Control system for a high pulse-energy atmospheric lidar

A master's thesis that develops, tests, and implements a control system for a high pulse-energy atmospheric lidar system is presented. The control system senses in real-time system variables such as transmitter component temperature, pressure, and energy and diameter of high energy laser pulses and makes decisions on whether action is required. The control program can immediately and gracefully shut down the lidar if the system variable measurements exceed operator defined thresholds. It can also inform operators of changes in system status. The control system includes a feedback loop to increase the Neodymium-doped Yttrium Aluminum Garnet laser ashlamp voltage incrementally thereby providing improved transmit pulse-energy stability over the 23 to 30 day lifetime of a ashlamp set. This control system facilitates unattended operation of the lidar over long periods of time with more uniform performance and the safety of a control system that can head off potentially catastrophic system failures.