US 6,480,270 B1Granted

Method for monitoring objects or an object area

AssigneeRiegl Laser Measurement Systems GmbH

InventorsNikolaus Studnicka, Andreas Ullrich

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Abstract

A laser-based target detection system applicable to search and rescue operations takes into account a plurality of optical attributes in the energy delivered to, and received from, a target-containing area. In addition to analyzing the returned optical signature for sufficient energy reflected by a potential target at a primary laser wavelength, the system also senses the target's effect on a supplemental optical attribute. Only when sufficient amplitude at the primary wavelength is detected in conjunction with a substantial effect on the supplemental optical attribute is a valid target confirmed. The supplemental optical attribute can be amplitude at a wavelength other than the primary wavelength, with the system looking for a high degree of attenuation at the non-primary wavelength, or polarization. with the system preferably looking for change of orientation in the return optical signature. The system includes scan head chassis (102) for transmitting energy to a target-containing area, electronic chassis (104) for processing the received optical energy, laser pulse drive (106), and laser cooler (108).

Claims39

Dependent claims

A method for recording an image of a target area using an optoelectronic rangefinder and a passive imaging device, wherein the rangefinder comprises:

transmission means for transmitting optical signals along a transmission axis, receiving means for receiving optical signals reflected by objects located in said target area in time-shifted relationship relative to said optical signals of the transmission means and along a receiving axis substantially parallel to said transmission axis,
optical means mounted upstream of both said transmission means and said receiving means, and providing that the receiving axis is substantially parallel to the transmission axis, the optical means including scanning means for deflecting optical axes of said transmission means and said receiving means in different directions across said target area to obtain coordinates of points of the image, said optical means serving to provide a first spectral bandwidth to transmitted and received optical signals of said rangefinder,
wherein the passive imaging device views said target area via said scanning means, said optical means providing said passive imaging device with a second spectral bandwidth;
wherein the method comprises steps of evaluating data obtained by said rangefinder based on information from said scanning means for determining distance values of the objects in the target area from said time-shifted relationship to provide signals representing distances of the points in the image, and
reproducing individual image points according to data obtained by said rangefinder via said first spectral bandwidth and by said passive imaging device via said second spectral bandwidth, with the coordinates of said image points corresponding to a deflection of said scanning means, said second spectral bandwidth being greater than the first spectral bandwidth to improve clarity and presentation of the image.

2 more elements

An apparatus for recording an image of a target area, comprising:

an optoelectronic rangefinder which includes transmission means for transmitting optical signals along a transmission axis, at least one receiving means of a predetermined spectral sensitivity for receiving optical signals reflected by objects located in said target area in time-shifted relationship relative to said optical signals of the transmission means and along a receiving axis substantially parallel to said transmission axis,
optical means mounted upstream of both said transmission means and said receiving means to define a path of rays, said optical means including at least one beam splitter for supplying part of said reflected optical signals to said at least one receiving means;
a passive imaging device, and scanning means for deflecting said optical axes of said transmission means and said receiving means and an optical axis of said passive imaging device in various directions, wherein said range finder operates with a first spectral bandwidth to obtain range data of points within the target area, said imaging device operates with a second spectral bandwidth to obtain an image of points within the target area,
evaluation means for determining distance values from said time-shifted relationship to provide the signals of a distance image, reproducing means for reproducing individual image points according to data obtained by said range finder via said first spectral bandwidth and by said passive imaging device via said second spectral bandwidth, the coordinates of said image points corresponding to deflection of said scanning means, said evaluation means serving for superposing range data upon the image data for points of the image, said second spectral bandwidth being greater than the first spectral bandwidth to improve clarity and presentation of the image.

1 more element

Dependencies are inferred from the claim text.