Using UTMConvert
When you first open UTMConvert the main screen has no data defined.Referring to the UTMConvert display at the right, you see:
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.
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
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
The Menu button row has 3 menus:
If you again tap and hold (or right mouse click) the Latitude or Longitude value a
Cut/Copy/Paste menu will appear.
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: This North America 1927 datum is to be use with continental United States maps. The flattening f is defined as: (EquatorialRadius-PolarRadius)/EquatorialRadius.
So the PolarRadius is EquatorialRadius * (1-f). 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.
------------------- Reference Ellipsoids and Parameter Differences Where DA(M) is the EquatorialRadius correction, and Df x 10^4 is the flattening correction.
Working out North America 1927 (Alaska) Corrected EquatorialRadius is 6378206.4 - 69.4 = 6378137
Corrected InverseFlattening computed as follows: Result: 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!
Having a file of locations is much easier than entering a location manually when you want
different information -- especially for travelers. 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:
Example: The three formats for latitude, longitude, and time zone are:
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
North America 1927 (U.S),6378137,298.257223532662
The earth's equatorial radius = 6378137.
The inverse of the flattening = 298.257223532662
Using the above datum:
PolarRadius = EquatorialRadius * (1-1/298.252235) =
PolarRadius = 6378137 * (1-0.003352810665) =
PolarRadius = 6378137 * 0.996647133 =
PolarRadius = 6356751.957
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.
NORTH AMERICAN 1927
Alaska (Excluding Aleutian Islands)
Name DA(M) Df x 10^4
Clarke 1866 -69.4 -0.37264639
-------------------
Clarke 1866 is:
Clarke 1866,6378206.4,294.9786982
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.
About Location Data
The Location Data
allows you to select a location on the Earth for UTMConvert.
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.
Potsdam NY,44:38.562,N,75.03,W,,5,W,4
| degree ':' minute ':' second '.' decimal second | 44:38:33.72 |
| degree ':' minute '.' decimal minute | 44:38.562 |
| degree '.' decimal degree | 44.6427 |
The Bray Mobile Applications Page can be found at: http://davidbray.org/mobile/
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:
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
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/