Pléiades

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Pléiades is a pair of earth observation satellites belonging to the French-Italian satellite program Orfeo . They are the optical component of the Orfeo system, which is intended for both civil and military use, and are smaller, cheaper and more mobile than their predecessors from the SPOT satellite series.

Pléiades 1A and Pléiades 1B are operated as a constellation in the same orbit, 180 ° apart. The two identical satellites deliver very high-resolution optical data products in a short period of time and enable a daily new acquisition of any point on earth.

Missions

Studies for the satellites began in September 2000, and actual development began in October 2003.

Pléiades 1A was launched into sun-synchronous earth orbit by the Center Spatial Guyanais on December 17, 2011 at 2:03 am (UTC) by a Soyuz ST rocket along with four Elisa satellites for the French military and the Chilean satellite SSOT . The Elisa satellites each have a mass of 120 kg and should record ground-based radar sources and their characteristics for military reconnaissance. EADS Astrium was the prime contractor for all satellites .

Pléiades 1B was also launched from the Center Spatial Guyanais on December 2, 2012 at 2:02 a.m. (UTC) with a Soyuz-ST into the same orbit but offset by 180 °.

Structure and payload

The three-axis stabilized satellite is equipped with a camera with a primary mirror diameter of 65 cm, which achieves a resolution of 50 cm for color or black-and-white images and a resolution of 2 m for multispectral photos. The recordings are made by five line sensors with a width of 1500 pixels for multispectral and five line sensors with a width of 6000 pixels for the panchromatic area. The satellites and their orbits were designed in such a way that together they can record every area of ​​the earth at least once a day. It was built by Thales Alenia Space and has a planned lifespan of five years.

Technical specifications

Orbit

The two satellites are operated as a constellation and operate in the same orbit at an angular distance of 180 °, in order to offer a daily detection possibility for every point on earth.

  • Orbit: synchronized with the sun, offset by 180 °
  • Average altitude: 700 km

innovation

Pléiades 1A and Pléiades 1B are equipped with the latest generation of innovative space technology such as fiber optic gyroscopes (IFOG for short) and control moment gyroscopes (CMG, inertia wheel) and therefore offer excellent turning, tilting and swiveling agility.

Agility for responsive tasking

Thanks to this agility in connection with the particularly dynamic image acquisition programming, the Pléiades system can react quickly to special user requirements. Individual user inquiries are processed in record time. The recording performance is due to the underlying agility of the satellite platform in combination with the extensive stripe width (20 km) of the optical instrument. Performance data at a glance:

  • Image acquisition worldwide in an 800 km wide strip of soil with sub-meter resolution
  • Along-track stereo and tri-stereo image capture
  • Single-pass collection of mosaics (strip mapping) in a single overflight with an area of ​​100 km × 100 km
  • Daily recording capacity of over 1,000,000 km²
Data
resolution
  • 70 cm panchromatic
  • 270 cm multispectral
Spectral ranges
  • Blue: 430-550 nm
  • Green: 490-610 nm
  • Red: 600-720 nm
  • Near infrared: 750-950 nm
  • panchromatic: 480-830 nm
Location accuracy
  • 1 m with control points on the surface of the earth
  • 4.5 m (CE90)
Daily intake
  • 1,000,000 km²
  • Mosaic of a special area: 100 × 100 km
  • Stereo images of a specific area: 20 × 280 km
  • High-resolution images of a specific area: 30 in an area of ​​100 × 200 km
Swath width 20 km

Applications of the very high-resolution recordings

The Pléiades system is designed for very high resolution (VHR) remote sensing applications. This includes:

  • Spatial planning: Detection and identification of objects with a size of less than 1 km² (e.g. vehicles, infrastructure, roads, bushes)
  • Agriculture: Management of land and crop yields, tracking of plant diseases
  • Urban Planning and Demography: Locations of Detached Houses
  • Defense: visual information and tactical planning
  • Civil protection: damage reduction, support in crisis situations and evaluations after a crisis (especially in the event of earthquakes)
  • Hydrology: Investigation of the topography and the slope in precipitation areas
  • Forestry: illegal logging and management of forest yields
  • Maritime and coastal surveillance: ship reconnaissance and pollution
  • Construction: planning of road, rail and oil pipeline corridors

Web links

  • CNES: Pleiades (English / French)
  • Astrium Geo: Pleiades
  • PLEIADES-HR IMAGE SYSTEM PRODUCTS AND QUALITY: [1] (PDF; 218 kB)

Individual evidence

  1. ↑ Russian Soyuz rocket launches six satellites into space
  2. ↑ a b raumfahrer.net: Soyuz brings satellite sextet into space
  3. ↑ RIA Novosti: Soyuz-ST launcher launches European satellite Pleiades 1B into orbit
  4. ↑ CNES: PLEIADES HIGH RESOLUTION SATELLITE
  5. ^ GEO Information Services: Pleiades User Guide. astrium-geo, October 2012, accessed May 30, 2016 .