Spectral imagery in the far ultraviolet: Results from a sounding rocket experiment

We describe a new technique of space based spectral imagery from a spinning platform. The technique uses tomographic inversion to produce a two-dimensional spectral image using a novel imaging spectrograph. The spectrograph uses a single optical element (a diffraction grating) with a large field of view (100 x 100).Our technique delivers high throughput due to continuous observation of the scene at all wavelengths. The challenge of spectral imaging is to obtain 3-dimensional information (two dimensions for image and the third for spectrum) from a time series of two-dimensional data. In our technique, we obtain spectral information along one detector dimension, while two dimensions of spatial information are combined into the second dimension of the detector for each time step. With the spin axis of the spacecraft located at the center of the scene, we recover the two dimensions of spatial information from a series of these individual snapshots. We will report on the results obtained on May 8, 1997 by a sounding rocket experiment using this technique in the 80 -l4Onm wavelength range, on the Scorpio constellation.