ASELSAN brings national technologies to the country with its investments in satellite technologies.
In line with Turkey’s recent satellite/space roadmap, ASELSAN accelerated its work on satellite technologies and assumed important roles with its products and services in different components of satellite technologies. ASELSAN has made a series of moves in the field of satellite technologies in line with the National Technology Move approach, which includes critical technologies that will increase Turkey’s global competitiveness and ensure its economic and technological independence.
Focused on space technologies
Satellite communication systems were ready in the 2000s. With the national solutions in recent years, foreign dependency on this issue has disappeared.
With the project support under the coordination of the Presidency of Defense Industry, satellite modems, RF systems, antenna systems, software, equipment that will provide the communication infrastructure in satellite systems have been enriched with the ecosystem established with local and national companies.
During these studies, studies were carried out in intensive cooperation with universities as well as sub-industry and SMEs. ASELSAN continued to increase its new technologies and designs in the field of satellite technologies.
ASELSAN is in the field with its national and reliable satellite communication solutions, including satellite ground control centers for land, air and sea platforms, covering the increasing needs in Turkey and abroad.
The company, within the framework of the general classification for space systems, as a strategic target for space and satellite technologies; It continues to work intensively on payload and communication subsystems in the space segment (orbiting spacecraft and/or satellite), fixed and portable ground stations and control centers in the ground segment, and satellite communication terminals for all platforms.
The solution to the need for high speed data download from satellite
One of ASELSAN’s studies on satellite/space technologies was implemented for the High Speed X-Band Transmitter Unit.
While the earth observation satellites are moving in low orbit (LEO), they can download images when they enter the field of view of the ground station. Satellites operating in orbit with an altitude of 500-800 kilometers move at an average speed of 7.5 kilometers per second and can stay in the field of view of a ground station located in Ankara for an average of 8 to 10 minutes. The speed at which images are downloaded is critical, as the timeframes during which the viewing angle is provided are limited.
The distance between the satellite and the ground station is greater when the satellite enters and exits the field of view of the ground station, and the distance between the satellite and the ground station decreases when it approaches the ground station and passes over the ground station.
If there is no change in the characteristics of the communication channel during the transit of the satellite, it is possible to obtain higher data rates at close distances than at long distances. The systems used in existing LEO satellites and broadcasting in X-band download with a constant data rate while in view of the ground station. This hinders the possibility of downloading data at higher speeds as the satellite approaches the ground station and passes just over the top of the ground station.
In parallel with the developing satellites and remote sensing technologies, the dimensions of the images created by these satellites are also increasing. The frequency band allocated in the X-band for earth observation satellites by the International Telecommunication Union (ITU) is fixed and covers the 8025 MHz-8400 MHz range. This prevents the use of more bandwidth and encourages the use of different technologies for more efficient use of the existing 375 MHz frequency band.
The High Speed X-Band Transmitter Unit, developed by ASELSAN, uses the frequency band more efficiently than traditional transmitters and offers maximum data download opportunity while passing over the ground station with its variable data rate support.
The data, which is downloaded from the satellite to the ground station in an average of 2 units with the traditional transmitter units, can be downloaded in 1 unit time with the High Speed X-Band Transmitter Unit, while the satellite is moving in its orbit. In addition, the total amount of data downloaded with the High Speed X-Band Transmitter Unit during the entire transition period is 1.5 times higher than with conventional transmitter units.
