They usually seem to be pointed up into the sky (towards some
satellite); is there information available about these satellites,
their downlink frequencies, format of the data, etc.?


All the satellite weather/water data ground stations I can think of use
an uplink of around 401 MHz. (There is NO downlink to these ground
stations; their TX is controlled by clock controlled TX time slot.)

The government geostationary satellites, like GOES 7, are downlinking
the data to a Central site in Virginia on around 4 GHZ, I think, and
higher. From there, the raw data is processed and sent back out to
several differnet locations, including more satellites for relay.




Ed