Data / Science Data Products / VAPs

MPLCMASK

Cloud mask from Micropulse Lidar

Baseline VAP

Example plots of normalized relative backscatter (NRB), linear depolarization ratio (LDR), and the cloud mask for ARM’s Southern Great Plains observatory on October 18, 2018.

The MPLCMASK value-added product (VAP) implements a cloud detection algorithm to provide cloud boundaries from the ARM micropulse lidar (MPL) systems. The VAP provides the number of cloud layers as well as each layer’s cloud top and cloud base at 30-meter and 30-second resolution. A cloud mask is compiled at this temporal and spatial resolution and is the primary lidar cloud mask for input to the Active Remote Sensing of Clouds (ARSCL) VAP.

In addition to retrieving cloud boundaries, MPLCMASK applies instrument corrections to the lidar measurements and calculates the linear depolarization ratio (LDR) using the methodology developed by Flynn et al. (2007). The current version of MPLCMASK applies the instrument corrections as described in Campbell et al. (2002) with modifications specific to a polarized fast-switch MPL system.