Home reports air SARah satellite reconnaissance systems completely in space

SARah satellite reconnaissance systems completely in space

Gerhard Heiming

December 26, 2023

On December 24th, the two reflector satellites for the Bundeswehr's SARah (Synthetic Aperture Radar altitude high) satellite reconnaissance system were launched into orbit at an altitude of 500 km from the Vandenberg Space Force Base in California using a Falcon 9 rocket from the American company SpaceX as the main contractor, the road transport company OHB, announced.

The first satellite with the phased array radar has been in orbit at an altitude of 750 km since June 2022 (ESuTreported) and in operational partial operation (ESuT.) since October 2023reported).

According to OHB, after a flight time of 25 minutes, the two satellites were released into space as planned. Shortly afterwards, the first signals from the two satellites could be received. This marked the beginning of the so-called Launch and Early Orbit Phase (LEOP), during which the satellites are started up system by system and checked for functionality. In addition, the satellites are steered into their final orbits during this phase.

“With today’s launch we are not only completing the SARah constellation. This milestone is a further step towards offering the troops an improved, global, time-of-day and weather-independent reconnaissance capability in the future,” said the project manager from the Koblenz Federal Office for Equipment, Information Technology and Use of the Bundeswehr. The next goal is full operational operation next year.

SARah is intended to replace the successful SAR Lupe satellite constellation, which has exceeded its planned lifespan of ten years by 50 percent since 2008 and is still functioning. SARah is intended to bring a leap in intelligence performance. On the one hand, the resolution should increase from under one meter to the centimeter range. More storage space allows for larger images in a faster image sequence. On the other hand, signal transmission is accelerated by the second ground station (in Kiruna). Waiting times due to lack of antenna coverage are reduced.

According to information from OHB, a total of three radar satellites were developed and built for the mission in cooperation with Airbus Defense and Space as a subcontractor: a phased array satellite (contributed by Airbus Defense and Space) and two identical reflector satellites (by OHB). it is a further development of the proven technology from SAR-Lupe. By combining the two types of satellites, the advantages of the individual technologies can be used for the entire system in order to provide the Bundeswehr with improved global reconnaissance capability regardless of the time of day and the weather.

The actively emitted electromagnetic pulses of the radar satellites are only slightly influenced by cloudiness in the atmosphere and provide reliable images even in the dark and through dense cloud cover, writes OHB. In addition, radar pulses are reflected particularly well by water and metal, making infrastructure, vehicles and weapon systems particularly easy to detect. In some cases, according to OHB, recordings can even be made through trees, camouflage nets and the top layer of soil. Another advantage of radar satellites is that they can also precisely record the speed of movement of objects and height differences in the terrain.

The data generated by the radar systems on the satellites are transmitted as raw data to the ground segment, where they are further processed into images that are analyzed and interpreted by trained personnel.

According to OHB, the ground segment of the SARah system includes elements for commissioning the system, satellite control, image processing and archiving, two ground stations (in Gelsdorf and Kiruna, Sweden) as well as various interfaces to the customer and other systems.

As the main contractor for the SARah system, OHB is responsible for the most important functions of the ground segment, all interfaces to the customer and for the ground station in Gelsdorf. OHB develops and builds the elements required for reflector technology; the subcontractor supplies the corresponding elements for the phased array technology.

The operation of the SARah satellites under the responsibility of OHB System AG will be carried out in cooperation with OHB Digital Connect GmbH and Airbus Defense and Space.

Gerhard Heiming

Related topics