Stereoscopic Geometry of the Remote Sensing 'Optical Mapping Instrument'.

摘要

This Report examines the geometrical principles of stereoscopic remote sensing upon which the proposed Optical Mapping Instrument system is based. Consideration is given to the cartographic potential of the system in terms of constraints that arise from the viewing geometry, and conclusions are reached concerning the required accuracy and stability of the instrument. The proposed Optical Mapping Instrument (OMI) is a space-based remote-sensing payload designed to produce high-resolution image data from which cartographic information can be derived. An outline specification of the OMI is given in Appendix A. The instrument has the capability of generating a stereoscopic pair of images of a given region, taken from different positions in a sun-synchronous, near-polar orbit. Northings and Eastings (or planimetric data) can be inferred from a single image, however the relative height of the terrain (or topographic data) is only derivable from a stereoscopic pair of images of the desired region. As examined in the present report, the parallax, ie the apparent relative displacement of features in the two images that results from a change in viewing position, is used to calculate the relative height of any point in the scene. The main purpose of the report is therefore to study the geometry associated with this stereo-viewing technique. The geometry has a direct bearing on the cartographic potential of the system since the desired system performance is governed by requirements arising from various geometrical constraints. Section 3 of this Report introduces the relationship between mapping potential and viewing geometry. Keywords: Great Britain. (KR)