Scientific aspects of the optical depth sensor

The optical depth sensor (ODS) is designed for the monitoring of Martian dust opacity over a long period of time. Additionally, it could provide valuable information on aerosol size distribution and on cloud coverage at sunset and sunrise. The instrument was developed for the MARS96 Russian mission which unfortunately failed and the ATMIS meteorological package on the NETLANDER mission which unfortunately was cancelled. The instrument's main attractive features for a meteorological mission to Mars are its low requirements of energy and data transfer resources. The paper describes the working principle and theoretical performance of ODS, simulated with a Martian aerosol and cloud model.