Hexagonal sampling and filtering for target detection with a scanning EO sensor
Abstract
Current sensor systems use a rectangular or square sampling lattice. For a circular blur function, a hexagonal sampling lattice is more efficient than a rectangular lattice. For example, for signal reconstruction it has been proven that hexagonal sampling is the most efficient lattice, i.e., the lattice with the minimum number of sample points to achieve an exact reproduction of a circular wavenumberlimited function. A simple, practical method for generating a hexagonal sampling lattice is described for an EO scanning sensor. Matched filtering techniques are developed for hexagonally sampled data. An efficient approximate matched filter is described which uses integer weights and takes advantage of the structure of the data. Relative to this filter, the number of processing operations increases for a rectangular sampling lattice, by a factor of six for an ideal matched filter and by 25% for an approximate filter with integer weights.
 Publication:

Signal and Data Processing of Small Targets 1991
 Pub Date:
 August 1991
 DOI:
 10.1117/12.45676
 Bibcode:
 1991SPIE.1481....2S
 Keywords:

 Data Sampling;
 Optoelectronic Devices;
 Signal Processing;
 Target Acquisition;
 Lattices (Mathematics);
 Matched Filters;
 Scanners;
 Spacecraft Instruments;
 Instrumentation and Photography