An Efficient Algorithm for Inversion of Truncated Spiral Cone Beam Data

The University Of Central Florida Board Of Trustees, Orlando FL

Investigators

Abstract

A new approach for Fourier transform spectrometry (FTS) is proposed. The principal advantage of FTS is the tremendous throughput improvement compared to dispersive or filter spectrometers. Traditional FTS techniques, however, require a precision scanning mirror. This requirement significantly increases the cost, and is difficult to implement for use from a moving platform or for a dynamic target. A more recent technique does not require scanning. This provides the ability to acquire all spectral bands simultaneously, allows high spatial resolution from a moving platform, improves the reliability, and lowers the mass, volume and cost. These non-scanning FTS, however, have yet been unable to exploit the tremendous potential throughput advantage of FTS, since they require operation in a "pushbroom" mode. In this mode, a narrow slit masks the field-of-view (FOV) to a narrow strip and this severely reduces the throughput. The proposed approach uses deconvolution techniques to provide spatial resolution along-track, without the need for a narrow field mask. This technique can therefore simultaneously provide both the throughput advantage of traditional FTS, and all the advantages of non-scanning FTS. Imaging spectrometry is a powerful tool for Earth Science, particularly for investigation of land cover and land use change. When applied to Space Science, particularly exploration of the solar system, imaging spectrometry is the primary tool for global determination of surface mineralogy and is also useful for studies of atmospheric composition. In Human Exploration and Development of Space, spectrometry is being employed for diagnostics of reusable rocket engines, by observation of the exhaust plume. The proposed technique provides a factor of 10 to 1000 advantage in throughput compared to current techniques for imaging spectrometry, allowing greatly improved radiometric resolution. The absence of moving parts improves the reliability and lowers the cost, mass and power requirements.