KOMPSAT-5

Long name Korea Multipurpose Satellite-5
Short name Kompsat-5
Sensor type Synthetic-aperture radar (SAR)
Platform Korea Multipurpose Satellite-5
Frequency 9.66 GHz
Band (wavelength) X (3.10 cm)
Polarization HH, HV, VH, VV
Key file name (use to open data set) *.h5, *_Aux.xml
Supported file extensions *.h5, *.xml
Data distributor Satrec Initiative Imaging Services (SIIS)
Sections

Data product name and description
Distribution disk files
Returned data for supported format
References

Data product name and description

KOMPSAT-5 has three basic acquisition modes:
  • High-resolution (Spotlight) HR
  • Standard (Stripmap) ST
  • Wide Swath (ScanSar) WS

Each mode has various resolution classes and processing levels, as described in the following tables.

Note: The information provided herein is based on the KOMPSAT-5 reference documentation cited in References.
Mode Swath width (km) Resolution (range x azimuth, m)* Polarization Description/notes
High Resolution [HR] ≈18

[HR] ≈1.0 x 1.0
[HR-EH] ≈1.0 x 1.0
[HR-UH] ≈0.85 x 0.85

Single (HH or HV or VH or VV) In each imaging mode, the antenna steers (in the azimuth plane) during overall acquisition time to illuminate the required scene longer than the side view of the standard strip. In addition to HR mode, two enhanced HR modes can be selected:
  • HR-EH: Enhanced High Resolution mode. In this mode, a uniform resolution of approximately 1 meter in range direction is provided.
  • HR-UH: Ultra High Resolution mode. In this mode, a range and azimuth resolution of 0.85 meters is provided.
Standard [ST] ≈30

[ST] ≈3.0 x 3.0
[ST-ES] ≈2.5 x 2.5

Single (HH or HV or VH or VV) In each imaging mode, the antenna steers in a fixed direction in relation to the flight path of the platform. The antenna footprint covers a strip on the illuminated surface as the platform moves and the system operates. In addition to ST mode, one enhanced ST mode can be selected:
  • ST-ES: Enhanced Standard mode. In this mode, a greater range resolution of 2.5 meters is provided.
Wide Swath [WS] ≈100

[WS] ≈20 x 20
[WS-EW] ≈5 x 5

Single (HH or HV or VH or VV) In each imaging mode, imagery is acquired in a larger swath than Standard mode, but with lower spatial resolution. A larger range swath is obtained by periodically stepping the antenna beam to neighboring sub-swaths. In this mode, only a part of the synthetic-antenna length is available in azimuth and, consequently, the azimuth resolution is reduced. In addition to WS mode, one enhanced WS mode can be selected:
  • WS-EW: Enhanced Wide Swath mode. In this mode, the radiometric resolution is improved by implementation of a significant increase in radiometric resolution in the range from 20 meters through 5 meters. During image processing, a multilook technique (four looks) is applied to improve image uniformity.

* Resolution is always single-look complex (SLC) unless noted otherwise.

All acquisition modes have five processing levels. Level 1A, Level 1B, Level 1C, and Level 1D are supported.

Each acquisition mode is described in the following table.

Processing level Acquisition mode Description/notes
Level 0 (RAW) N/A Level 0 is not supported.

Level 1A
Single-look complex (SCS)

[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]
[WS], [WS-EW]

In-phase and quadrature-focused data, weighted, and radiometrically equalized versus slant-range losses.
Projection: Slant range/azimuth (zero-Doppler)

Level 1B
(DGM)

N/A

Amplitude of the focused data, multilooked (except High Resolution mode).
Projection: Ground range (WGS84 ellipsoid)/azimuth (zero-Doppler)

Note: This acquisition mode is discontinued.

Level 1C
Geocoded Earth ellipsoid
(GEC, WEC)

[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]
[WS], [WS-EW]

Amplitude of the focused data, multilooked (except High Resolution mode). Use of the ellipsoid for the estimation of antenna pattern and incidence angle, map projection on the ellipsoid.
Projection: UTM (–80° ≤ center latitude ≤84°) or UPS

  • The GEC product contains, for each sensor acquisition mode, the focused data, detected, geolocated on the reference ellipsoid and represented in cartographic projection (UTM or UPS depending on the scene center).
  • WEC products have the same features as GEC products, but for geographical coordinates system (GEOG) projection.

Level 1D
Geocoded Earth terrain
(GTC, WTC)

[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]
[WS], [WS-EW]

Backscattering coefficient of the observed scene, multilooked (except High Resolution mode), with the incidence angle mask annexed.
Fully calibrated with terrain model (DEM1), detected, geolocated on a DEM and represented cartographic projection.
Projection: UTM (–80° ≤ center latitude ≤84°) or UPS

  • The GTC product contains, for each sensor acquisition mode, the focused data fully calibrated with terrain model detected, geolocated on a DEM and represented cartographic projection (UTM or UPS depending on the scene center). The planimetric accuracy of the product will depend on the accuracy of the DEM.
  • WTC products have the same features as GTC products, but for GEOG projection.

