REAL Control System Progress

The REAL and duplicates of it have previously operated for long periods of time (i.e. months at CHATS). However, we are currently improving the sensing and control of the system at CSU Chico for two reasons. The first is to make it easy for us to operate it for relatively short periods (minutes to hours) by elimiating the need to drive to the lidar site. Short periods of operation reduce the consumption of electrical power, expendibles such as laser flashlamps, and wear and tear on system components such as pumps and motors. Short periods of system operation are ideal for events like demonstrations to classes, testing of real-time software that is under development, and observing interesting meteorological phenemona. The second reason is the ability to operate the system for long periods (days, weeks, and months). In this more challenging case, we would like for the lidar to monitor its health, make small adjustments to maintain consistent performance, notify operators of potential problems, and shutdown immediately and gracefully if a significant problem is detected.

As of 12 February 2012, we have all the hardware and software in place to turn the power to the REAL system components on and off remotely. The lidar system is on the university network. The electrical power to smaller system components such as the beam steering unit and the seed laser are controlled by an APC 7900 power distribution unit. The power to the Continuum Surelite III pump laser, controlled by a traditional metal key switch on the front of the power and cooling unit, can be rotated to the on or off position with a small computer-controlled servo motor.

Denton Scott, a graduate student with the CSU Chico Department of Electrical and Computer Engineering, will be developing the rest of the REAL control system. It will involve sensing many variables from lidar system components; creating displays and user interfaces; developing algorithms to detect important changes and trends, informing operators of the changes, and taking intelligent and automatic actions as necessary.

Our ultimate goal is continuous and low-cost operation of the REAL over long periods of time for the remote sensing of atmospheric structure (i.e. boundary layer height) and two-component vector wind fields. These products will be calculated in real-time and made available to the public via the web for near-real-time visualization.