Automatic Lidar and Ceilometer

Command line interface

alcf-stats – Calculate cloud occurrence statistics.


alcf stats [<options>] [--] <input> <output>


Arguments following -- are treated as literal strings. Use this delimiter if the input or output file names might otherwise be interpreted as non-strings, e.g. purely numerical file names.


  • input: Input filename or directory.
  • output: Output filename or directory.


  • blim: <value>: Backscatter histogram limits (1e-6 Default: { 5 200 }.
  • bres: <value>: Backscatter histogram resolution (1e-6 Default: 10.
  • bsd_lim: { <low> <high> }: Backscatter standard deviation histogram limits (1e-6 Default: { 0.001 10 }.
  • bsd_log: <value>: Enable/disable logarithmic scale of the backscatter standard deviation histogram (true or false). Default: true.
  • bsd_res: <value>: Backscatter standard deviation histogram resolution (1e-6 Default: 0.001.
  • bsd_z: <value>: Backscatter standard deviation histogram height (m). Default: 8000.
  • filter: <value> | { <value> ... }: Filter profiles by condition: cloudy for cloudy profiles only, clear for clear sky profiles only, night for nighttime profiles, day for daytime profiles, none for all profiles. If an array of values is supplied, all conditions must be true. For night and day, lidar profiles must contain valid longitude and latitude fields set via the lon and lat arguments of alcf lidar or read implicitly from raw lidar data files if available (mpl, mpl2nc). Default: none.
  • filter_exclude: <value>: Filter by a mask defined in a NetCDF file, described below under Filter file.
  • filter_include: <value>: The same as filter_exclude, but with time intervals to be included in the result. If both are defined, filter_include takes precedence.
  • tlim: { <start> <end> }: Time limits (see Time format below). Default: none.
  • zlim: { <low> <high> }: Height limits (m). Default: { 0 15000 }.
  • zres: <value>: Height resolution (m). Default: 50.

Time format

YYYY-MM-DD[THH:MM[:SS]], where YYYY is year, MM is month, DD is day, HH is hour, MM is minute, SS is second. Example: 2000-01-01T00:00:00.

Filter file

The NetCDF file must define a variable time_bnds (float64), which are time intervals to be excluded from the result. time_bnds must have two dimensions time of an arbitrary size and bnds of size 2. The first and second column of the variable should contain the start and end of the interval, respectively. time_bnds must be valid time in accordance with the CF Conventions.


Calculate statistics from processed lidar data in alcf_cl51_lidar and store the output in

alcf stats alcf_cl51_lidar