Components and Specifications

RADARSAT Constellation mission consists of the following segments:

RADARSAT Constellation mission consists of the following segments

Space Segment

The Radarsat Constellation Mission Space Segment will consist of a constellation of 3 satellites in a low-earth orbit. Each of the Spacecraft in the constellation will consist of a Bus and a SAR payload. There is also a secondary payload allocation for a potential Automated Identification System for ships (AIS) which is not planned as part of the baseline mission and is being considered by DND. The radar payload will perform all imaging operations, store, encrypt and transmit the radar data. The AIS payload could receive ship's messages in a wide swath larger than the accessible swath of the SAR. The Bus module will provide attitude and orbit control, power generation and storage, payload commands, telemetry, thermal control and the primary support structure.

Space Segment

Main Space Segment Parameters

# of satellites 3 equally-spaced in a dawn-dusk plane
Bus Canadian Smallsat Bus
Launcher DNEPR specifications (for design)
Total Mass < 1300 kg
Antenna 9,45m2
Power < 1600 W (peak); < 220 W (average)
Orbit 600 km, 100 m radius orbital tube
Polarisation Dual cross selectable pole on all low and medium resolution modes; "experimental" quad pol
Imaging Time 12 minutes/orbit (peak 20 minutes every three orbits) 10 minutes continuous imaging
Lifetime 7 years (each satellite)

Ground Segment and Operations Concept

The baseline ground segment is based on upgrades to the existing RADARSAT-2 ground segment, using the Gatineau and Prince Albert stations for data reception, the St-Hubert and Saskatoon stations for TT&C and the Svalbard station as a backup for TT&C and data reception. It will be harmonized for data reception at the Polar Epsilon coastal stations in order to support near-real time maritime surveillance. It will also include a fast tasking capability allowing access to the satellites on every orbit, likely achieved through international partnerships.

Ground Segment

The RADARSAT Constellation will require ground stations with vast coverage over Canadian maritime zones of interest in order to provide data within 10 minutes of acquisition. The ground segment will be based on upgrades to the existing RADARSAT-1 and 2 ground segment, using the Gatineau and Prince Albert stations for reception and the St-Hubert and Saskatoon stations for TT&C. Upgrades will allow basic constellation operations. It will be extended to include upgrades to coastal stations and potential international partnerships in order to support near-real time maritime surveillance. It will also include a fast tasking capability allowing access to the satellites on every orbit, likely achieved through international partnership.

The following figure demonstrates baseline RADARSAT Constellation Mission reception stations

RADARSAT Constellation Mission reception stations



The following figure shows proposed RADARSAT Constellation Mission Telemetry, Tracking and Control System

RADARSAT Constellation Mission Telemetry, Tracking and Control System

The maritime surveillance requirements are among the most demanding from a mission and system requirement point of view. DND has a requirement to cover three zones extending up to 1000 nautical miles from the coast, which are shown below. Transport Canada has requirements to detect ships four days before they enter Canadian waters, which involves voluntary disclosure out to 2000 nautical miles, and imaging out to 1200 nautical miles.

Maritime Surveillance Areas for Ship Detection

Maritime Surveillance Areas for Ship Detection

An important aspect of the system operation is the availability of an Automated Identification System (AIS) payload for ship identification. Using AIS, ships exchange information on their identity, position, course etc. The RADARSAT Constellation spacecraft will carry an AIS receiver to gather information on ships over the zone covered by the SAR payload. The AIS will report most of the ships over the zones of interest.

Launch Segment

Launch Segment will consist of the launcher and launch service provider. The mission will use a single spacecraft / single launcher configuration.

The mission planning and spacecraft control functions will be located at St-Hubert.

System Characteristics

Radar  
Bande C 5.405 GHz
Imaging Time/satellite 12 min average/orbit
Orbite  
Altitude (Nominal) 592.7 km
Inclination 97.74 degrees
Period 96.4 minutes
Ascending mode 18 hours (+ -15 min)
Sun-Synchronous 14 11/12 orbits per day
Repeat cycle 12 days