On the Correction of Partial Beam Blockage in Polarimetric Radar Data
نویسندگان
چکیده
Three methodologies for correcting the radar reflectivity factor (ZH) in the presence of partial beam blockage are implemented, compared, and evaluated using a polarimetric radar dataset from the North American Monsoon Experiment (NAME) in northwestern Mexico. One methodology uses simulated interactions between radar beams and digital terrain maps, while the other two invoke the self-consistency of polarimetric radar measurands in rainfall, and the relative insensitivity of a specific differential phase to beam blockage. While the different methodologies often agree to within 1–2 dB, significant disagreements can occur in regions of sharp azimuthal gradients in beam blockage patterns, and in areas where the terrain-caused radar clutter map is complex. These disagreements may be mitigated by the use of additional radar data to develop the polarimetric correction techniques, by a more sophisticated terrain-beam interaction model, or by a higherresolution digital terrain map. Intercomparisons between ground radar data and Tropical Rainfall Measuring Mission satellite overpasses suggest that all of the methodologies can correct mean ZH to within the expected uncertainty of such intercomparisons (1–1.5 dB). The polarimetric correction methods showed good results even in severely blocked regions (.10 dB reduction). The results suggest the possibility that all of the techniques may be valid approaches to correcting partial beam blockage, and within that context relative advantages and disadvantages of each technique are discussed. However, none of the techniques can correct radar data when weak echoes are reduced to noise by strong blocks, thus leading to biases in corrected ZH and rainfall climatologies.
منابع مشابه
Three-stage inversion improvement for forest height estimation using dual-PolInSAR data
This paper addresses an algorithm for forest height estimation using single frequency single baseline dual polarization radar interferometry data. The proposed method is based on a physical two layer volume over ground model and is represented using polarimetric synthetic aperture radar interferometry (PolInSAR) technique. The presented algorithm provides the opportunity to take advantages of t...
متن کاملERAD 2012 - THE SEVENTH EUROPEAN CONFERENCE ON RADAR IN METEOROLOGY AND HYDROLOGY Design and test of an X-band optimal rain rate estimator in the frame of the RHYTMME Project
The RHYTMME project (Risques HYdro-météorologiques en Territoires de Montagnes et MEditerranéens) was developed in order to establish a platform of services allowing a better management of hydrometeorological risks in the French southern Alps, which are prone to intense precipitation events and flash floods. In the frame of the RHYTMME Project, Météo France is deploying a dense network of 4 pol...
متن کاملImprovement of Biomass Estimation in Forest Areas based on Polarimetric Parameters Optimization of SETHI airborne Data using Particle Swarm Optimization Method
Estimation of forest biomass has received much attention in recent decades. Airborne and spaceborne (SAR) have a great potential to quantify biomass and structural diversity because of its penetration capability. Polarizations are important elements in SAR systems due to sensitivity of them to backscattering mechanisms and can be useful to estimate biomass. Full Polarimetric Synthetic Aperture ...
متن کاملClassification of polarimetric radar images based on SVM and BGSA
Classification of land cover is one of the most important applications of radar polarimetry images. The purpose of image classification is to classify image pixels into different classes based on vector properties of the extractor. Radar imaging systems provide useful information about ground cover by using a wide range of electromagnetic waves to image the Earthchr('39')s surface. The purpose ...
متن کامل