GreatCircle Application for Ewe
Version 1.0*

Description

Main GreatCircle Display GreatCircle is an application for Ewe enabled computers to compute the great circle distance between two locations on Earth. It also displays the great circle bearing angle from one location to the other. GreatCircle will accurately compute short distances and thus is useful for geocaching.

To use this version of GreatCircle 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.

GreatCircle displays the following data:

We hope you find GreatCircle a useful adjunct to your Mobile applications.

Installation

Since you are reading this documentation, you have found that there are two .zip archives in greatcircle10.zip. The greatcircle10Install.zip archive contains the files to be installed on your computer. The greatcircle10Doc.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 GreatCircle.ewe. The files in the greatcircle10Install.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.

So once you find the proper directory copy all of the files in greatcircle10Install.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), GreatCircle always uses the '.' (period) as the decimal point, the ':' (colon) as the hour/minute/second separator, and the ',' (comma) as the data separator.

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

Using the Application

GreatCircle Location Form When you first open GreatCircle the main screen has no data locations defined.
Referring to the GreatCircle display at the top of this page, you see a row of Menu Buttons, a top row of two buttons: From and To, a data area, and a bottom row of two buttons: Main and Locations.

The Menu Buttons are discussed last below.

Controls -- Top Buttons

The From and To buttons popup a Location Form for entering location data manually, as show to the right. Enter the desired data for the Name (optional), Latitude and Longitude and set their direction from Greenwich or the Equator using the pull-down selectors.

Once both the From and To locations have been define the Distance and Bearing will be computed.

Controls -- Bottom Buttons

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

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

Menu Instructions

The Menu button row has 4 menus:

More Details

Supplied Location Data

Greatcircle10Install.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 come 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 a GreatCircle.

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 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 GreatCircle)
    7. Time Zone -- Three possible formats (not used in GreatCircle)
    8. Time Zone Hemisphere -- E (Eastern) or W (Western) (not used in GreatCircle)
    9. Daylight Time Code -- Digit (not used in GreatCircle)

    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 Info

    GreatCircle was created by David W. Bray, Potsdam, NY;
    Copyright © David W. Bray 2004, All Rights Reserved.

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

    Registering

    GreatCircle 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 GreatCircle 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:

    Disclaimer

    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 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!

    *Changes in Version 1.0

    GreatCircle Version 1.0 Bld:445 differs from Version 1.0 Bld:419 in:
    1. Changed the '.' (period) to always be the decimal point. (V1.0 Bld:438)
    2. Fixed Location File open error. (V1.0 Bld:445)
    Bld:445 is the current release.

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

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