need help

Discussion in 'Wireless & RF Design' started by onair, Mar 22, 2006.

  1. onair

    Thread Starter New Member

    Mar 22, 2006
    I'm a student of kad poly in nigeria, and wanted to undertake a final year project on digital satellite. don't know if i can get any technical overview.
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    Do you wish to design and build equipment to communicate with satellites, or do you wish to design and build the satellite itself?
  3. Papabravo


    Feb 24, 2006
    There are at least two types of satellites whic are used for communications. The first type is in a stationary, geosyncronous orbit about 22,500 miles from the surface of the earth. Geosyncronous means that the satellites move at the same speed as the earth rotates, and so remain stationary above a fixd spot on the earth. These satellites are owned and operated by commercial enterprises. It is my opinion that they would take a dim view of your attempts to use their equipment for you own purposes. I also think it would be difficult to find enough technical information to do this succcessfully.

    The second type of satellite is in low earth orbit, maybe 120 to 400 miles above the surface of the earth. These satellites provide a small window of about 15 minutes while they transit over your position in which they can be used to communicate. The transmitter and receiver are only the beginning of your problems. Because of the Doppler shift you need to constantly change both the uplink and downlink frequencies of your equipment to maintain communications as you track the satellite and continuously reposition your antenna so that you can maintain adequate signal levels for reliable data transfer.

    I don't know about the rules in Nigeria, but this kind of work is much easier if you have an amateur radio license. Doing this kind of work in the United States, without a license of some kind, could get you in some real legal trouble. Interfering with someone else's signals will definitely get you in trouble.