The Black Stork wears a "backpack" consisting of one smaller terrestrial and one bigger satellite transmitter. The terrestrial one is always active but reaches for only a few miles. The satellite transmitter must be intricately timed due to the limited battery capacity and that is why it for instance transmits 6 hours long and the next 12 hours its inactive. Two satellites of National Oceanic and Atmospheric Administration (NOAA) receive its signals in the open space.
|Čáp s "batůžkem"|| |
One of the NOAA satellites before blasting off. It has now been circling at orbit, 900 km from the Earth. As soon as it receives the signals of the satellite that the stork transmits from its "backpack," it preprocesses and passes them to terrestrial center in Alaska or France.
The terrestrial center arranges handing the information over from the satellite to the Argos system central office in Toulouse (France). After complicated calculating, the coordinates of the watched stork are at hand no sooner than a half an hour after the delivery. Those coordinates are together with other data transmitted into Czech Radio's data network in Prague and there they also appear on the computer monitor.
|Družice NOAA|| |
An expedition seeking the stork must ask for the coordinates. Satellite phone serves well within places out of civilization. At the photo taken in East-African bush land, its flat antenna points at Inmarsat satellite over the Indic ocean. This phone enables us to enter the radio transmission from any place on the planet Earth. Only after the expedition reaches the point where the watched stork was recorded by Argos system, the terrestrial transmitter has its word. It may be accurately aimed by means of a directional antenna - and after that you are able to watch the stork directly or estimate its behavior (feeding, taking rest on the tree, circling around etc.) according to the signal changes.
|Zaměřování anténou|| |