Ground Station

The main ground station for receiving Pratham signals is situated on the roof-top of Aerospace Department of IIT Bombay. It has the following major functions:

  • Satellite tracking and receiving segment
  • Uplink transmission segment
  • Payload data logging

Main Ground Station of Pratham on the roof-top of Aerospace Department, IIT Bombay

Ground Station Block Diagram

At the GS we have some self-fabricated and some off-the shelf components.

  • Antennas: Two pairs of crossed yagi antennas, one pair for each frequency band i.e. central frequency 145.98 MHz, 437.455 MHz
  • Transceiver base station: Kenwood TS2000 radio demodulates the FSK signal and stores the data in the mainframe.
  • A pair of AD8302 modules measures RF gain and phase value between the two inputs it takes Uses Log amplifiers to calculate the value of log (InpA/ InpB)
  • Low Noise Amplifiers: 4 low noise amps are being used on the distinct feeds from antennas
  • Rotor arrangement with an Interface circuit to integrate the device with software architecture. Rotor (Yeasu G-5500) is being used to orient the antenna structure to the required inclination with respect to reference level. The rotor interacts with the mainframe via Rotor Controller Interface (RCI-USB by EA4TX)

Ground Station Mainframe Setup