The design of an unusually compact and rugged backscatter lidar system is described in detail. This lidar system, called AROL- 2, was designed for routine monitoring of the boundary layer, tropospheric aerosols, and clouds. In order to support the maximum possible range of observations with minimum investment of labor, the system was specifically designed to be mobile, rugged, and easy to set up and deploy. The lidar system is housed in a weatherproof enclosure, in order to allow operation at sites without sophisticated laboratory facilities. In order to provide maximum flexibiliity and sensitivity in a relatively small package, the lidar system is equipped with both analog and photon counting channels, with two polarization channels to allow for quantitative measurementsof depolarization behavior. Substantial effort has been expended to produce a lidar that is flexible, easy to use, and robust in the field environment.