CAS500-1
Mission and sensor parameters
The Compact Advanced Satellite 500 1 (CAS500-1) is a Korean satellite under a research and development program of the Korean Aerospace Research Institute (KARI) and distributed by Korean National Geographic Information Institute (NGII). The CAS500 series developed by KARI is planning to have five 500kg-class CAS500 satellites having a standard platform and carrying different payloads. CAS500-1 carries the Advanced Electronic Image Scanning System C (AEISS-C) sensor that provides electro optical satellite imagery at very high resolution (at a resolution of 50 cm in panchromatic mode and of 2 metres in multispectral mode at a minimum swath width of 12 km). For the CAS500-1 mission, NGII is collecting, processing, managing, and distributing the high-resolution satellite images taken by CAS500 1st/2nd, and the application products. KARI is instead controlling the CAS500-1 satellite, receiving and processing raw images from the satellite. Charter owner Agency for CAS500-1 is KARI.
Mission parameters
Table 1 provides a summary of the CAS500-1 mission.
| Parameter | Specifications |
|---|---|
| EO Mission | Compact Advanced Satellite 500 1 |
| Mission Short name | CAS500-1 |
| Providing Agency | KARI, NGII |
| Date of launch | 22/03/2021 |
| Temporal coverage | 2021 - present |
| Mission status | onGoing |
| Mission lifetime | >2026 |
| Orbit type | Sun-synchronous |
| Equator Crossing Time | 11:00 (KST) |
| Orbit Height | 497.8 km |
| Orbit Period | 95 min |
| Orbit Inclination | 97.4 deg |
| Nominal Swath Width | >12 km at nadir |
Table 1 - CAS500-1 mission parameters.
Sensor specifications
CAS500-1 is equipped with the Advanced Electronic Image Scanning System (AEISS-C) sensor which has 0.5 m panchromatic and 2.0 multispectral geospatial resolution. This sensor is similar to the AEISS-A camera on board the KOMPSAT-3A. Acquisition modes are strip, spot and multi-path stereo.
| Parameter | Specifications |
|---|---|
| Instrument | AEISS-C |
| Spectral mode | Panchromatic and multispectral |
| Scanning technique | Pushbroom type imager |
| Resolution | Very High Resolution - O-VHR (0 - 1m) |
| GSD (nadir) | 0.5 m (panchromatic), 2 m (multispectral) |
| Swath width (nadir) | 12 km (nadir) |
| Radiometric Resolution | 12 bit/pixel |
Table 2 - CAS500-1 instrument technical specifications.
Wavelength, Center wavelength, Bandwidth (or FWHM), and common band name (CBN) for each spectral band of the CAS500-1 AEISS-C sensor are described in Table 3.
| Spectral Band (ID) | Spectral interval (nm) | Center Wavelength (µm) | Bandwidth or FWHM (µm) | CBN |
|---|---|---|---|---|
| PAN (Panchromatic) | 450-900 | 0.675 | 0.45 | pan |
| MS1 (Blue) | 450-520 | 0.485 | 0.07 | blue |
| MS2 (Green) | 520-600 | 0.560 | 0.08 | green |
| MS3 (Red) | 630-690 | 0.660 | 0.06 | red |
| MS4 (Near Infrared) | 760-900 | 0.830 | 0.14 | nir |
Table 3 - CAS500-1 spectral bands.
Geometric and radiometric processing
Processing levels of CAS500-1 are described in Table 4.
| Products | Level | Description |
|---|---|---|
| Standard | Level 1R | Radiometric corrected |
| Standard | Level 1G | Geometric corrected |
| Precision | Level 2R | Updated RPC of L1R using GCP Chip |
| Precision | Level 2G | Orthorectified imagery with precise DEM |
Table 4: CAS500-1 processing levels.
CAS500-1 L1G is the default product uploaded in COS-2.
Product description
Imagery and metadata formats
The CAS500-1 metadata file is given in XML format. The full resolution image product is provided as 12-bit single band GeoTIFF for each multispectral band.
Ingested format
Information extracted from product annotation included in the STAC item of a CAS500-1 L1G Dataset are listed below.
