Wider use of lidar systems requires that they continue to become smaller, less expensive, and more reliable. To address this need, ERIM International has developed the M10 portable atmospheric lidar to measure aerosol profiles and cloud optical and physical properties. The system is based on a compact Nd:YAG laser and operates at either 532, 1064, or 1574 nm. The 1574 nm wavelength was added recently to address eye safety concerns. The system has been ruggedized for unattended field use and has been on several data collection campaigns recently. Date and analyses are presented from the Program for Regional Oxidants: Photochemistry, Emissions, and Transport Summer 1997 field study in Pellston, Michigan, and also from the Hyperspectral Day/Night Radiometry Assessment field study at Eglin AFB in Florida.