Why are laser footprint shape parameters not available for low energy campaigns?

Several parameters help quantify the shape of the GLAS laser footprint, which change slightly for each campaign. These parameters are:

GLAS HDF5 ParameterGLAS HDF5 Parameter DescriptionGLAS HDF5 Data Set
d_tpintensity_avgTransmit pulse intensity - frame averageGLAH14, GLAH15
d_tpazimuth_avgTransmit pulse azimuth - frame averageGLAH06
d_tpeccentricity_avgTransmit pulse eccentricity - frame averageGLAH14, GLAH15
d_tpmajoraxis_avgTransmit pulse major axis - frame averageGLAH14, GLAH15

These parameters are valid on most campaigns, but in the later campaigns (after Laser 2D), the laser energy was too weak to be able to compute the pulse shape, resulting in values of 0. More details about these parameters can be found in the GLAH06 Product Data Dictionary.

Last Updated Aprili 2020