Practical SAR orthorectification

Pierce, L.E.; Kellndorfer, Josef; Ulaby, F. T.; Norikane, L.

doi:10.1109/igarss.1996.516977

Cited by 11 publications

(2 citation statements)

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“…63 Range-Doppler terrain correction was applied to all SAR images to compensate for topographically induced geometric distortions. 64 Backscatter data were converted to the dB scale for better contrasts in the low-value ranges. SSM/I products were directly used as provided by the NSIDC due to their extensive and accurate internal calibration.…”

Section: Data Preparationmentioning

confidence: 99%

Above-ground biomass estimates based on active and passive microwave sensor imagery in low-biomass savanna ecosystems

Braun

Wagner

Hochschild

2018

J. Appl. Rem. Sens.

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Although many studies exist on the estimation and monitoring of above-ground biomass (AGB) of forest ecosystems by methods of remote sensing, very little research has been carried out for ecosystems of low primary production, such as grasslands, steppes, or savannas. Our study intends to approach this gap and investigates the correlation between space-borne radar information and AGB at the scale of 10 tons per hectare and below. Additionally, we introduce the integration of passive brightness temperature as an additional covariate for biomass estimation, based on the hypothesis that it contains information complementary to microwave backscatter of the active sensors. Our findings show that large-scale estimates of AGB can be conducted for grasslands and savannas at high accuracy (R 2 up to 0.52). Additionally, we found that the integration of passive radar can increase the quality of AGB estimates in terms of explained variance for selected cases. We hope that these indications are a starting point for more integrated approaches toward biomass estimations based on Earth observation methods.

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Section: Data Preparationmentioning

confidence: 99%

Above-ground biomass estimates based on active and passive microwave sensor imagery in low-biomass savanna ecosystems

Braun

Wagner

Hochschild

2018

J. Appl. Rem. Sens.

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“…Product header contains accurate information related to the above values for a reduced (but significant) number of pixels in the image, called tie points. Values corresponding to other pixels are estimated via Delaunay triangulation [29]; 2. given the geographical coordinates lat i,j and long i,j , elevation information h i,j is derived from the available DEM with a bi-linear interpolation; 3. compute x ortho (i, j) as follows:…”

Section: Orthorectificationmentioning

confidence: 99%

Near real-time SAR-based processing to support flood monitoring

Cossu

Schöepfer

Bally

et al. 2009

J Real-Time Image Proc

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Earth Observation has proven to be a synoptic and objective source of information to derive crisis and damage maps. In case of flood events, often characterized by weather conditions which prevent the possibility of exploiting data acquired by optical sensors, synthetic aperture radar (SAR) sensors become the only space-born source of information due to their all-weather capability. In order to assure the delivery of damage maps as soon as possible after a disaster, the access and the exploitation of SAR data must be accelerated and simplified with respect to the current procedures. In this context, two issues needed to be addressed: fast access to large data archives, and provision of near real-time on demand processing services. This paper presents a near real-time SAR processing service to support the mapping of flooded areas. The service exploits Grid technology to manage large volumes of data and to provide the computational resources to cope with SAR processing demanding tasks. The algorithm for the implemented orthorectification of the final products is presented. The validation of the derived products shows a reliable accuracy for co-registration of half a pixel. The geolocation accuracy resulted below 100 m. The service makes a significant contribution to accelerating the access and exploitation of ESA SAR data.

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