Abstract
This paper presents a vicarious radiometric calibration of the Korea Multi-Purpose Satellite-3A (KOMPSAT-3A) performed by the Korea Aerospace Research Institute (KARI) and the Pukyong National University Remote Sensing Group (PKNU RSG) in 2015.The primary stages of this study are summarized as follows: (1) A field campaign to determine radiometric calibrated target fields was undertaken in Mongolia and South Korea. Surface reflectance data obtained in the campaign were input to a radiative transfer code that predicted at-sensor radiance. Through this process, equations and parameters were derived for the KOMPSAT-3A sensor to enable the conversion of calibrated DN to physical units, such as at-sensor radiance or TOA reflectance. (2) To validate the absolute calibration coefficients for the KOMPSAT-3A sensor, we performed a radiometric validation with a comparison of KOMPSAT-3A and Landsat-8 TOA reflectance using one of the six PICS (Libya 4). Correlations between top-of-atmosphere (TOA) radiances and the spectral band responses of the KOMPSAT-3A sensors at the Zuunmod, Mongolia and Goheung, South Korea sites were significant for multispectral bands. The average difference in TOA reflectance between KOMPSAT-3A and Landsat-8 image over the Libya 4, Libya site in the red-green-blue (RGB) region was under 3%, whereas in the NIR band, the TOA reflectance of KOMPSAT-3A was lower than the that of Landsat-8 due to the difference in the band passes of two sensors. The KOMPSAT-3Aensor includes a band pass near 940 nm that can be strongly absorbed by water vapor and therefore displayed low reflectance. Toovercome this, we need to undertake a detailed analysis using rescale methods, such as the spectral bandwidth adjustment factor.
Highlights
KOrea Multi-Purpose SATellite (KOMPSAT)-2 and -3 were commissioned to satisfy the demand for high-resolution satellite images in Korea
To evaluate the absolute calibration coefficient using a vicarious approach for KOMPSAT-3A, it was cross-validated with the Landsat-8 OLI sensor and TOA reflectance using the Libya-4 Pseudo Invariant Calibration Site (PICS)
In the NIR band, the average difference in TOA reflectance was 22% for the Libya site. This can be explained by the values in the band RSR of two sensors, which differed significantly from the NIR band and, unlike Landsat-8, the KOMPSAT-3A sensor reacted in a spectral region of 940 nm that is highly affected by water vapor absorption (Figure 5)
Summary
KOrea Multi-Purpose SATellite (KOMPSAT)-2 and -3 were commissioned to satisfy the demand for high-resolution satellite images in Korea. On March 26, 2015, KOMPSAT-3A was launched successfully, and Calibration and Validation (Cal/Val) began recently to improve image quality during the Launch and Early Operation Phase (LEOP). We report the results of the radiometric Cal/Val of the spectral application images. Post-launch in-flight calibration was conducted to promote the stable operation of KOMPSAT-3A during the LEOP. The study was comprised of three main stages: (1) A field campaign to determine radiometrically calibrated target fields was conducted in Mongolia and South Korea. Equations and parameters were derived for the KOMPSAT-3A sensor to enable conversion of calibrated DNs to physical units. (2) We assessed the calibration coefficients with radiometric validation by comparing KOMPSAT-3A and Landsat-8 TOA reflectance using a Pseudo Invariant Calibration Site (PICS) Equations and parameters were derived for the KOMPSAT-3A sensor to enable conversion of calibrated DNs to physical units. (2) We assessed the calibration coefficients with radiometric validation by comparing KOMPSAT-3A and Landsat-8 TOA reflectance using a Pseudo Invariant Calibration Site (PICS)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
