KOMPSAT-3
KOMPSAT-3 (Korean Multi-purpose Satellite-3), also known as Arirang-3,[2] is a South Korean multipurpose Earth observation satellite. It was launched from Tanegashima Space Center, Japan at 16:39 UTC on 17 May 2012. Like the earlier KOMPSAT-1 and KOMPSAT-2 satellites, it takes its name from the popular Korean folk song Arirang. Its launch was the culmination of a project begun in 1995.[3]
| Names | Korean Multi-purpose Satellite-3 Arirang-3 | 
|---|---|
| Mission type | Earth observation | 
| Operator | Korea Aerospace Research Institute | 
| COSPAR ID | 2012-025B | 
| SATCAT no. | 38338 | 
| Mission duration | 4 years (planned) 9 years and 10 months (in progress) | 
| Spacecraft properties | |
| Spacecraft type | KOMPSAT | 
| Manufacturer | Korea Aerospace Research Institute EADS Astrium (bus) | 
| Launch mass | 980 kg (2,160 lb) | 
| Dimensions | 2.9 m in diameter x 3.5 m in height | 
| Power | 1.3 kW | 
| Start of mission | |
| Launch date | 17 May 2012, 16:39 UTC | 
| Rocket | H-IIA (202) (# 21) | 
| Launch site | Tanegashima Space Center | 
| Contractor | Mitsubishi Heavy Industries | 
| Entered service | 29 March 2013 | 
| Orbital parameters | |
| Reference system | Geocentric orbit[1] | 
| Regime | Sun-synchronous orbit | 
| Altitude | 685 km (426 mi) | 
| Inclination | 98.13° | 
| Period | 98.5 minutes | 
| Instruments | |
| Advanced Earth Imaging Sensor System (AEISS) | |
| KOMPSAT programme | |
KOMPSAT-3 orbits at a height of 685.1 km (425.7 mi), circling the Earth 14 times per day, and is expected to maintain that orbit for 4 years. It weighs 980 kg (2,160 lb). The satellite carries a Advanced Earth Imaging Sensor System (AEISS), which can distinguish to a 70-cm resolution, allowing the identification of individual vehicles on the ground.[4]
The satellite was succeeded by KOMPSAT-5 and KOMPSAT-3A, which were launched on 2013 and 2015 respectively.
History
    
South Korea started the KOMPSAT programme in 1995 to nurture its national Earth-imaging industry and supply services for remote-sensing applications. The South Korean KOMPSAT-3 Earth-imaging satellite was developed by Korea Aerospace Research Institute (KARI), in partnership with EADS Astrium, to assure continuity with the KOMPSAT-2 satellite launched in 2006. KOMPSAT-3 was orbited on 17 May 2012 by a launch vehicle from Tanegashima Space Center, Japan. SI Imaging Services is the worldwide exclusive distributor of KOMPSAT imagery since November 2012.[4]
Technologies
    
    Orbit
    
KOMPSAT-3 operates in a near-polar, circular Sun-synchronous orbit. The orbital parameters are:
- Mean altitude: 685.1 km
- Mass: 980 kg
- Inclination: 98.13° (Sun-synchronous orbit)
- Orbital period: 98.5 minutes
- Orbital cycle: 28 days
Instruments
    
KOMPSAT-3's instruments are designed to acquire high- and very-high-resolution imagery with a footprint of 16.8 km. The satellite has the capacity to acquire 20 minutes of imagery on each orbit and it can steer its sensors both ways out to 30° off track. Panchromatic and multispectral images can be acquired at the same time.
KOMPSAT-3 radiometer features:
| mode | Channel | Spectral band | Spatial resolution | Footprint | 
|---|---|---|---|---|
| Multispectral | 1 | 0.45 - 0.52 μm (blue) | 2.8 m | 16.8 km | 
| 2 | 0.52 - 0.60 μm (green) | 2.8 m | 16.8 km | |
| 3 | 0.63 - 0.69μm (rouge) | 2.8 m | 16.8 km | |
| 4 | 0.76 - 0.90 μm (near-infrared) | 2.8 m | 16.8 km | |
| Panchromatic | P | 0.50 - 0.90 μm (black and white) | 70 cm | 16.8 km | 
Ground receiving stations
    
Two receiving stations deliver KOMPSAT-3 imagery 1 to 3 days after acquisition. The Deajeon station in South Korea is responsible for tasking the satellite.
Advantages and applications of KOMPSAT-3 imagery
    
KOMPSAT-3 is designed for very-high-resolution (VHR) remote-sensing applications, such as:
- Land planning: to detect and identify features smaller than 1 square meter, e.g. vehicles, street furnishings, roads and bushes
- Agriculture: to pinpoint crop or tree diseases
- Urban planning and demographics: to locate detached houses
- Civil engineering: to plan road, railroad and oil pipeline corridors
- Defence: to describe high-value assets or military sites
South Korea
    
It serves along with the existing Kompsat-2 to provide continuous satellite observation of the Korean Peninsula, sending images twice a day at 01:30 and 13:30.[5]
References
    
-  "Trajectory: Kompsat 3 2012-025B". NASA. 21 October 2021. Retrieved 22 October 2021.  This article incorporates text from this source, which is in the public domain. This article incorporates text from this source, which is in the public domain.
- "KOMPSAT 3 (Arirang 3)". Gunter's Space Page. 7 July 2020. Retrieved 22 October 2021.
- "KOMPSAT-1". ESA eoPortal Directory. 2021. Retrieved 22 October 2021.
- "KOMPSAT-3". ESA eoPortal Directory. 2021. Retrieved 24 October 2021.
- "Arirang-3 launch lifts Korea's space program". Korea Herald. 19 June 2012. Retrieved 24 October 2021.
