Arirang 5 is Korea's first earth observation satellite equipped with a Synthetic Aperture Radar (SAR) for all-weather ground and ocean observations above the Korean Peninsula.
The SAR mounted in Arirang 5 emits a microwave to an object on the ground and synthesizes the reflected signal to produce the image. It enables ground observation even during nighttime and poor weather. As part of Arirang 5's development, KARI developed a significant portion of its technology, excluding its main core technology, with domestic technology. The imaging radar payload’s core technology was developed through technical cooperation with overseas partners since it was not available in Korea. Through the development of Arirang 5, KARI was able to secure the technology related to imaging radar and imaging radar correction and processing technology.
Arirang 5 added four operational modes—improved high-resolution mode with resolution of 1m (observation width of 3 ㎞×3 ㎞), ultra-high-resolution mode of 0.85 m (2.7㎞×2.7㎞), enhanced standard-resolution mode of 2.5m (30 ㎞), and enhanced wide-area observation mode of 20 m (100 km)—through post-launch performance improvement to provide improved high-resolution, high-quality images.
| Subject | Imaging Radar Payload | Remarks |
|---|---|---|
| Mass | 520kg | Excluding the mass of the payload module structure |
| Maximum power consumption | 1700W | - |
| Incident angle | 20 - 55˚ | - |
| Standard-resolution mode | 3 m (resolution) / 30 km (observation width) | Based on incident angle of 45˚ |
| High-resolution mode | 1 m (resolution) / 5 km (observation width) | Based on incident angle of 45˚ |
| Wide-area observation mode | 20 m (resolution) / 100 km (observation width) | Based on incident angle of 45˚ |
| Polarized observation | Selected observation among HH, HV, VH, and VV | - |
| Image acquisition time | Average of two minutes per orbit | Time for longitudinal observation of the Korean Peninsula |
| Image storage capacity | 256Gbit | - |
| Image transmission capacity | 310Mbps | Real-time transmission of observed images of the Korean Peninsula |
| Country | Satellite | Resolution | Altitude | Weight | Year Launched |
|---|---|---|---|---|---|
| Germany | TerraSAR-X | 1m, 3m, 16m | 514km | 1,230kg | 2007 |
| TanDEM-X | 1m∼16m | 514km | 1,330kg | 2010 | |
| Italy | Cosmo-SkyMed-3 | ≤1m, 3m∼100m | 619km | 1,700kg | 2008 |
| Cosmo-SkyMed-4 | ≤1m, 3m∼100m | 619km | 1,700kg | 2010 | |
| Israel | TecSAR-1 | ≤1m, 3m, 8m | 550km | 300kg | 2008 |
| Russia | Kondor-E1 | 1m ~ 3m | 550km | 800kg | 2010 |
The development of Arirang 5 enabled securing not only existing optical images but also all-weather, day and night radar images as demanded in Korea. Arirang 5 is capable of all-weather observation and is used in national disasters and emergency management by complementing the optical and IR images of Arirang 2, Arirang 3, and Arirang 3A. The images of Arirang 5 can be used for geographic information systems (GIS), ocean observation, ground observation, disaster monitoring, and environmental monitoring. They are currently used for land and urban planning, water resources, agriculture, ocean, forestry, environment, map production, and geological resource utilization.
The development of Arirang 5 opened an opportunity to secure the basis for the development of the Arirang 6 imaging radar with resolution of 50 cm with Korean technologies and imaging radar correction and processing technologies. Arirang 5 has successfully completed its mission for five years, operating for an extended period of 2 years as of 2019.