Optimal focal-plane restoration

Image restoration can be implemented efficiently by calculating the convolution of the digital image and a small kernel during image acquisition. Processing the image in the focal-plane in this way requires less computation than traditional Fourier-transform-based techniques such as the Wiener filter and constrained least-squares filter. Here, the values of the convolution kernel that yield the restoration with minimum expected mean-square error are determined using a frequency analysis of the end-to-end imaging system. This development accounts for constraints on the size and shape of the spatial kernel and all the components of the imaging system. Simulation results indicate the technique is effective and efficient

Software for the Standard Linear Format for Digital Cartographic Feature Data

This paper describes application software and programming tools designed for use with the Defense Mapping Agency\u27s (DMA) Standard Linear Format (SLF) for Digital Cartographic Feature Data. The Standard Linear Format (SLF) is briefly described in this report. It was designed as a standard for the exchange of digital cartographic features on magnetic tape. The format specifies descriptive fields about feature data, as well as specifying the representation of the features. The application software described in this report can transfer files or tapes in this format to relational database maintained under Ingres, graph features in the database, alter the database, and convert the database back to the SLF. The subroutine library utilized by these application programs is also described. These subroutine should make the task of writing additional application software for the SLF much easier

Information efficiency in hyperspectral imaging systems

In this work we develop a method for assessing the information density and efficiency of hyperspectral imaging systems that have spectral bands of non-uniform width. Imaging system designs with spectral bands of nonuniform width can efficiently gather information about a scene by allocating bandwidth among the bands according to their information content. The information efficiency is the ratio of information density to data density and is a function of the scene’s spectral radiance, hyperspectral system design, and signal-to-noise ratio. The assessment can be used to produce an efficient system design. For example, one approach to determining the number and width of the spectral bands for an information- efficient design is, to begin with a design that has a single band and then to iteratively divide a band into two bands until no further division improves the system’s efficiency. Two experiments illustrate this approach, one using a simple mathematical model for the scene spectral-radiance autocorrelation function and the other using the deterministic spectral-radiance autocorrelation function of a hyperspectral image from NASA’s Advanced Solid-State Array Spectroradiometer. The approach could be used either to determine a fixed system design or to dynamically control a system with variable-width spectral bands (e.g., using on-board processing in a satellite system)