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The dual precipitation radar (DPR) on board the GPM (Global precipitation measurement) core observatory satellite is expected to improve our knowledge of precipitation processes. DPR offers dual frequency observations (Ku and Ka band) along the vertical profiles which allow us to investigate the microphysics using the difference between two frequency observations (measured dual frequency ratio or...
We develop the rain/no-rain classification (RNC) method for an over-land rainfall retrieval algorithm for the Advanced Microwave Sounding Unit (AMSU) based on the Global Satellite Mapping of Precipitation microwave radiometer algorithm. The current RNC method over land based on the window channel tends to underestimate warm rain areas due to high land surface emissivity. The sounder channels are less...
Dual wavelength precipitation radar (DPR) is planned to be deployed in the GPM core satellite. The DPR is expected to provide improved characterization of the raindrop size distribution ( DSD), as well as rainfall rate estimation from a combination of Ku band and Ka band radar measurement [1]. The Ku band radar is nearly same as the TRMM Precipitation radar. The Ka band provides higher sensitivity...
The JAXA-NASA Joint Algorithm Team has developed the Level 2 algorithm for Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) core observatory, which will be launched in 2014. Correction method for attenuation by cloud liquid water (CLW) is one of future issues in the DPR algorithm. Recently, a 3.5km-mesh global simulation has been performed using a Nonhydrostatic...
In our experience, as data from every deployment are processed and analyzed, new questions emerge. This implies that, even after decades of excellent work by many researchers, the use of high resolution thermal imaging to address the types of phenomena discussed here, and others, is still in fact at an early stage and will remain a fruitful field of study.
Active thermography is a non-contact instrumentation that can be used to investigate small-scale air-sea interaction processes at a footprint of a square meter and with time constants of minutes. It can be used also in large wind/wave facilities. Therefore it is a very useful instrument to investigate the mechanisms of air-sea gas transfer. The principles of the measurement technique are explained...
The fluid mechanics associated with the interface between two fluids, and in particular air and water, is of obvious importance in applications such as remote sensing, and the characterization of the environment. In remote sensing applications interfacial dynamics play a role in determining signatures in the radar, infrared, and visible wavelengths of the electromagnetic spectrum. These dynamics also...
Atmospheric correction of hyperspectral image data is frequently a requirement for using remote sensing to understand and quantify various phenomena that take place on the Earth. This is particularly true when the analysis requires the use of spectral reflectance. Although sophisticated models for atmospheric correction exist, evaluating the performance of these models is non-trivial. In this study,...
A simple method for optimization of kernel function and regularization parameters in the kernel MNF transformation is devised and applied to change detection in simple differences of bi-temporal DLR 3K camera system data. Figure 3 shows that although we get a much higher SNR for s = 1.7 than for s = 1.5 (57.40 dB vs 51.52 dB), the latter case because of the product applied, provides several (here...
Starting with a comparison of state of the art criteria and the influence of filtering, this paper presents an analysis tool for multi-temporal SAR images. It is based on the detection of a step change pattern with a generalized maximum likelihood ratio test. Compared to previous works on similar subject, the proposed approach takes into account a filtering step by a non-local approach and a spatially...
Nowadays, several optical space-borne systems with high resolution, high temporal revisit frequency and constant viewing angles are preparing to be be launched: Venµs, Sentinel-2, etc. The usefulness of these data will be limited due to for instance cloud coverage over the scene. Image fusion techniques with other satellite products of even higher revisit frequency will dramatically promote the usefulness...
Spaceborne radiometric measurements at L-band from the Aquarius instrument are compared to numerical model simulation. The empirical calibration of the data, performed over oceans only, is checked for consistency with measurements over the celestial sky. The calibration for the horizontal polarization is found to extend properly to the cold sky temperature, but the vertical polarization exhibit large...
The sea surface salinity (SSS) retrieved from the Soil Moisture and Ocean Salinity (SMOS) mission are systematically lower than ARGO SSS in rainy regions. These freshenings increase (in absolute value) with increasing SSM/I rain rates (−0.2psu/mm/hr) closely collocated in time with SMOS SSS. They are attributed to a stratification of the salinity in the first meters of the ocean surface following...
Focusing on the issue of echo data acquire approach in bistatic SAR system. In this paper, the key technology of echo sampling window synchronization is introduced, the effect of echo sampling window synchronization error to the echo data and image performance are analyzed, an adaptive echo sampling window synchronization approach based on amplitude demodulation and phase compare is proposed, which...
In this paper, a frequency domain imaging algorithm is proposed for the spaceborne/airborne bistatic synthetic aperture radar (SA-BSAR) with highly squint angle. The imaging processing is carried out with the following two stages. In the first stage, the space-invariant part of the raw spectrum data is compensated by multiplying with the conjugate of the spectrum from the reference target. In the...
This paper presents the algorithm to synthesize apertures using reflected GPS signal. In this concept, while GPS satellite is utilized as non-cooperative transmitter, receiving platform flies much closer to the Earth's surface and therefore there is an asymmetry in the geometry. Hence we refer to this geometry as quasi mono-static and by considering this asymmetry as well as the characteristics of...
Range cell migration correction (RCMC) is the key process in the imaging formation of the bistatic SAR. Due to the existence of double-square-root in the bistatic range equation, the RCMC in the general bistatic SAR configuration is more complicated than the traditional monostatic method. In this letter, the range cell migration of bistatic SAR system is analysed in detail, and a novel data transformation...
This work addresses the applicability of the Compressed Sensing theory to high resolution remote sensing imagery. After reviewing the concepts of the Compressed Sensing theory, we identified the key points where algorithmic choices had to be done to fulfill the constraints of image acquisition and onboard limited ressources: • Choosing a decomposition basis which is known to produce a sparse representation...
This paper focuses on quality assessment of fusion of multispectral (MS) images with high-resolution panchromatic (Pan) images. Since most existing quality assessments take the entire image into account simultaneously and generate some uncertainties, a novel and rather objective quality index has been proposed for image fusion. The index is comprised of geometric and radiometric parts. Both geometric...
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