Lockheed Martin Corporation

Loral Vought Systems Corporation

Other

Stuart W Flockencier

Edward Max Flowers

Don A Larson

Lionel D Liebman

A LADAR apparatus and a method for use in receiving a LADAR signal are disclosed. The apparatus includes an optical pickup capable of picking up a plurality of optical signals; a timing synchronization reference; a time domain multiplexer capable of multiplexing the optical signals into a multiplexed optical signal relative to the timing synchronization reference; and an optical detector capable of detecting the multiplexed optical signal. The method include time domain multiplexing a plurality of LADAR signals into multiplexed LADAR signal; detecting the multiplexed LADAR signal; and demultiplexing the detected LADAR signal.

Single detector receiver for multi-beam LADAR systems

The invention an optical system and a method for automatically controlling the gain of a receiver in an optical system. The optical system includes an optical receiver, a pulse capture unit, and an automatic gain control. The pulse capture unit includes a capture unit capable of capturing an optical signal received by the optical receiver; and, a process unit capable of processing the captured optical signal. The automatic gain control is capable of controlling the gain of the optical receiver responsive to the content of the processed optical signal. The method includes comparing the intensity of at least one returned pulse, and typically a plurality of returned pulses, to a predetermined value; and controlling the gain of an optical detector responsive to the comparison. In addition, the maximum gain is controlled by a noise limit in some implementations.

Programmable pulse capture device with automatic gain control

A method and apparatus is provided for detecting a pulse in a signal. In one aspect of the invention, a method comprises digitizing the signal into a plurality of samples; repeatedly convolving each one of at least a portion of the buffered samples R times, wherein R&gt;1; and detecting the received signal's center of energy from the convolution results. In a second aspect, an apparatus comprises a analog-to-digital converter capable of digitizing the received signal to produce a plurality of samples; a convolution circuit, including a matched filter for convolving the digitized signal at a second sampling rate; a buffer capable of storing the samples and serially outputting each of the samples R times, where R&gt;1, to the convolution circuit; and a detector for detecting the digitized signal's center of energy from the output of the convolution circuit.

Method for increasing single-pulse range resolution

A Finite Impulse Response (FIR) digital signal processing circuit uses a double-accumulator technique to drastically reduce the number of multiply-accumulate operations which are necessary per sample of input data. The amount of reduction is dependent upon the shape of the filter function to be convolved. A double-accumulator (D-A) can be implemented by first providing a set of D-A coefficients, which are derived from the filter coefficient stream (FCS). Each D-A coefficient is multiplied by a separate input data sample. The products are summed together along with the result of a previous multiplication of the same D-A coefficients with different input data samples. This first sum is added to another number to form a second sum. The other number is the previous value of the second sum. The second sum is the result. The derived D-A coefficients are fewer and simpler than that required by the conventional FIR implementation. Since multipliers are complex, costly, bulky and limited in speed, the D-A method can lessen these constraints.

Double-accumulator implementation of the convolution function

An energy pulse capture system senses, receives, and processes signals reflected from a target. In an illustrative embodiment, light pulses are reflected off of a target, received by optical equipment, converted into analog electrical signals, and then processed to obtain information therefrom. The invention basically identifies targets by measuring the time delay between a transmitted signal and a received or 'return' signal. The invention includes a windowing system to more efficiently process digitized electrical signals representing the return signals. The windowing system effectively defines a 'window' in memory within which the return signal is stored, and 'locks' on to this window to reduce time spent searching for the return pulses among other data. In another aspect of the invention, a real time return system is used to more efficiently process the electrical signals representing the return pulses. The real time return system detects the maximum amplitude of the received signal in real time, and stores the current value of a counter used to clock data into memory, thereby facilitating later use of the stored counter value to locate signals representative of the return signal in the memory. The invention also concerns a timing delay system, which conserves memory of the invention by delaying storage of data until a return pulse is actually received.

System for processing reflected energy signals

A gate-array pulse capture device senses, receives, and processes signals derived in response to received laser energy, i.e., signals reflected from a target. The reflected signals are initially in the form of light pulses and are converted into analog electrical signals in the detection module and passed on to the pulse capture device. The pulse capture device determines the time delay between the transmitted and received signals and the intensity of the reflected pulse, and then compares its shape to a predetermined pattern to locate the position and intensity of the peak. This information is then used by an image processor to locate and identify targets.

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Cedar Hill, TX, United States of America

Stuart W Flockencier