Documentation
Command line interface
After completing the installation, the
ALCF commands can be run in the terminal with the alcf program. The program
uses the command line argument format PST
for passing complex command line arguments.
Commands
| Command | Description |
|---|---|
| alcf | the main command |
| alcf auto | peform automatic processing of model or lidar data |
| alcf calibrate | calibrate lidar backscatter |
| alcf convert | convert input instrument or model data to the ALCF standard NetCDF |
| alcf download | download model data |
| alcf lidar | process lidar data |
| alcf model | extract model data at a point or along a track |
| alcf plot | plot lidar data |
| alcf simulate | simulate lidar measurements from model data using COSP |
| alcf stats | calculate cloud occurrence statistics |
Automatic processing
Automatic processing of lidar measurements can be done with the
alcf auto lidar command and performs resampling, noise removal,
cloud detection, calculates cloud occurrence and backscatter histograms and
plots backscatter profiles, cloud occurrence and the backscatter histogram.
alcf auto lidar does not perform initial data conversion from raw instrument
data to NetCDF, and this needs to be done manually by running alcf convert
for instruments which do not produce NetCDF output.
Automatic processing of model data can be done with the alcf auto model
command and performs extraction of model data, runs the lidar simulator,
and processes the simulated backscatter in the same way as alcf lidar.
Manual processing
The commands are usually run in the following order.
ALC observations processing:
alcf convert– convert raw ALC data to NetCDF (only if not in NetCDF already),alcf lidar– produce resampled data,alcf stats– calculate summary statistics from resampled lidar data from step 2.,alcf plot backscatter– plot backscatter profiles,alcf plot backscatter_hist– plot backscatter histogram calculated in step 3.,alcf plot cloud_occurrence– plot cloud occurrence calculated in step 3.,alcf plot cbh– plot cloud base height distribution calculated in step 3.
Model output processing:
alcf model– extract model data at a geographical point or along a ship track,alcf simulate– simulate backscatter based on data from step 1.,alcf lidar– resample simulated backscatter data from step 2.,alcf stats– calculate summary statistics from resampled simulated backscatter data from step 3.,alcf plot backscatter– plot simulated backscatter profiles from step 3.,alcf plot backscatter_hist– plot backscatter histogram calculated in step 4.,alcf plot cloud_occurrence– plot cloud occurrence calculated in step 4.,alcf plot cbh– plot cloud base height distribution calculated in step 4.
NetCDF data files generated in each step are described in the ALCF output and can be previewed in Panoply.