The hardware and software for a computer controlled optical radar, or lidar, system are described. The system builds on a previously installed pulsed ruby backscatter lidar, capable of acquiring data at controlled azimuth and elevation angles through the atmosphere. The described system replaces hardwired logic with computer control. Two coupled computers are used to allow a degree of real time control while data are processed. One of these computers reads and controls mount elevation angle, reads the laser energy monitor, and senses firing of the laser. The other computer serves as a user interface, and receives the lidar return data from a digitizer and memory, and the angle and energy information from the other computer. The second computer also outputs data to a disc drive. The software provided with the system is described, and the feasibility of additional software for both control and data processing is explored. Particular attention is given to data integrity and instrument and computer operation in the presence of the high energy pulses used to drive the laser. A previously described laser energy monitor has been improved to isolate it from laser transients. Mount elevation angles are monitored with an absolute angle readout. As a troubleshooting aid, a simulator with an output that approximates the lidar receiver output was developed. Its output is digitally generated and provides a known repetitive signal. Operating procedures are described for standard data acquisition, and troubleshooting is outlined. The system can be used by a relatively inexperienced operator; English sentences are displayed on the system console CRT terminal to lead the operator through data acquisition once the system hardware is turned on. A brief synopsis of data acquired on the system is given. Those data are used as the basis of other referenced papers. It constitutes soundings for over one hundred days. One high point has been operation of the system in conjunction with a balloon borne atmospheric particulate sampling package. The system has also been used occasionally as the transmitter of a lidar system with physically separated receiver and transmitter.

The operating principles and design of an optical receiver for a Light Detection and Ranging (LIDAR) remote sensing instrument are addressed. The performance and limitations of a biaxial monostatic LIDAR system utilizing this design are investigated. The complete optical and structural design of the receiver, including specifications of components are outlined. The thermal stabilization of the detector assembly and the integration of control electronics are described. A detailed discussion of alignment procedures and possible improvements are made. A sample observation is presented with suggestions for fully automating the system.