Properties
STAC item content about properties for a CAS500-1 L1G Dataset is the following:
"properties": {
"datetime": "2023-06-10T02:58:19.5969638Z",
"start_datetime": "2023-06-10T02:58:18.7535968Z",
"end_datetime": "2023-06-10T02:58:20.4403308Z",
"updated": "2025-10-09T13:11:51.3927395Z",
"platform": "cas500-1",
"constellation": "cas500",
"mission": "cas500-1",
"instruments": [
"aeiss-c"
],
"sensor_type": "optical",
"gsd": 0.5,
"metadata_format": "XML",
"data_file_format": "GEOTIFF",
"providers": [
{
"name": "NGII",
"description": "The National Land Satellite (CAS500-1: Compact Advanced Satellite 500) was exclusively developed in Korea through a collaboration between MOLIT and the Ministry of Science and ICT. It serves as a high-precision Earth observation satellite, designed for efficient land management and disaster response. The satellite is currently operated by the NGII.",
"roles": [
"producer",
"processor",
"licensor"
]
},
{
"name": "KARI",
"description": "The Compact Advanced Satellite 500 1 (CAS500-1) is a Korean satellite under a research and development program of the Korean Aerospace Research Institute (KARI).",
"roles": [
"licensor"
]
},
{
"name": "KARI",
"roles": [
"licensor"
]
}
],
"license": "proprietary",
"disaster:call_ids": [
777
],
"disaster:resolution_class": "VHR",
"cpe:cos2_id": "777-KARI-KOMPSAT3-CASS500-1-C1_20230610025814_12315_00049489_L1G"
}
Satellite
STAC item content about Satellite for a CAS500-1 L1G Dataset is the following:
"properties": {
"sat:absolute_orbit": 12315,
"sat:platform_international_designator": "2021-022A"
}
View
STAC item content about View for a CAS500-1 L1G Dataset is the following:
"properties": {
"view:off_nadir": 0,
"view:incidence_angle": 21.179062418,
"view:azimuth": 262.570041023,
"view:sun_azimuth": 33.8389050263393,
"view:sun_elevation": 60.9993374272084
}
EO
STAC item content about EO for a CAS500-1 L1G Dataset is the following:
"properties": {
"eo:cloud_cover": 0
}
Processing
STAC item content about Processing for a CAS500-1 L1G Dataset is the following:
"properties": {
"processing:level": "L1G",
"processing:software": {
"PMS": "C1LevelProcessor_v1.1.0_2022-03-22"
}
}
Projection
STAC item content about Projection for a CAS500-1 L1G Dataset is the following:
"properties": {
"proj:epsg": 32750,
"proj:wkt2": "PROJCS[\"WGS 84 / UTM zone 50S\", GEOGCS[\"WGS 84\", DATUM[\"World Geodetic System 1984\", SPHEROID[\"WGS 84\", 6378137, 298.257223563, AUTHORITY[\"EPSG\", \"7030\"]], AUTHORITY[\"EPSG\", \"6326\"]], PRIMEM[\"Greenwich\", 0, AUTHORITY[\"EPSG\", \"8901\"]], UNIT[\"degree\", 0.017453292519943295, AUTHORITY[\"EPSG\", \"9102\"]], AUTHORITY[\"EPSG\", \"4326\"]], UNIT[\"metre\", 1, AUTHORITY[\"EPSG\", \"9001\"]], PROJECTION[\"UTM50S\", AUTHORITY[\"EPSG\", \"32750\"]], PARAMETER[\"latitude_of_origin\", 0], PARAMETER[\"central_meridian\", 117], PARAMETER[\"scale_factor\", 0.9996], PARAMETER[\"false_easting\", 500000], PARAMETER[\"false_northing\", 10000000], AUTHORITY[\"EPSG\", \"32750\"], AXIS[\"East\", EAST], AXIS[\"North\", NORTH]]",
}
Geometry
STAC item content about Geometry for a CAS500-1 L1G Dataset is the following:
"geometry": {
"type": "Polygon",
"coordinates": [
[
[119.768744, -0.155859],
[119.793884, -0.280338],
[119.906736, -0.25769],
[119.881596, -0.133211],
[119.768744, -0.155859]
]
]
},
"bbox": [119.768744, -0.280338, 119.906736, -0.133211]
Assets
STAC item content about assets (annotation, quicklooks and spectral bands files harvested from the source product) and EO bands for a CAS500-1 L1G Dataset is the following:
"assets": {
"metadata": {
"type": "application/xml",
"roles": [
"metadata"
],
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/metadata.xml",
"filename": "C1_20230610025814_12315_00049489_L1G_Aux.xml",
"file:size": 111347
},
"overview": {
"type": "image/jpeg",
"roles": [
"overview"
],
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/overview.jpg",
