The Intercomparison of X-Band SAR Images from COSMO‑SkyMed and TerraSAR-X Satellites: Case Studies

Abstract

Abstract:The analysis of experimental data collected by X-band SAR of COSMO-SkyMed (CSK®) and TerraSAR-X (TSX) images on the same surface types has shown significant differences in the signal level of the two sensors. In order to investigate the possibility of combining data from the two instruments, a study was carried out by comparing images collected with similar orbital and sensor parameters (e.g., incidence angle, polarization, look angle) at approximately the same date on two Italian agricultural test sites. Several homogenous agricultural fields within the observed area common to the two sensors were selected. Some forest plots have also been considered and used as a reference target). Direct comparisons were then performed between CSK and TSX images in different acquisition modes. The analysis carried out on the agricultural fields showed that, in general, the backscattering coefficient is higher in TSX Stripmap images with respect to CSK-Himage (about 3 dB), while CSK-Ping Pong data showed values lower than TSX of about 4.8 dB. Finally, a difference in backscattering of about 2.5 dB was pointed out between CSK-Himage and Ping-Pong images on agricultural fields. These results, achieved on bare soils, have also been compared with simulations performed by using the Advanced Integral Equation Model (AIEM). OPEN ACCESSRemote Sens. 2013, 5 2929

HydroCosmo: The Monitoring of Hydrological Parameters on Agricultural Areas by using Cosmo-SkyMed Images

“…Since data have been collected in two different CSK image modes (i.e. Himage and PingPong), the σ°H H values have been corrected according to the specific differences found between these two modes [Pettinato et al, 2013b]. It can be noted that the two clusters are rather close and both show appreciable determination coefficients, although with different SMC ranges due to the season of acquisition.…”

Potential of X-Band Images from High-Resolution Satellite SAR Sensors to Assess Growth and Yield in Paddy Rice

“…Recent studies using CSK and TSX have suggested certain relationships with vegetation parameters and soil moisture [28][29][30][31][32][33][34][35], but consistent and accurate relationships are not established. In addition, some discrepancies have been recognized between σ 0 values from CKS and TSX, e.g., [36,37].…”

“…Pettinato et al [37] suggested that CSK data would be corrected against TSX (Stripmap mode) by adding about 4 dB in Ping Pong mode and about 2.5 dB in Himage mode, respectively. They also suggested that these values may vary with measurement configurations, i.e., mode, orbit, polarization, and incidence angle.…”

Potential of X-Band TerraSAR-X and COSMO-SkyMed SAR Data for the Assessment of Physical Soil Parameters

“…Although they observed a temporally stable signal for each of the studied X-band sensors (TSX, CSK1, CSK2, CSK3, CSK4), significant differences reaching approximately 3 dB in the HH polarization and 5 dB in the HV polarization were found in the absolute signal levels measured by these sensors. The results of the comparative analysis established by Pettinato et al [39] have also demonstrated strong differences, equivalent to 4.8 dB, between the signals measured by TSX and CSK2. In the present study, TSX and CSK measurements are compared and analyzed using a large number of targets.…”

“…In the last two years, several studies making use of TSX and CSK data have revealed the need to inter-calibrate the raw measurement data [38,39], before it is applied to parametric analysis of the soil. Recently, Baghdadi et al [38] compared TSX and CSK signal levels recorded over forests.…”