Raman Lidar Independent Water Vapor Mixing Ratio Calibration and Diagnosis

Raman Lidars can provide combined high spatial and temporal resolution water vapor measurements. However, until recently, Raman Lidars lacked a means of independent water vapor mixing ratio calibration and relied on other instruments such as radiosonde and microwave radiometers for water vapor mixing ratio calibration. Here we show the use of a calibration technique called the lamp mapping technique (LMT) that allows the Raman Lidar water vapor measurements to be calibrated independently of another measurement of water vapor. We also show comparisons between the calibration constant determined using the lamp mapping technique and that determined using the radiosonde. The LMT is also applicable as a diagnostic tool for Lidar systems. We will review the use of the lamp mapping technique for independent water vapor calibration on two Raman lidar systems and illustrate the use of the same technology for diagnosing various lidar system components.