recentdevelopments in reconstruction and resolution enhancement for microwave instruments suggest a possible tradeoff between computation, resolution, and downlink data rate based on postcollection reconstruction/ re...
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recentdevelopments in reconstruction and resolution enhancement for microwave instruments suggest a possible tradeoff between computation, resolution, and downlink data rate based on postcollection reconstruction/ resolution enhancement processing. The Hydrospheric State mission is designed to measure global soil moisture and freeze/thaw state in support of weather and climate prediction, water, energy, and carbon cycle studies, and natural hazards monitoring. It will use an active and passive L-band microwave system that optimizes measurement accuracy, spatial resolution, and coverage. The active channels use synthetic aperture radar-type processing to achieve fine spatial resolution, requiring a relatively high downlink data rate and ground processor complexity. To support real-time applications and processing, an optional postcollection reconstruction and resolution enhancement method is investigated. With this option, much lower rate real-aperture radar data are used along with ground-based postprocessing algorithms to enhance the resolution of the observations to achieve the desired 10-km resolution. Several approaches are investigated in this paper. It is determined that a reconstruction/resolution enhancement technique combining both forward- and aft-looking measurements enables estimation of 10-km resolution or better backscatter values at acceptable accuracy. Key tradeoffs to achieve this goal are considered.
Incomplete image data sets are of interest in many domains and arise in a variety of applications, and in particular in applications that use remote sensor array data. Although recentdevelopments in mesh modelling of...
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Incomplete image data sets are of interest in many domains and arise in a variety of applications, and in particular in applications that use remote sensor array data. Although recentdevelopments in mesh modelling of images have provided algorithms that can achieve accurate and efficient image representations without the high computational cost associated with earlier optimisation-based methods, such techniques rely on the availability of the entire image data. These content-based mesh modelling techniques aim to provide a high sample density in regions of interest, such as feature neighbourhoods or around moving objects, whilst achieving efficiency by retaining a low overall image sampling density. The sampling density is determined by a feature map, such as local image curvature or local spatial-frequency content that is obtained from the underlying complete image data. As the requirement for the availability of complete image data makes such content-based mesh modelling techniques unsuitable for application to incomplete images, where an image consists of a sparse data set, we aim to address this issue by proposing an alternative approach to mesh modelling that is based on automatically adaptive feature detection directly applicable to sparsely sampled images.
recentdevelopments in pulsed Doppler lidar technology for range-resolved aerosol and hard-target imaging applications are presented. Systems based upon CO2 and fiber-optic technologies at wavelengths of 10.6mum and 1...
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ISBN:
(纸本)0819455733
recentdevelopments in pulsed Doppler lidar technology for range-resolved aerosol and hard-target imaging applications are presented. Systems based upon CO2 and fiber-optic technologies at wavelengths of 10.6mum and 1.5mum respectively are described. Data are presented showing aspects of system and component development as well as recent field deployments.
This paper reviews general methodologies for hyper-spectra imageprocessing and provides a systematic way of hyperspectra data exploitation. Although the paper reviews the most recent hyperspectra processing technique...
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This paper reviews general methodologies for hyper-spectra imageprocessing and provides a systematic way of hyperspectra data exploitation. Although the paper reviews the most recent hyperspectra processing techniques, which are available in the open literature, it focusses on those that have been recently developed by the authors. These approaches often complement work presented by others. Since the field of hyperspectra processing is relatively new, and is growing rapidly, it is a field rich of research areas with many unsolved problems. Its significance in military, and more generally in remotesensingapplications, is tremendous. Furthermore, this paper has the objective to offer a quick look to the many approaches, to put in light the authors' recentdevelopments in this field, and to serve as a background for new advances.
While most recent work on synthetic aperture radar (SAR) image segmentation has concentrated on accurately segmenting single channel images, many SAR applications involve multi-channel analysis. Hence, if segmentation...
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While most recent work on synthetic aperture radar (SAR) image segmentation has concentrated on accurately segmenting single channel images, many SAR applications involve multi-channel analysis. Hence, if segmentation algorithms are going to be of real use, they must be applicable to multi-channel images. The aim multi-channel segmentation is to produce a single region labeling from the multi-channel input. Each segment should represent a homogeneous region that differs statistically from each adjacent segment. Segment boundary maps may be used to investigate structural change in multi-temporal imagery. Alternatively, the multi-channel image may be classified based on parameters estimated within segments, guaranteeing that parameters are estimated over the largest available homogeneous regions.
Low Earth orbit provides an ideal operating environment for synthetic aperture radar (SAR) imaging due to well-defined platform motion. Airborne SAR platforms do not benefit from this luxury and suffer unpredictable m...
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Low Earth orbit provides an ideal operating environment for synthetic aperture radar (SAR) imaging due to well-defined platform motion. Airborne SAR platforms do not benefit from this luxury and suffer unpredictable motions causing image defocusing. Autofocus is a widely acknowledged technique for correcting these motions, causing the image to be properly focused. Accurate position and velocity information is required to process spaceborne SAR scenes with higher spatial resolutions requiring greater knowledge of the satellite's orbit. The availability of position and velocity data is dependant on the efficiency and location of the ground station and could finally lead to delays in processing times. In these cases an orbital propagation model has to be employed for immediate processing. The precision of the image is now dependent on the accuracy of the orbit model used. Using DRA patented autofocus/phase correction techniques on ERS1 raw data it is shown that the point target response of imagery obtained with no prior orbit knowledge is comparable with precision imagery. In addition the technique allows continuous strip map imagery to be produced with no discontinuities.
Since the launch of its first pre-operational model, the Meteosat system has evolved as one of the most well-known Earth observation satellite projects. In particular through its imagery mission it has become an indis...
Since the launch of its first pre-operational model, the Meteosat system has evolved as one of the most well-known Earth observation satellite projects. In particular through its imagery mission it has become an indispensable tool for a large user community. Both the quality of the images produced by Meteosat satellites and their processing onground have been continuously improved in recent years. This paper is a short review of the present capabilities and applications of the Meteosat imageprocessing at the European Space Operations Centre (ESOC, Darmstadt). It starts with a brief overview on available hardware tools for real-time and offline processing of Meteosat images. Geometrical image restoration and radiometric quality control are the main tasks in this area. But in addition a number of dedicated (software) tools and test set-ups had to be developed for special testing of the satellite performance, for instance during the commissioning of a new spacecraft. Finally, a short summary on current studies and new developments related to the Meteosat imagery mission concludes this review.
The proceedings contains 7 papers. Some of the specific topics discussed are: detection of unusual events in remote sensed imagery;detection of typical image features;subsea image interpretation - a problem in remote ...
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The proceedings contains 7 papers. Some of the specific topics discussed are: detection of unusual events in remote sensed imagery;detection of typical image features;subsea image interpretation - a problem in remotesensing;and a design procedure for the design of advanced coded pulse radar waveforms generated from a finite set of samples.
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