Pleiades (satellite)
The Pléiades constellation is composed of two very-high-resolution optical Earth-imaging satellites. Pléiades-HR 1A and Pléiades-HR 1B provide the coverage of Earth's surface with a repeat cycle of 26 days. Designed as a dual civil/military system, Pléiades will meet the space imagery requirements of European defence as well as civil and commercial needs.
History
The Pléiades system was designed under the French-Italian ORFEO program between 2001 and 2003.The Pléiades programme was launched in October 2003 with CNES as the overall system prime contractor and EADS Astrium as the prime contractor for the space segment.
Spot Image is the official and exclusive worldwide distributor of Pléiades products and services under a delegated public service agreement.
Launches
- Pléiades-HR 1A was launched via a Russian Soyuz STA rocket out of the Guiana Space Centre, Kourou, French Guiana, on December 17, 2011, 02:03 UTC.
- Pléiades-HR 1B was launched via a Russian Soyuz STA rocket out of the Guiana Space Centre, Kourou, French Guiana, on December 2, 2012, 02:02 UTC.
Technologies
Orbit
The two satellites operate in the same phased orbit and will be offset at 180° to offer a daily revisit capability over any point on the globe. The Pléiades also share the same orbital plane as the SPOT 6 and 7, forming a larger constellation with 4 satellites, 90° apart from one another.- Orbit: Sun-synchronous, phased, near-circular
- Mean altitude: 694 km.
Innovation
Agility for Responsive Tasking
This agility coupled with particularly dynamic image acquisition programming will make the Pléiades system very responsive to specific user requirements. Individual user requests will be answered in record time, thanks to multiple programming plans per day and a state-of-the-art image processing chain. Performance at a glance:- Image acquisition anywhere within an 800-km-wide ground strip with 70 cm of resolution
- Along-track stereo and tri-stereo image acquisition
- Single-pass collection of mosaics with a footprint up to a square degree
- Maximum theoretical acquisition capacity of 1,000,000 km2 per day and per satellite
- Optimized daily acquisition capacity reaching 300,000 km2 per day and per satellite.
Products
| Resolution | Panchromatic: 50 cm |
| Multispectral: 2 m | |
| Pansharpened: 50 cm, | |
| Bundle: 50 cm PAN & 2 m MS | |
| Footprint | 20 km swath |
| Single pass mosaics up to 100 km x 100 km |
Ground receiving stations
When satellite operations begin, four ground receiving stations will be deployed for the direct downlink and archiving of imagery data:- Two defence centres in France and Spain
- Two civil stations: one in Toulouse and a polar station in Kiruna, which will receive most of the data.
Uplink Stations
The Pléiades tasking plan will be refreshed and uploaded three times per day, allowing for last minute requests and the ability to utilize up-to-the-minute weather forecasts.- The Kerguelen Island station uploads the morning pass, over Europe, Africa and the Middle East.
- The Swedish station takes care of midday orbits, over North and South Americas.
- The French station transmits the last tasking plan of the day over Asia and Oceania.
Applications of VHR imagery
- Land planning: detection and identification of small features
- Agriculture: land management and crop yields, location of crop diseases, tree count
- Defense: imagery-derived intelligence and tactical planning in urban/densely populated areas
- Homeland Security: mitigation, assistance in crisis events and post-crisis assessment
- Hydrology: topography and drainage basin gradient studies
- Forestry: illicit deforestation and management of forestry yields; REDD data qualification
- Maritime and littoral surveillance: vessel reconnaissance and contamination, harbor mapping
- Civil Engineering/Asset Monitoring: planning of road, rail and oil pipeline corridors
- 3D: flight simulators, high precision mapping, photovoltaic fields implantation...