Every day countless satellites pass overhead gathering and sending all sorts of data as they go. Some are used for military "intelligence" gathering, some for scientific research some, telecommunications, or weather forecasting. Go outside shortly after sunset or just before sunrise on any clear evening and your sure soon to see what looks like a star slowly gliding across the sky. Some are dim some are bright, some "flare" suddenly. Not only can you gaze up and enjoy the unexpected beauty of a chance encounter, it is easy to find out which satellites will be passing over and when!
HEAVENS ABOVE is a great website. Simply input your location and elevation and it accurately tells you when to look and which satellite you will see. I guarantee that your first sighting of a particularly bright IRIDIUM FLARE (magnitude 0 or negative value) on a clear evening is an experience you will never forget!
Some satellites can be heard on relatively simple "hobbiest" equipment. The American military use the INMARSAT for some of their communications, these can be intercepted fairly easily with a quality radio scanner and antenna. For more information on this check out these sites.
To me a much more interesting aspect is WEATHER SATELLITE reception.
Using a radio-scanner, basic outdoor antenna and some shareware computer software, I can automatically capture and display actual coloured "cloud photographs" of Australia and New Zealand from the NOAA series of satellites as they pass over my home. There was also a Russian Meteosat, but, sadly it is no longer functioning. CLICK HERE to see some examples of satellite images that I have captured recently. Click Here for some older interesting ones
My system is a very basic one yet gives fine results with APT (Automatic Picture Transmission) mode from 3 satellites NOAA12 15 and 17. These transmit images on the frequencies of 137.500MHZ (NOAA12,15) or 137.620MHZ (NOAA17) FM (narrow). You need scanner/receiver capable of receiving FM (narrow) on this frequency with a 40-50KHZ IF bandwidth. I use an ICOM PCR100 which has a 50Khz setting. I use the freeware package TALK-PCR to control the radio as it can be set to change frequencies on a schedule.
The antenna can be a cheap commercial Discone (which I use) or home made Turnstile (basically two crossed dipoles cut to 137.500Mhz) mounted on your roof eaves or peak. When a satellite passes overhead a distinctive cheap-cheap signal can be heard from your radio. CLICK HERE to hear a NOAA signal.
I simply run a cable from the audio out (or headphones or external speakers) socket of my radio into the LINE IN socket of my PC. On my PC I have a couple of programs running minimised and waiting 24hours a day. When the software hears the signal it decodes the data and saves the image and sound file to my PC hard disk. I can then further enhance or reprocess the image and reuse, save delete the sound file.
I leave my system running 24hours a day, and generally get one or two very good daytime visible light "coloured photos", and a number of infrared back-and white night time images each day. Some very dramatic images can be also obtained just on dawn or dusk.
Here is the Satellite Software I recommend.
SATSCAPE. this tells you when the satellites are due to pass overhead (like heavens above website). This has spectacular graphics and will impress your friends (grin).
WX-Sat. This is an older 16bit program that doesn't seem to have been updated in may years, yet this easy to use program works very well indeed. processing the received audio into basic colour photos or infrared images. I would recommend you start with this one.
WXtoIMG. From New Zealand, WXtoIMG, is the prince of satellite image processing software. This can process the images in may ways, produce colour day and night, show different weather systems, and overlay maps of rivers and borders etc. There is a highly functional free version, a very powerful commercial version and a fully featured professional version that I think can actually make it rain (just kidding).
Other useful software, which may work well or not (I dont use them, but others say they are good) are:
still to come
If you know of any links of interest or software worth listing, or just want to say "G'day", EMAIL me vk2jem@qsl.net
73 De Jem
3 May 04