This paper describes the technical details behind the Tracking for the Beyond Blue charity event. You can see the live images here
TC Communications, have provided a combined GPS receiver and Inmarsat D+ Satellite terminal for the tractors as the journey through the arid Australian interior. Unlike the dishes commonly used to receive Satellite TV, the Inmarsat D+ terminal is about the size of a discus used in sporting events, or about 20cm in diameter and 6cm high as a single unit combining antennas and electronics.
This small package of electronics is programmed to uplink position reports periodically to an Inmarsat Satellite in Geosynchronous orbit about 35,000 KM above the equator. Once received by the satellite, it is then sent to one of the international earth stations operated by Inmarsat before being sent to the TC Communications Offices in Sydney.
Radioactive Networks TeamTrack Interface
Once the position reports are received in the TC Communications offices, the reports are then queued to be sent to the TeamTrack server software supplied by Radioactive Networks. The first step involves a ‘listener’ program operating in the TC Communications offices which accept the messages and then send them to a server operated by NetIntellect in Albury using a WebServices interface to the TeamTrack server and database.
The WebServices then ensures that the position reports are authenticated, and then adds the positions to its SQLserver Database. This database is running under Windows Server 2003 and IIS6.
GPS-OZ has provided maps for the Australian OziExplorer software. Radioactive Networks TeamTrack Pro software is used to connect to the TeamTrack WebServices server in Albury, and upload the position reports into OziExplorer as well as provide history and reporting functions.
In order to show what this would look like on the web, Radioactive Networks have this software running on one of their machines in their Sydney offices, and are using the SnagIt software to take a Print Screen of the software every few minutes. The SnagIt software then uploads the images to the Radioactive Networks Web Server, outsources with PowWeb.Com, providing up to 300 GBytes of bandwidth a month.
These static images are then linked to by the main Web Site being hosted by NetInetllect
One of the components of the Radioactive Networks TeamTrack suite is an interface to Google Earth. This interface operates in two parts to reduce CPU load under heavy usage. The exact details are commercially sensitive, but once again Web Services pay an important part. The interface ultimately involves a specially formatted dynamic web page containing the current location information and historical journey data.
This information is then decoded by Google Earth and displayed on the map. Google has been set up to periodically request updated positions from the server and display them on the screen. Once again, just like with OziExplorer, screen dumps are taken and uploaded to the Web Site.