KOMPSAT 6 (Arirang 6)

KOMPSAT 6 [KARI]

KOMPSAT 6 (Korean Multi-purpose Satellite 6) or Arirang 6 (아리랑 6) is a planned Korean sub-meter class SAR Satellit.

The high-resolution imaging radar for South Korea’s Kompsat-6 Earth observation satellite will be built by LIG Nex1 Co. Ltd. of Korea and Airbus Defence and Space’s German arm. It provides a 0.5 m ground resolution.

KOMPSAT 6's payload consists of the XSAR (X-Band Synthetic Aperture Radar) and S-AIS (Satellite-Automatic Identification System) payloads (Satellite-Automatic Identification System). XSAR is a high-resolution all-weather radar imager with applications in mapping, GIS, environmental and disaster monitoring, and ocean and land management. The S-AIS payload is a maritime wireless system that identifies the position, heading, destination, and cargo of larger vessels for the purpose of preventing collisions between larger vessels and for other applications in maritime traffic management.

XSAR consists of the SSS (SAR Sensor Subsystem), DLS (Data Link Subsystem), and PLM (Payload Module). The SSS is made up of the (SAR controller electronics), which is in charge of the SSS's command and control, the RFE (Radio Frequency Electronics), which performs frequency up-converting and bandwidth multiplication for signal transmission, as well as down-converting and I/Q demodulating for signal reception, the FEI (Front End Interface), which provides RF (Radio Frequency) signal routing, the SAA (SAR Antenna Assembly), an active phased array, and (Antenna Power Supply). The DLS is responsible for data storage, handling, and transmission, whereas the PLM is made up of the structure, thermal control hardware, and harness.

XSAR has four operational modes: High Resolution A, High Resolution B, Standard, and Wide Swath with spatial resolutions of 0.5 m, 1.0 m, 3.0 m, and 20 m and swath widths of 5 km, 10 km, 30 km, and 100 km, respectively. The operating frequency of the instrument is 9.66 GHz (X-band), with a wavelength of 320 mm and an incidence angle of 20°- 60°. It has a 1 Tbit onboard storage capacity and can perform single, double, or quad multi-polarisation (HH, HV, VH, VV). S-AIS operates in the VHF (Very High Frequency) band and has a data memory of 4 GB.

The satellite was to be launched in 2020 (delayed to 2022 on a Russian Angara-1.2 rocket as a successor and replacement for the KOMPSAT 5 satellite. Due to sactions resulting from the Russian invasion of Ukraine, the launch on a Russian launch vehicle was cancelled. As a replacement, an Arianespace Vega-C launch was ordered.