Advanced sine wave modulation of continuous wave laser system for atmospheric CO2 differential absorption measurements

Abstract

In this theoretical study, modulation techniques are developed to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described for making simultaneous online/offline differential absorption measurements. Amplitude and Phase Shift Keying (PSK) modulated IM carriers, in addition to a hybrid pulse technique are investigated that exhibit optimal autocorrelation properties. A method is presented to bandwidth limit the ML sequence based on a filter implemented in terms of Jacobi theta functions that does not significantly degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

Accepted for publication in Applied Optics

References in corpus (2)

• Non-linear swept frequency technique for CO2 measurements using a CW laser system
• A Low Cost Remote Sensing System Using PC and Stereo Equipment

Cited by in corpus (1)

• Field Evaluation of Column CO2 Retrievals from Intensity-Modulated Continuous-Wave Differential Absorption Lidar Measurements during ACT-America