KOMPSAT-5

Mission and sensor parameters

KOMPSAT-5 (KOrea Multi-Purpose SATellite-5) is the first Korean SAR satellite designed and manufactured by the Korean space agency (KARI). KOMPSAT-5 payload includes the COSI (Corea SAR Instrument) multi-mode X-band (9.66 GHz) SAR instrument¹,²,³.

Mission parameters

KOMPSAT-5 was launched on 22 August 2013. The satellite carries a X-band SAR instrument, Corea SAR Instrument (COSI), which provides imagery in all polarisations (HH,HV,VV,VH). In the Charter Governance KARI acts as mission owner of KOMPSAT-5.

Table 1 provides a summary of the KOMPSAT-5 mission.

Sensor specifications

Table 2 provides specifications of the Corea SAR Instrument (COSI) earth observation sensor on board the KOMPSAT-5 platform. COSI is a multi-mode X-band instrument provided by TAS-I (Thales Alenia Space-Italy)⁴.

Imaging Modes

KOMPSAT-5 COSI SAR imaging modes³ are:

• HIGH RESOLUTION (HR), ENHANCED HIGH RESOLUTION (EH), and ULTRA HIGH RESOLUTION (UH),

• STANDARD (ST), and ENHANCED STANDARD (ES),

• WIDE SWATH (WS), ENHANCED WIDE SWATH (EW).

In the following Table 3 a brief summary of the main imaging characteristics of all Kompsat-5 modes is given.

Default product

KARI contributes to the Charter with the provision of radiometrically calibrated, geocoded and georeferenced radar data from KOMPSAT-5 satellite. Imported Dataset in the ESA Charter Mapper from COS-2 are SAR Geocoded Terrain Corrected (GTC) L1D products. KOMPSAT-5 GTC L1D GTC SAR product provides Backscattering coefficient of the observed scene, multi looked (but for High Resolution Mode), with the Incidence Angles Mask (GIM layer).

Native format

KOMPSAT-5 GTC L1D acquisitions are provided to the Charter as a compressed archive containing:

• an XML metadata file
• a GeoTIFF file for single-band L1D product at chosen polarization
• a GeoTIFF file of the GIM (Geocoded Incidence Mask)
• a JPG file with a browse image
• a PNG file with a quicklook
• a KML file of Scene Quicklook Map Overlay

Ingested format

During the ingestion key information is extracted from product annotation and included in the STAC item of a KOMPSAT-5 dataset. Below is given an example of the information contained into the STAC item of a KOMPSAT-5 GTC ST product in VV polarization received during the Charter Activation 787 (COS-2 ID: 907-KARI-KOMPSAT5-urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml).

Properties

STAC item content about properties for a KOMPSAT-5 GTC ST Dataset is the following:

  "properties": {
    "platform": "kompsat-5",
    "mission": "kompsat-5",
    "instruments": [
      "cosi"
    ],
    "sensor_type": "radar",
    "gsd": 3,
    "datetime": "2022-10-09T23:19:07Z",
    "created": "2022-10-20T08:48:25.0059181Z",
    "updated": "2022-11-30T14:06:03.2721351Z"
    "title": "KOMPSAT-5 GTC ST VV 2022-10-09 23:19:07",
    "providers": [
      {
        "name": "KARI",
        "roles": [
          "licensor"
        ]
      }
    ],
    "license": "proprietary",
    "disaster:call_ids": [
      907
    ],
    "disaster:resolution_class": "HR",
    "cpe:cos2_id": "907-KARI-KOMPSAT5-urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml",
  }

View

STAC item content about View Geometry for a Kompsat-5 GTC ST Dataset is the following:

  "properties": {
    "view:incidence_angle": 37.64450498856029,
    "view:off_nadir": 34.14044541120529
  }

Satellite

STAC item content about Satellite for a Kompsat-5 GTC ST Dataset is the following:

  "properties": {
    "sat:absolute_orbit": 50150,
    "sat:orbit_state": "ascending"
  }

SAR

STAC item content about SAR for a Kompsat-5 GTC ST Dataset is the following:

  "properties": {
    "sar:instrument_mode": "ST",
    "sar:frequency_band": "X",
    "sar:polarizations": [
      "VV"
    ],
    "sar:product_type": "GTC",
    "sar:observation_direction": "right",
    "sar:center_frequency": 9.66,
    "sar:resolution_range": 3.769912456206589,
    "sar:resolution_azimuth": 2.561736484147257,
    "sar:pixel_spacing_range": 1.125,
    "sar:pixel_spacing_azimuth": 1.125,
    "sar:looks_range": 1,
    "sar:looks_azimuth": 1,
    "sar:looks_equivalent_number": 1,
  }

Processing

STAC item content about Processing for a Kompsat-5 GTC ST Dataset is the following:

  "properties": {
    "processing:level": "L1D"
  }

Geometry

STAC item content about Geometry for a Kompsat-5 GTC ST Dataset is the following:

  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [
        [
          100.4407808877117,
          13.829065567495038
        ],
        [
          100.43878245924638,
          13.499942034214016
        ],
        [
          100.7740751312714,
          13.497794095861195
        ],
        [
          100.77653873162318,
          13.826863276312572
        ],
        [
          100.4407808877117,
          13.829065567495038
        ]
      ]
    ]
  },
  "bbox": [
    100.43878245924638,
    13.497794095861195,
    100.77653873162318,
    13.829065567495038
  ]

Assets

STAC item content about assets (annotation, quicklooks and spectral bands files harvested from the source product) and EO bands for a Kompsat-5 GTC ST Dataset is the following:

  "assets": {
    "thumbnail": {
      "type": "application/octet-stream",
      "roles": [
        "thumbnail"
      ],
      "title": "Acquisition Thumbnail",
      "href": "https://.../907-KARI-KOMPSAT5-urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml/thumbnail"
    },
    "overview": {
      "type": "application/octet-stream",
      "roles": [
        "overview"
      ],
      "title": "Acquisition Overview",
      "href": "https://.../907-KARI-KOMPSAT5-urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml/overview"
    },
    "enclosure": {
      "type": "application/octet-stream",
      "roles": [
        "data"
      ],
      "title": "Acquisition Enclosure",
      "href": "https://.../907-KARI-KOMPSAT5-urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml/enclosure",
      "file:size": 1013946225,
      "filename": "urn_ogc_def_EOP_KARI_KOMPSAT5_K5_20221009231907_000010_50150_A_ST08_VV_GTC_B_L1D_Aux_xml-product.zip"
    }
  }

Product Calibration

For KOMPSAT-5 products calibration refer to the Radar Products Calibration (SAR-Calib) service and the calibration sheet available here.