This paper presents a technique to detect oil spills in ENVISAT Advanced Synthetic Aperture Radar (ASAR) images using radar backscatter thresholding and logistic regression analysis. We developed and tested this technique using 4 Envisat ASAR images that were acquired many days after the M/T Solar I oil spill incident occurred on August 11, 2006 in Panay Gulf, southwest of Guimaras Island in Vi...

High precision DEM of a tidal-flat is valuable to coastal management as well as pure scientific interest including erosion and sedimentation rate study. Geomorphologic mapping in coastal zone is, however, complicated by the rapid and significant changes on many fluvial forms and poor topographic expression of the landform. Three space-borne SAR systems including ALOS PALSAR, TerrrSAR-X and ERS-...

Radar altimetry is now commonly used for the monitoring of water levels in large river basins. In this study, an altimetry-based network of virtual stations was defined in the quasi ungauged Ogooué river basin, located in Gabon, Central Africa, using data from seven altimetry missions (Jason-2 and 3, ERS-2, ENVISAT, Cryosat-2, SARAL, Sentinel-3A) from 1995 to 2017. The performance of the five l...

SCIAMACHY onboard the environmental research satellite ENVISAT is a UV/visible/near-infrared grating spectrometer providing 3 near infrared channels covering wavelengths from 1-1.75μm, 1.94-2.04μm and 2.262.38μm with moderate spectral resolution (0.22-1.5nm) (Bovensmann et al. 1999). Among the absorbers in these regions are the greenhouse gases CO2, CH4, N2O and H2O as well as CO. A modified DO...

For over a decade, the Delft precise ERS-1 and ERS-2 orbits have been used in many scientific investigations based on ERS altimeter and interferometric SAR data. This orbit computation is now continued for Envisat, with an unprecedented accuracy due to better tracking data and lower force model errors. Orbit errors due to inaccuracies in the Earth’s gravity model, which have been the main focus...

The objective of this study is to demonstrate how polar ozone depletion can be mapped and quantified by assimilating ozone data from satellites into the wind driven transport model DIAMOND, (Dynamical Isentropic Assimilation Model for OdiN Data). By assimilating a large set of satellite data into a transport model, ozone fields can be built up that are less noisy than the individual satellite o...

We quantify the bias and uncertainty of interferometric synthetic aperture radar (InSAR) displacement time series and their derivatives, the displacement velocities, by analyzing the systematic and stochastic components of the temporal variation of the tropospheric delay. The biases due to the systematic seasonal delay depend on the SAR acquisition times, whereas the uncertainties depend on the...

S U M M A R Y Errors in the satellite orbits are considered to be a limitation for Interferometric Synthetic Aperture Radar (InSAR) time-series techniques to accurately measure long-wavelength (>50 km) ground displacements. Here we examine how orbital errors propagate into relative InSAR line-of-sight velocity fields and evaluate the contribution of orbital errors to the InSAR uncertainty. We e...