A SAR geocoding method for evaluating geodetic coordinates and improving indirect geocoding accuracy

Karathanassi, V; Iossifidis, Ch

dc.contributor.author	Karathanassi, V	en
dc.contributor.author	Iossifidis, Ch	en
dc.date.accessioned	2014-03-01T02:49:12Z
dc.date.available	2014-03-01T02:49:12Z
dc.date.issued	2002	en
dc.identifier.issn	0277786X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34402
dc.subject	Accuracy	en
dc.subject	Direct geocoding	en
dc.subject	Geodetic coordinates	en
dc.subject	Indirect geocoding	en
dc.subject	SAR	en
dc.subject.other	Algorithms	en
dc.subject.other	Calculations	en
dc.subject.other	Computational methods	en
dc.subject.other	Estimation	en
dc.subject.other	Geodetic satellites	en
dc.subject.other	Global positioning system	en
dc.subject.other	Image quality	en
dc.subject.other	Iterative methods	en
dc.subject.other	Synthetic aperture radar	en
dc.subject.other	Direct geocoding method	en
dc.subject.other	Geocoding method	en
dc.subject.other	Geodetic coordinates	en
dc.subject.other	Indirect geocoding process	en
dc.subject.other	Radar imaging	en
dc.title	A SAR geocoding method for evaluating geodetic coordinates and improving indirect geocoding accuracy	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1117/12.463243	en
heal.identifier.secondary	http://dx.doi.org/10.1117/12.463243	en
heal.publicationDate	2002	en
heal.abstract	In Synthetic Aperture Radar (SAR) images, direct geocoding accuracy is affected by the accuracy of the input parameters, such as orbit data, initial height values introduced in the ellipsoid equation, and approximate values of the geodetic coordinates. Specifically, the approximate geodetic coordinates, required for even pixel in the image by direct geocoding. contain errors mainly due to pixel misidentificalions on the map. to topographic maps. DEM and gravimetric to orthometric model. This paper describes a method, which evaluates the accuracy of the approximate geodetic coordinates introduced in the direct geocoding method for any pixel in the image, without the 'true' geodetic values being known. The method is based on the 'pseudo-errors' produced by the subtraction of the calculated by the direct geocoding method coordinates, from the approximate input coordinates introduced in the method. Tests and evaluation of the above method are performed using three test points and the known coordinates of four reflectors. It is shown that for the pixels of the SAR image, the corresponding evaluated geodetic coordinates when introduced as control points in the indirect geocoding process may produce geocoding results of accuracy higher than 1.4 ERS pixels. The developed method is useful if no reflector is located in the study area, because it produces four times belter accuracies, compared to those usually produced by indirect geocoding.	en
heal.journalName	Proceedings of SPIE - The International Society for Optical Engineering	en
dc.identifier.doi	10.1117/12.463243	en
dc.identifier.volume	4886	en
dc.identifier.spage	268	en
dc.identifier.epage	278	en