PO-28 (POSAT-1) Java station control program

The email below is from John Melton G0ORX/N6LYT. He has a new version of his Java station control under development which will be released if PO-28 (POSAT-1) is put into digital operation.

He gives a useful URL for some of the images that POSAT took when it was operating on commercial frequencies. They give some idea of the satellites capability.

PO-28 Uplink Frequencies: 145.925 MHz and 145.975 MHz
Downlinks: 435.250 MHz or 435.275 MHz FM

Further information on PO-28 can be found at:
http://www.amsat.org/amsat/sats/n7hpr/po28.html
and http://www.ee.surrey.ac.uk/SSC/CSER/UOSAT/missions/posat1.html

It is likely to be mid-August before PO-28 is available to Amateurs.

73 Trevor M5AKA

Java station control program

Hi,

I am the developer of JStation. The version that is on
http://www.qsl.net/n6lyt is now really really old.

I was working on a newer version that used the Java Comm API for the serial port interfaces. There are a lot of changes in this version but I lost interest due to the lack of store and forward digital satellites and in particular images taken by the satllites.

I had implemented the alogorithms required to decode the PoSAT images. They were using a method called "Adaptive, Moment Preserving Block Truncation Code" see:
http://www.ee.surrey.ac.uk/SSC/CSER/UOSAT/IJSSE/issue1/brewer/Brewer.html
which required a complete thumbnail image along with the encoded full image to be able to decode them.

I also have a version under construction that runs the interface to the rotors and radios as a background task (daemon) and presents the user interface via a web browser using Java Servlets and Java Server Pages. As the machine that this runs on is on the internet I can access the satellite data from anywhere that has a browser and internet access!

If the store and forward part of PoSAT is made available I will put some effort into getting this all running again and put together in a releasable form.

I was monitoring PoSAT for a long time on its commercial frequency and had noticed that it was not being used apart from downloads of log files and the occasional WOD file.

The images from this satellite were really good, see:
http://www.dop.ineti.pt/posat/www/index.htm, I hope that we will be able to use that part of the satellite.

Regards,

John Melton g0orx/n6lyt

When PO-28 is switched to Amateur operation you will be able to use the Online Satellite Predictor to find out when it's in range: http://www.amsat.org/amsat-new/tools/predict/
Select Show Predictions for PO-28 and enter your approximate Lat and Long co-ordinates or IARU QTH Locator.

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