초록 ▼

A method and apparatus determines the shape of an orbiting or airborne object. A radar determines the general location and a telescope is directed toward the object to form an image of background stars, which will be occluded by the object. The image is compared with a memorized star map, to identif

A method and apparatus determines the shape of an orbiting or airborne object. A radar determines the general location and a telescope is directed toward the object to form an image of background stars, which will be occluded by the object. The image is compared with a memorized star map, to identify the region of the image in the map. Stars visible in the map which are not visible in the image are listed. The invisible stars are paired with next adjacent visible stars to form star pairs. The midpoints are identified of lines extending between star pairs. Segment lines are drawn between a midpoint and the next closest midpoint. The segment lines define an outline of the object.

대표청구항 ▼

What is claimed is: 1. A method for determining the shape of an object in an Earth orbit, said method comprising the steps of: operating a radar system to determine the range, azimuth and elevation of the object relative to the radar; deploying an optical telescope at a location at which it is capa

What is claimed is: 1. A method for determining the shape of an object in an Earth orbit, said method comprising the steps of: operating a radar system to determine the range, azimuth and elevation of the object relative to the radar; deploying an optical telescope at a location at which it is capable of viewing the region in which said object is located and which has a known relationship to the location of the radar; pointing said optical telescope toward said object, thereby producing an image of background stellar objects in an angular field of view encompassing said object; providing a memorized representation of at least some of the stellar objects in said angular field of view; comparing said image of background stellar objects with said memorized representation of the stellar objects as they would be expected in an unocculted field of view, to thereby identify some of those stellar objects which are occulted by said object; and using a computer processor, determining an outline of the object from said occulted and unocculted stellar objects. 2. A method according to claim 1, further comprising the steps of: repeating said steps of pointing said optical telescope toward said object; comparing said image of background stellar objects with said memorized representation; and using a computer processor, determining from said occulted and unocculted fields of view an outline of the object, thereby generating a time sequence of images of said object, which reveals any changes in projected shape of said object. 3. A method according to claim 1, further comprising the step of displaying on a monitor an image of the outline of said object. 4. A method according to claim 3, wherein said step of displaying on a monitor includes the step of displaying on a video monitor. 5. A method according to claim 1, wherein said step of pointing said optical telescope toward said object thereby producing an image of background stellar objects in an angular field of view encompassing said object comprises the steps of: determining the location of said radar; determining the location of said telescope; determining from said location of said radar and of said telescope the direction of said object from said telescope; pointing said telescope in said direction to view said object; and operating said telescope to produce data representing an image of said object. 6. A method according to claim 1, wherein said step of comparing said image of background stellar objects with a memorized representation of the stellar objects as they would be expected in an unocculted field of view, to thereby identify those stellar objects which are occulted by said object includes the steps of: obtaining coordinates and brightness of at least some of the stellar objects in the field of view (412); determining that portion of said memorized representation of the stellar objects which corresponds to said field of view; performing least-squares optimization of apparent locations of stellar objects in said portion of said memorized representation and in said image in said field of view, to thereby align said image with said portion of said memorized representation; and listing the locations of stellar objects in said portion of said memorized representation which are missing from said image. 7. A method according to claim 6, wherein said step of performing least-squares optimization includes the step of obtaining coordinates and brightness of at least some of the stellar objects in said memorized representation in said portion. 8. A method according to claim 6, wherein said step of determining from said occulted and unocculted fields of view an outline of the object comprises the steps of: finding that one of the visible stellar objects in the image which is closest to one of said stellar objects missing from said image; pairing each of said stellar objects which is missing from said image with said closest one of said visible stellar objects, to thereby form stellar object pairs; disregarding those said object pairs that are not among the most nearly co-located of said stellar object pairs; generating a stellar object pair line for each of said stellar object pairs, said stellar object pair line extending from the location of the missing one of said pair of stellar objects to the visible one of said pair of stellar objects; determining the midpoint of each of said stellar object pair lines; connecting the midpoint of one of said stellar object pair lines by an outline segment to the midpoint of the next adjacent one of said stellar object pair lines; repeating said step of connecting the midpoint until all of said midpoints are connected by outline segments to adjacent ones of said midpoints; and displaying an image of said outline segments. 9. An apparatus for determining the shape of an elevated object, said apparatus comprising: a radar system at a known location, for using electromagnetic radiation to determine the pointing azimuth and elevation of said elevated object; a telescope at a known location relative to the location of said radar system, said telescope being directed toward said elevated object for generating an image of said object occulting a field of background stellar objects; a memorized map of the locations and brightness of at least some stellar objects in a region including at least part of said image; a display for displaying an outline of said elevated object; and a processor for comparing said map with said image, for correlating said map with said image, and for identifying relevant stellar objects which are found in said map but missing from said image, and for generating from said missing and present stellar objects said outline of said object. 10. A method for determining the shape of an object in an Earth orbit which includes periods of time in which the object is in Earth's umbra, said method comprising the steps of: radar tracking of said object in order to determine its approximate ephemera including range, altitude, apogee, axis of orbit and phase of the orbit and location; deploying a radar system in a location capable of viewing the object, and operating the radar to determine the range, azimuth and elevation of the object relative to the radar; deploying an optical telescope at a location at which it is capable of viewing the region in which said object is located and which has a known relationship to the location of the radar; pointing said optical telescope toward said object, thereby producing an image of background stellar objects in an angular field of view encompassing said object; comparing said image of background stellar objects with a memorized representation of the stellar objects as they would be expected in an unocculted field of view, to thereby identify those stellar objects which are occulted by said object; and using a computer processor, determining an outline of the object from said occulted and unocculted stellar objects.