Satellite tracking or Bird watching as it has become widely known

Ever wondered why, with so much space junk, satellites and who knows what floating around up in space, none of it crashes into each other? That is why the joint space agencies take so much time in planning an orbit or geostationary satellite (one that stays in a fixed position relative to the earth) way before it even reaches the launch pad. It is a mammoth task to keep track of all the satellites alone without all the other stuff that is up there. Whilst there are a number of earth tracking stations with huge great big radar tracking systems (not to be confused with places such as Jodrell Bank which is a radio telescope). It is also possible, with the aid of a PC, Apple Macintosh or Atari ST to name a few computers, to track these satellites yourself at home. Here are just a couple of methods whereby you can start tracking those elusive satellites. Even if you do not have a suitable PC you can also use the internet if you use either Netscape or Microsoft Explorer. If it’s for amateur radio, weather satellites or even GPS, there is some kind of software for you to use.

WinOrb PC satellite tracking

WinOrbit is a program for computing artificial Earth-satellite position and visibility, with the Amateur Radio Satellite operator in mind, with 4 basic functions:

1. Graphical and pictorial display of satellite positions in real-time, simulation, and manual modes.
2. Tabular display of satellite information in the same modes.
3. Output of current tracking information (az, el, doppler, etc.) to a client program for control of tracking hardware such as antennas, radios, or telescopes.
4. Generation of tables (ephemerides) of past or future satellite information for planning or analysis of satellite orbits.

Incidentally, support is also provided for maintaining a database of satellite orbital information and a database of observer locations. Once installed, there are a number of items that need to be set up otherwise you will not be getting the most out of the program. Firstly set up the users QTH as this will determine when the satellites will come into range at your location. Check that the time zone is correct, bearing in mind that the software works at GMT time, so you will need to adjust this if you are running the software from a different country. Or if you are in a country that has a summertime adjustment as we do with British Summer Time, which will be changing back to GMT after October.

The principal feature of WinOrbit is a series of Map Windows, which display the current position of satellites and observers on a simple world map, together with information such as bearing (azimuth), distance, and elevation above the observer's horizon. The maps can be updated in real time, or in simulated time, or manually set to show the situation at any time past or future.

A Table Window displays much more-detailed information about one or more satellites in a tabular form. The tabulated items can be selected and rearranged to fit the screen. This information likewise can be updated in real-time, manual, or simulation modes.

Additional noteworthy features include: Simultaneous tracking of up to 20 satellites. Choice of 4 tracking algorithms. A view from space map presentation showing what a particular satellite sees. Computation of Doppler shift and path loss for communications satellites. Utility functions for modifying and comparing published element sets, including post-launch updating of pre-launch elements, and saving composite data files compiled from various sources. Built-in tracking of Sun and Moon, and support for tracking astronomical objects (given Right Ascension and Declination) or geostationary satellites. DDE server interface to tracking-antenna or doppler-shift correction hardware controllers, compatible with the Full Doppler Tuning standard. WinOrbit can run in a "server only" or "mapless" mode to conserve memory when needed.

Tracking data (Keplerian element sets) read from standard, off-the-air bulletins in three different formats (unlimited number of satellites). No pre-processing is needed, just select a bulletin file. Auto Update is now possible. Observer (QTH) data (latitude, longitude) may be imported from a simple text database (unlimited number of observers) Printing of tables of tracking data (Ephemerides) in several user-configurable formats. Table printing does not interrupt tracking. Table output may be directed to a disk file, for later analysis in a spreadsheet, for example. On-line help including direct access to text information about each satellite from the map windows, and "context-sensitive" help accessible directly from various windows. Standard Windows interface for all functions - no commands to memorise. Both mouse and keyboard can be used for most functions.

JTrack Online Internet satellite tracking

The satellites are tracked using a special JAVA Applet named J-Track. An Applet is a small program that runs within the internet browser software. J-Track is still under development and more improvements are in the plans. The current version, 2.0b1, has undergone some internal reworks to avoid bugs in the following browsers:

Each of the above versions has problems handling time. Either they give the wrong GMT time in milliseconds, convert milliseconds to a GMT string wrong, or they just don't work at all. This new version works around these bugs by -

1. Downloading the GMT time from our server and comparing it to your local system clock.
2. Using our own date and time functions rather than those that come with JAVA (they only seem to work on some browsers) - thanks Netscape.
3. Fragmenting perfectly good equations into multiple short equations for Netscape 3.0.1 on the PC
4. Not converting double to long integers for Internet Explorer 3.01 on the Mac.

JAVA truly is the great equalising software. It has reduced all computers to mediocrity and buggyness.

I found the program very versatile especially if you have a fast enough PC, they recommend the equivalent to a 166Mhz PC or better you can they run the 3D version of the JAVA software. This allows you to have a three dimensional view of the earth from somewhere out in space, with the relevant selected satellites in view at their allotted geometric position.

You can also rotate the earth and its constellation of satellites by clicking on the map with the right hand mouse button and dragging it to the desired position. Therefore allowing you rotate the earth so that any view of the earth may be obtained.

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