"filename": "C1_20230610025814_12315_00049489_L1G_br.jpg",
"file:size": 161617
},
"thumbnail": {
"type": "image/jpeg",
"roles": [
"thumbnail"
],
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/thumbnail.jpg",
"filename": "C1_20230610025814_12315_00049489_L1G_th.jpg",
"file:size": 4579
},
"L1G-P": {
"type": "image/tiff",
"roles": [
"data",
"dn"
],
"title": "L1G Panchromatic",
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/L1G-P.tif",
"filename": "C1_20230610025814_12315_00049489_L1G_P.tif",
"file:size": 1904324566,
"gsd": 0.5,
"proj:shape": [28920, 32920],
"raster:bands": [
{
"scale": 0.071,
"offset": -33.653
}
],
"eo:bands": [
{
"name": "Panchromatic",
"common_name": "pan",
"center_wavelength": 0.675,
"full_width_half_max": 0.45,
"solar_illumination": 1258.38
}
]
},
"L1G-B": {
"type": "image/tiff",
"roles": [
"data",
"dn"
],
"title": "L1G Blue",
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/L1G-B.tif",
"filename": "C1_20230610025814_12315_00049489_L1G_B.tif",
"file:size": 119064046,
"gsd": 2,
"proj:shape": [7230, 8230],
"raster:bands": [
{
"scale": 0.096,
"offset": -39.468
}
],
"eo:bands": [
{
"name": "Blue",
"common_name": "blue",
"center_wavelength": 0.485,
"full_width_half_max": 0.07,
"solar_illumination": 1984.65
}
]
},
"L1G-G": {
"type": "image/tiff",
"roles": [
"data",
"dn"
],
"title": "L1G Green",
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/L1G-G.tif",
"filename": "C1_20230610025814_12315_00049489_L1G_G.tif",
"file:size": 119064046,
"gsd": 2,
"proj:shape": [7230, 8230],
"raster:bands": [
{
"scale": 0.084,
"offset": -38.798
}
],
"eo:bands": [
{
"name": "Green",
"common_name": "green",
"center_wavelength": 0.56,
"full_width_half_max": 0.08,
"solar_illumination": 1815.54
}
]
},
"L1G-R": {
"type": "image/tiff",
"roles": [
"data",
"dn"
],
"title": "L1G Red",
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/L1G-R.tif",
"filename": "C1_20230610025814_12315_00049489_L1G_R.tif",
"file:size": 119064046,
"gsd": 2,
"proj:shape": [7230, 8230],
"raster:bands": [
{
"scale": 0.107,
"offset": -25.667
}
],
"eo:bands": [
{
"name": "Red",
"common_name": "red",
"center_wavelength": 0.66,
"full_width_half_max": 0.06,
"solar_illumination": 1536.38
}
]
},
"L1G-N": {
"type": "image/tiff",
"roles": [
"data",
"dn"
],
"title": "L1G Near Infrared",
"href": "https://.../datasets/C1_20230610025814_12315_00049489_L1G/L1G-N.tif",
"filename": "C1_20230610025814_12315_00049489_L1G_N.tif",
"file:size": 119064046,
"gsd": 2,
"proj:shape": [7230, 8230],
"raster:bands": [
{
"scale": 0.094,
"offset": -42.437
}
],
"eo:bands": [
{
"name": "Near Infrared",
"common_name": "nir",
"center_wavelength": 0.83,
"full_width_half_max": 0.14,
"solar_illumination": 967.99
}
]
}
}
Product Calibration
For CAS500-1 products calibration refer to the Optical Products Calibration (OPT-Calib) service and the calibration sheet available here.
References
[^1] T. -H. Kim, Y. Park, S. Jang and C. -S. Yang, "Ship Detection and Classification in Cas500-1 Images Based on Yolo Model," IGARSS 2023 - 2023 IEEE International Geoscience and Remote Sensing Symposium, Pasadena, CA, USA, 2023, pp. 4112-4115. DOI: 10.1109/IGARSS52108.2023.10282491.
[^2] J. Oh, H. Ji, H. J. Yang, J. I. Hwang, and C. Lee, “Large scale topographic mapping using stereo pair imagery from CAS500–1 satellite,” KSCE J. Civil Eng., vol. 27, no. 3, pp. 1288–1297, Mar. 2023. DOI: 10.1007/s12205-022-1827-1.
[^3] Seo, W. W., Yoon, W. S., Kang, H., Lim, P. C., and Kim, T.: DEVELOPMENT OF CLOUD DETECTION METHOD FOR CAS500-1 IMAGERY, Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVIII-1/W2-2023, 1537–1543, https://doi.org/10.5194/isprs-archives-XLVIII-1-W2-2023-1537-2023, 2023.
[^4] Seoyeon Kim, & Yangwon Lee (2023). Atmospheric Correction of CAS500-1 Images using 6SV-based AI Model. The Geographical Journal of Korea, 57(4), 587-595. 10.22905/kaopqj.2023.57.4.16