Minimize Altimetry Instruments Payload

The main characteristics of the SRAL (SENTINEL-3 Ku/C Radar Altimeter) are:

  • possible radar measurement modes: LRM and SAR (operating 100% in SAR in orbit)
  • tracking modes: closed and open-loop
  • pulse repetition frequency: 1.9 KHz (LRM), 17.8 KHz (SAR)
  • total range error: 3 cm
  • launch mass: 60 kg.

The main characteristics of the MWR (MicroWave Radiometer) are:

  • dual frequency, 23.8 / 36.5 GHz
  • radiometric accuracy, 3 K absolute (0.6 K relative)
  • launch mass: 26 kg.

Precise Orbit Determination (POD) including:

  • GNSS receiver (Global Navigation Sat. System)
  • DORIS Doppler Orbitography and Radiopositioning Integrated by Satellite
  • LRR Laser Retro reflector

Figure 1: SRAL Instrument (Credit: ESA)

Figure 2: MWR Instrument (Credit: ESA)


Figure 3: DORIS Instrument (Credit: ESA)


Figure 4: GNSS Instrument (Credit: ESA)


Figure 5: LRR Instrument (Credit: ESA)