Distribution disk files

KOMPSAT-5 data is distributed in two formats: HDF5 and GeoTIFF.

Table 1. HDF5
File name Format Required Contents/details
*.h5 HDF5 (Hierarchical Data Format) Yes Contains image data and metadata
*_Aux.xml Extensible Markup Language No Contains image metadata (same metadata as HDF5 file)
*.pdf Portable Document Format No N/A
*_br.jpg Joint Photographic Experts Group No Browse image
*_th.jpg Joint Photographic Experts Group No Thumbnail image

Table 2. GeoTIFF
File name Format Required Contents/details
*.tif GeoTIFF Yes Contains image data and metadata
Note: With complex data, there are two bands.
*_Aux.xml Extensible Markup Language Yes Contains image metadata (ancillary data)
*.pdf Portable Document Format No End-user license agreement (EULA)
*.kml Keyhole Markup Language No Quick-look image in KML format
*_br.jpg Joint Photographic Experts Group No Browse image
_QL.png Portable Network Graphics No Quick-look image
*_th.jpg Joint Photographic Experts Group No Thumbnail image

Returned data for supported format

KOMPSAT-5 data can be opened directly in its raw vendor format or imported into a PCIDSK (*.pix) file using the key file (*.h5 or *_Aux.xml). For optimal processing, use the PCIDSK format.

In the following table, the data structure after it is imported into a PCIDSK file is described. Information is provided on only the fully supported processing levels and acquisition modes.

Warning: Data sets for this sensor are organized in a specific folder structure on disk. GDB uses this structure and the file names to identify the data product type. Do not alter the folder structure or any file names prior to data ingestion to ensure the image data and auxiliary information are imported correctly.
Data product Data returned Details

Level 1A
Single-look complex (SCS)
[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]

SCS_A
1 x [C32R] Raster channel

1 x [ORB] Orbit segment
1 x [BIN] Rational function model
1 x [ARR] Incidence angle array

SCS_B, SCS_W
1 x [C16S] Raster channel

1 x [ORB] Orbit segment
1 x [BIN] Rational function model
1 x [ARR] Incidence angle array

For more information about SCS_A, SCS_B and SCS_W products, see the documentation cited in References.

Level 1A
Single-look complex (SCS)
[WS], [WS-EW]

SCS_A
<swath_no> x [C32R] Raster channel or channels

<swath_no> x [ORB] Orbit segment or segments
<swath_no> x [BIN] Rational function model or models
<swath_no> x [ARR] Incidence angle array or arrays

SCS_B, SCS_U
<swath_no> x [C16S] Raster channel or channels

<swath_no> x [ORB] Orbit segment or segments
<swath_no> x [BIN] Rational function model or models
<swath_no> x [ARR] Incidence angle array or arrays

One channel, one orbit segment and one incidence angle array segment per swath
Note: <swath_no> represents the number of subswaths (3, 4, 5...)

Level 1C
[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]
[WS], [WS-EW]

GEC_A, WEC_A
1 x [32R] Raster channel

1 x [ORB] Orbit segment
1 x [ARR] Incidence angle array

GEC_B, GEC_W, WEC_B, WEC_W
1 x [C16U] Raster channel

1 x [ORB] Orbit segment
1 x [ARR] Incidence angle array

N/A

Level 1D
[HR], [HR-EH], [HR-UH]
[ST], [ST-ES]
[WS], [WS-EW]

GTC_A, WTC_A
1 x [32R] Raster channel

1 x [ORB] Orbit segment
1 x [ARR] Incidence angle array

GTC_B, GTC_W, WTC_B, WTC_W
1 x [C16U] Raster channel

1 x [ORB] Orbit segment
1 x [ARR] Incidence angle array

N/A

References

KOMPSAT-5 after a thorough (SIC) facelift. SI imaging Services. 2015. Nine pages.
Note: An online version of the preceding document is available online under the name "KOMPSAT-5 after a through facelift" at si-imaging.com/resources.

KOMPSAT-5 Product Specifications. Standard Products Specifications. Korea Aerospace Research Institute, SI Imaging Services Co., LTD. Version 1.2. July, 2015. 58 pages.

KOMPSAT-5 Product Attributes. Products Attributes Specification. Korea Aerospace Research Institute, SI Imaging Services Co., LTD. Version 1.2. July, 2015. 71 pages.

KOMPSAT-5 Image Data Manual. Korea Aerospace Research Institute, SATREC Initiative Co., LTD. V1.0/2014.04.01. 43 pages.

KOMPSAT-5 Product Attributes. Korea Aerospace Research Institute, SATREC Initiative Co., LTD. V1.0/2014.04.01. 71 pages.

1 digital elevation model

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