Passive Correlation Ranging (PaCoRa)

Satellite Tracking

Passive Correlation Ranging (PaCoRa) is an efficient, accurate and cost-effective solution for determining a satellite’s position without transmitting a signal uplink. It can be used on any operational geostationary satellite, irrespective of the satellite operator or region.

PaCoRa monitors a satellite‘s downlink signal through multiple ground stations within the satellite‘s footprint. For each of these stations, PaCoRa determines the signal’s Time Difference of Arrival (TDOA) which it then uses to determine the satellite’s position and predict its orbit based on the geographical coordinates of these Stations.

Previous state-of-the-art tracking systems were based on tone ranging, which required active uplinks and large antennas. The prevalent solutions, such as dual tone ranging or trilateration, require two or three active uplinks. In comparison, PaCoRa only uses the downlink signal for its calculations.

Key benefits:

A passive system

  • Receive only, so only small antennas and standard Radio Frequency (RF) front-end hardware are required
  • Any type of signal, whether it be payload, telemetry or transponder noise
  • Any frequency bandwidth, such as L, S, C, X, Ku or Ka, and any modulation process
  • No uplink for ranging and so no impact on the satellite
  • Ability to range all operational geostationary satellites
  • Orbit determination of own satellites and third party satellites

High availability

  • The ground station redundancy design is 4:1, while the hot redundancy connection ensures no outage time after failure 

Schedulable self-calibrated system

  • Continuous or scheduled sets of tracking data at a rate of 1/s
  • Multi-satellite ranging is possible with a single system, along with multiple orbital positions and  bandwidths

Operational ease

  • Fully automated maintenance and control
  • Suitable for any type of footprint (global, continental, spot beams)

Very accurate

  • Data is suitable for high-demand applications while a larger number of terminals gives a greater degree of accuracy