In order to accurately measure the position of the satellite, CryoSat carries some additional specific equipment:

• The Doppler Orbit and Radio-positioning Integration by Satellite (DORIS) radio receiver detects and measures the Doppler shift of signals broadcast from a network of over 50 radio beacons spread around the world.
• A small laser retro-reflector reflects light back in exactly the direction it came from. A global network of laser tracking stations fire short laser pulses at CryoSat and record the time-interval before the pulse is reflected back. This provides independent reference measurements of CryoSat's position.
• The International Laser Ranging Service (ILRS) provides tracking from its global network of laser ranging stations to support the project.