Components and specifications
Space segment: the spacecraft
Text version - of image RCM space segment
Credit: Canadian Space Agency (CSA)
The RADARSAT Constellation Mission (RCM) is a trio of identical satellites flying in a low Earth orbit (altitude from 586 km to 615 km). Each of the spacecraft consists of a bus and a Synthetic Aperture Radar (SAR) payload. There is also a secondary payload, an Automatic Identification System (AIS) for ships, that is used independently or in conjunction with the SAR.
- The bus module provides attitude and orbit control, power generation and storage, payload commands, telemetry, thermal control and the primary support structure.
- The SAR payload performs all imaging operations, store, encrypt and transmit the radar data.
- The AIS payload receives ships' messages in a wider swath than the one covered by the SAR.
– The Making of a Satellite: The RADARSAT Constellation. (Credits: CSA, MacDonald, Dettwiler and Associates Ltd.)
Transcript| Number of satellites | Three, equally spaced in a dawn-dusk plane |
|---|---|
| Bus | Canadian SmallSat bus |
| Total mass | 1400 kg |
| Antenna | 9.45 m² |
| Power | < 1600 W (peak); < 220 W (average) |
| Orbit | 586–615 km Sun-synchronous maintained within a 100 m radius orbital tube |
| Polarization | Single pol / dual co-cross selectable pol & compact polarimetry available on all modes; dual HH-VV available for specific modes; one quad-polarization mode |
| Imaging time (out-of-eclipse) | 15 minutes/orbit average (peak 25 minutes/orbit every 3 orbits) 12.5 minutes continuous imaging |
| Lifetime | 7 years (each satellite) |
Ground segment
The RCM requires ground stations with vast coverage over Canadian maritime zones of interest in order to provide data within 10 to 30 minutes of acquisition.
The ground segment is used to:
- Command and monitor the satellites for navigation and imaging;
- Receive satellite telemetry;
- Receive data from the satellites' payloads; and
- Manage the data for users.
The mission planning and operations of RCM is conducted by the CSA in collaboration with industrial partners. To fulfill this function, a state-of-the-art Primary Control Facility at CSA headquarters in Longueuil, Quebec, and a Back-up Control Facility in Ottawa, have been built.
In addition, the Department of National Defense, through the Polar Epsilon 2 Project, is also organized to order, process and receive data.
The Canada Centre for Mapping and Earth Observation, a division of Natural Resources Canada, hosts the SAR data archives through the Earth Observation Data Management System.
Shared Services Canada is responsible for communications infrastructure between the various subsystems of the ground segment.
Finally, a network of ground stations helps command and track the spacecraft and receive data, including:
- Prince-Albert, Saskatchewan; Inuvik, Northwest Territories; and Gatineau, Quebec for S-Band command and telemetry reception as well as X-band data reception;
- X-band receiving stations in Aldergrove, British Columbia and Masstown, Nova Scotia;
- Northern Ground Terminal (Kiruna station from Swedish Space Corporation) used mainly for the Launch and Early Orbit phase and fast-tasking of the constellation.