click) the Latitude or Longitude value a Cut/Copy/Paste menu will appear.

About Datum Data

There are literally hundreds of different UTM Datum. The ones supplied in the UTMConvert10Install.zip file, Datum.utm, contains a list 53 common UTM Datum. It is possible that you have a map with a different datum.
You can create your own datum -- read on.

Format of Datum.utm

You may have as many datum files as you like. Simply name them and use the extension .utm. For example: MyOldMaps.utm

Each line of the file is a datum entry. It consists of three entries separated by commas (','): The datum name, earth's equatorial radius in meters, the inverse of the flattening.

For example:
North America 1927 (U.S),6378137,298.257223532662

This North America 1927 datum is to be use with continental United States maps.
The earth's equatorial radius = 6378137.
The inverse of the flattening = 298.257223532662

The flattening f is defined as: (EquatorialRadius-PolarRadius)/EquatorialRadius.

So the PolarRadius is EquatorialRadius * (1-f).
Using the above datum:
PolarRadius = EquatorialRadius * (1-1/298.252235) =
PolarRadius = 6378137 * (1-0.003352810665) =
PolarRadius = 6378137 * 0.996647133 =
PolarRadius = 6356751.957

You can see the difference between EquatorialRadius and PolarRadius for this datum is 21385.04 meters.

Surf the Internet to find the definition for ones you want to add to your datum files.

New Datum Based On Other Datum

It is not unusual for datum to be defined in terns of other datum. For example, to define a datum for North American 1927 to be used with Alaska (Excluding Aleutian Islands) maps, the URL http://earth-info.nga.mil/GandG/datums/dtp/CountryNorthAmericaTable.html gives this following information.

Alaska (Excluding Aleutian Islands)

Reference Ellipsoids and Parameter Differences
Name DA(M) Df x 10^4
Clarke 1866 -69.4 -0.37264639

Where DA(M) is the EquatorialRadius correction, and Df x 10^4 is the flattening correction.

Working out North America 1927 (Alaska)
Clarke 1866 is:
      Clarke 1866,6378206.4,294.9786982

Corrected EquatorialRadius is 6378206.4 - 69.4 = 6378137

Corrected InverseFlattening computed as follows:
      Clark1866 f = 1/294.9786982 = 0.00339007530408852
Df * 10^4 correction is -0.37264639
Df correction is -0.37264639 * 10^-4 = -0.000037264639
Df is 0.00335281066508852
InverseFlattening is 298.257223532662

North America 1927 (Alaska),6378137,298.257223532662

Supplied Location Data

UTMConvert10Install.zip archive contains two Location Data CSV Files: NoAmerica.csv, and Europe.csv. The locations in these files have been collected from various sources. They are not very accurate and could even be incorrect, especially the time zone and daylight time settings.
These files are text files and thus may be edited by with any text editor. You should edit these files into a new one containing your favorite locations. When doing so check for accuracy.

The Location Data CSV Editor Application (LocEdit) is available at the Bray Mobile Applications page. LocEdit makes it easier to edit Location Data CSV files and more data is available. If you are intending to create your own personal Location Data CSV files it is recommended that you get LocEdit.

Documentation that comes with LocEdit has full details about a Location Data CSV file format.

The format of Location Data files is described next.

NOTE: Beware that CSV files are an acceptable format for Excel. However, DO NOT use Excel to create or edit them since all the latitude, longitude formats are not known to Excel and it will modify them incorrectly without giving an error message!

About Location Data

The Location Data allows you to select a location on the Earth for UTMConvert.

Having a file of locations is much easier than entering a location manually when you want different information -- especially for travelers.
The form of the Location Data has been chosen to allow it to be easily edited so that you can create and update your favorite locations collection them together into files.

The Location Data is defined in Comma Separated File (CSV) files. These files were first introduced in the Palm OS GeoDB application -- an application for defining and editing geographic Location Data for use with associated Palm OS applications.

The format for these files is as follows:

  • Each location record is defined on one line of an ASCII (text) file.
  • Each field of a record is separated by a ','. Thus the technical name 'Comma Separated Value'.
  • The field contents are as follows:
    1. Name
    2. Latitude -- Three possible formats
    3. Latitude Hemisphere -- N (Northern) or S (Southern), above and below the equator
    4. Longitude -- Three possible formats
    5. Longitude Hemisphere -- E (Eastern) or W (Western), east or west from Greenwich
    6. Elevation -- Application defined units (not used in UTMConvert)
    7. Time Zone -- Three possible formats (not used in UTMConvert)
    8. Time Zone Hemisphere -- E (Eastern) or W (Western) (not used in UTMConvert)
    9. Daylight Time Code -- Digit (not used in UTMConvert)

    Example: Potsdam NY,44:38.562,N,75.03,W,,5,W,4

    The three formats for latitude, longitude, and time zone are:
    degree ':' minute ':' second '.' decimal second     44:38:33.72
    degree ':' minute '.' decimal minute     44:38.562
    degree '.' decimal degree     44.6427

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    Contact Information

    UTMConvert was created by David W. Bray, Potsdam, NY
    Copyright © David W. Bray 2004-2005, All Rights Reserved.

    The Bray Mobile Applications Page can be found at: http://davidbray.org/mobile/


    UTMConvert is freeware -- no registration is required. We hope you enjoy using it.
    I would appreciate receiving e-mail about what computer(s) you are using UTMConvert on, and any other feedback and suggestions you would like to share with me.

    This archive may be freely redistributed, provided it is made available only in its complete, unmodified form with no additional files and for noncommercial purposes only.
    Any other use must have prior written authorization from David W. Bray.

    Unauthorized commercial use includes, but is not limited to:


    This program is provided without warranty and the user accepts full responsibility for any damages, direct, indirect, incidental, consequential, special or exemplary damages or lost funds or lost profit resulting from any use or misuse of this application.

    Foot Notes

    ¹ Ewe is developed by Michael L Brereton. We are indebted to him for his outstanding software product and making it freely available. Thank you Michael!

    The equations for UTMConvert came mainly from: http://www.gpsy.com/gpsinfo/geotoutm/gantz/LatLong-UTMconversion.cpp.
    A good introduction to UTM is: http://www.personal.psu.edu/users/p/u/pum123/GEOG%205121%20Project%201%20Sample%20Report.htm

    *Changes in Version 1.0

    UTMConvert Version 1.0 Bld:500 is the original release.

    To be sure that your version is up-to-date check the Bld: number in the current description of UTMConvert at: http://davidbray.org/mobile/

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