The overall accuracy of digital landcover products can often be improved through the use of fused imagery products generated by good cross-sensor resolution enhancement algorithms. This paper describes a process for f...
详细信息
ISBN:
(纸本)0819421391
The overall accuracy of digital landcover products can often be improved through the use of fused imagery products generated by good cross-sensor resolution enhancement algorithms. This paper describes a process for fusing medium resolution multi-spectral data, such as Landsat and SPOT, with National Aerial Photographic Program (NAPP) photographs. The NAPP has a goal of providing coverage of the 48 contiguous United States every 10 years at high spatial resolution [i.e., 2 meter ground resolving distance (GRD)]. NAPP and National High Altitude Photography (NHAP) provide a wealth of current and historic high resolution data for environmental and natural resource studies. Despite their comprehensive coverage and high spatial resolution, these images are often overlooked for use in large-scale computerized classification problems, because: (1) they are photographic 'analog' data stored on film, not digital data on magnetic media; (2) comprehensive support data (e.g., aircraft x, y, z, roll, pitch, and yaw) is lacking; (3) they are not geocoded or orthorectified and random aircraft motion combined with sensor projection make it difficult to georegister; and (4) their radiometric quality varies both within and between images. This paper describes a technique for merging NAPP/NHAP data with lower resolution satellite data such as Landsat and SPOT which results in a fused image product that has the high spatial resolution of the NAPP/NHAP data and the spectral quality of the satellite data. The technique permits the user to utilize this higher resolution data to improve the quality and accuracy of their landcover, change detection, stress analysis, or other remote sensing products. Specific published results show an improvement in the overall accuracy from 79.4% correct classification using Landsat TM (25 meter GSD) alone to over 94.2% correct classification using higher resolution (5 meter GSD) data. We also discuss our future plans related to these techniques and their a
Future multispectral and hyperspectral remote sensing systems and image archives will benefit from effective, high-fidelity image compression techniques. in evaluating the effects of compression upon the data, one mus...
详细信息
ISBN:
(纸本)0819423645
Future multispectral and hyperspectral remote sensing systems and image archives will benefit from effective, high-fidelity image compression techniques. in evaluating the effects of compression upon the data, one must not only consider the qualitative and quantitative effects upon the images themselves, but also upon the end user products that are derived from the imagery through the application of environmental retrieval algorithms. At The Aerospace Corporation, we have developed a fast algorithm for image compression techniques known as the Modulated Lapped Transform (MLT). This compression algorithm obviates many of the artifacts that are introduced by some of the standard compression techniques. One example of compression artifacting is the blocking errors from Discrete Cosine Transformation (DCT) based algorithms, which include the JPEG compression scheme. The Aerospace MLT technique is a hybrid of the wavelet and DCT techniques. It employs our patented split-radix approach, which is the fastest DCT algorithm known today. In this paper, we compare Aerospace MLT to JPEG, using cloud imagery and Earth surface scene classification, We also discuss the availability of a cost-effective VLSI hardware implementation of the Aerospace compression algorithm. The Modulated Lapped Transform employs a peano scan with a split-radix approach to avoid blockiness artifacts. It has excellent resistance to errors, and it is amenable to fast processing using a 1-D hardware architecture to process a 2-D image. This technique encapsulates the favorable aspects of the wavelet transforms and produces images which, when compressed 10:1 and decompressed, compare very favorably (using error statistics, classification accuracy and visual quality metrics) to the original uncompressed image.
As a precursor to hardware implementation, we have performed mine detection functions in simulation on a polarimetric hyperspectral imaging (PHI) dataset collected by using a technique of acousto-optic tunable filter ...
详细信息
ISBN:
(纸本)0819418528
As a precursor to hardware implementation, we have performed mine detection functions in simulation on a polarimetric hyperspectral imaging (PHI) dataset collected by using a technique of acousto-optic tunable filter (AOTF) camera. In principle, PHI data of an image containing objects of interest in a cluttered background provide significant information about the objects, including their relative sizes, shapes, orientation, and other characteristics such as light reflectance and polarization signatures based on their material properties. The present study was, however, limited only to the direct spectral data for the object of interest. A feedforward artifical neural network (ANN) architecture was programmed to recognize predefined spectral 'templates' by using a well-known, hardware implementable inner-product matching scheme. This scheme is particulartly suited to the problem of spectral discrimination where the spectra to be examined or the objects to be discriminated are uncorrelated, as in the present case. In this paper, we describe the ANN architecture and discuss its hardware implementation issues. In addition, we provide the results of our simulation study performed along with suitable preprocessing steps with various window sizes from 1 X 1 to 50 X 50 pixels, leading to an unambiguous detection of the position of mines in test runs without false alarms.
Image analysis is especially laborintensive in the multispectral domain due to the non-intuitive nature of the data. The data is frequently separated by frequency range into a set of image planes. For image analysts (...
详细信息
This paper reports results from an analysis of polarimetric hyperspectralimagery collected using a prototype acousto-optic tunable filter (AOTF) instrument in an outdoor environment. Spectra, derivative spectra, and ...
详细信息
In this paper we present a new method for the extraction of information about Lines of Communication (LOC) from Landsat Thematic Mapper (TM) imagery. While other techniques have demonstrated some success in the extrac...
详细信息
A combination of towed and stationary shipboard measurements, bio-optical mooring data, and a series of AVIRIS images were acquired near an offshore sewage outfall which services the Los Angeles metropolitan area. The...
详细信息
ISBN:
(纸本)0819415359
A combination of towed and stationary shipboard measurements, bio-optical mooring data, and a series of AVIRIS images were acquired near an offshore sewage outfall which services the Los Angeles metropolitan area. The image containing the outfalls and in-situ measurements was examined using statistical techniques to derive the spectral components responsible for salient variations. These computed components agree quite well with spectra which were hand selected to qualitatively represent the scene. Suspended sediment and aquatic vegetation detection were investigated using spectral derivative techniques, which were quite successful in showing the extent of offshore kelp forests and storm-induced resuspension of previously deposited outfall effluent, or the effluent itself. The in-situ and remote sensing measurements were used to constrain a numerical model of the underwater light field, and the scattering properties along a surface transect were investigated using two phase functions. Using a one-term Henyey-Greenstein function with a backscattering ratio of nearly 30%, we were able to reproduce the remotely- sensed radiance, suggesting that the particulates had a size distribution skewed toward small. These investigations show the utility of high spectral resolution in determining the extent and character of several important natural and anthropogenic components of coastal areas, as well as parameterizing models of the inherent optical properties of the underwater light field.
暂无评论