System for profiling objects on terrain forward and below an aircraft utilizing a cross-track laser altimeter

A laser-based system disposed on-board an aircraft for identifying a target concealed by a common object on the terrain from a plan view of the common object from the aircraft during flight, said system comprising:

• a forward looking cross track laser altimeter operative to emit pulsed laser beams at a predetermined rate along line swept paths forward and downward at a predetermined angle to the flight path of the aircraft, said pulsed laser beams being line swept back and forth across a ground track forward the aircraft and as the aircraft moves along its flight path, said line sweeps serpentining an area of terrain forward the aircraft, said laser altimeter for receiving returns of said pulsed laser beams from said common object, said target concealed thereby and surrounding terrain in said area forward the aircraft;
• said laser altimeter operative to measure times-of-flight and line sweep positions of said returns and generate for each return a data profile comprising range and line sweep position thereof based on the corresponding time-of-flight and position measurements, said data profiles being output from the laser altimeter;
• and
• a first unit coupled to the laser altimeter for receiving said return data profiles and for assembling the data profiles of a predetermined number of consecutive line sweeps to form composite data of a three-dimensional image of said common object and target concealed thereby for each of a plurality of different approach flight paths, wherein each three-dimensional image providing a view orientation of said common object and target concealed thereby based on the corresponding approach flight path associated therewith;
• said first unit for integrating the composite data of said different viewed three-dimensional images to form a comprehensive three dimensional image of the common object and target concealed thereby, and for identifying the concealed target from said comprehensive three dimensional image.

A self-contained, laser altimeter disposable on-board an aircraft for profiling objects on terrain forward of the aircraft during flight, said laser altimeter comprising:

• a laser source for generating pulsed laser beams at a predetermined rate;
• a first configuration of optical elements for guiding the pulsed laser beams along a first optical path and including an optical element configurable to direct the pulsed laser beams from the first optical path to paths forward and downward at a predetermined angle to the flight path of the aircraft, wherein the pulsed laser beam paths are guided along a path on the terrain forward the aircraft;
• said optical element for receiving returns of said pulsed laser beams from the terrain and objects on the terrain along said terrain path forward the aircraft and directing said returns along a second optical path;
• a light detector;
• a second configuration of optical elements for guiding said returns from said second optical path to said light detector which produces a return signal in response to a detection of each return;
• a first circuit coupled to said light detector and governed by the return signals for measuring times-of-flight of said returns and generating time-of-flight signals corresponding thereto;
• a second circuit coupled to said first circuit for generating data profiles for the returns, each data profile comprising a range based on the time-of-flight signal of the corresponding return;
• a small enclosed housing including a windowed area;
• wherein said above recited elements are packaged within said small enclosed housing;
• and
• wherein the pulsed laser beams and returns are passed respectively from and to said housing through said windowed area.