> Platforms
> Satellites
> Antennas
> Processing centers
> Data dissemination
> Tracking
     > Doppler location
     > GPS positioning
> Monitoring

Platforms

An Argos platform is a terminal equipped with a transmitter dedicated to Argos system. Each platform, sometimes called a Platform Transmitter Terminal or PTT, has an individual identification number. The main signal characteristics are:

• Transmit frequency: 401.650 MHz +- 30 kHz. The frequency allocated to each transmitter within this range must remain stable, as the Argos location calculation is based on measurements of the Doppler effect on the signal
• Repetition period, assigned according to application; for example 90 seconds, once every other day…
• The platform message includes:
  • A preliminary synchronization sequence,
  • Statement of message length
  • The transmitter ID number
  • The sensor data or other message data (32 to 256 bits)

Each message lasts 360 to 920 milliseconds, according to the length of the message.