Command line interface
alcf lidar
alcf lidar - process lidar data
The processing is done in the following order:
- noise removal
- calibration
- time resampling
- height resampling
- cloud detection
- cloud base detection
Usage: alcf lidar <type> <lidar> <output> [<options>] [<algorithm_options>]
Arguments:
type
: lidar type (see Types below)lidar
: input lidar data directory or filenameoutput
: output filename or directoryoptions
: see Options belowalgorithm_options
: see Algorithm options below
Types:
blview
: Vaisala BL-VIEW L2 productchm15k
: Lufft CHM 15kcl31
: Vaisala CL31cl51
: Vaisala CL51cl61
: Vaisala CL61cosp
: COSP simulated lidardefault
: the same format as the output ofalcf lidar
minimpl
: Sigma Space MiniMPLmpl
: Sigma Space MPL (converted via SigmaMPL)mpl2nc
: Sigma Space MPL (converted via mpl2nc)
Options:
altitude
: Altitude of the instrument (m). Default: Taken from lidar data or0
if not available.calibration: <algorithm>
: Backscatter calibration algorithm. Available algorithms:default
,none
. Default:default
.couple: <directory>
: Couple to other lidar data. Default:none
.cl_crit_range: <range>
: Critical range for thefix_cl_range
option (m). Default: 6000.cloud_detection: <algorithm>
: Cloud detection algorithm. Available algorithms:default
,none
. Default:default
.cloud_base_detection: <algorithm>
: Cloud base detection algorithm. Available algorithms:default
,none
. Default:default
.fix_cl_range
(experimental): Fix CL31/CL51 range correction (ifnoise_h2
firmware option if off). The critical range is taken fromcl_crit_range
.lat: <lat>
: Latitude of the instrument (degrees North). Default: Taken from lidar data ornone
if not available.lon: <lon>
: Longitude of the instrument (degrees East). Default: Taken from lidar data ornone
if not available.noise_removal: <algorithm>
: Noise removal algorithm. Available algorithms:default
,none
. Default:default
.output_sampling: <period>
: Output sampling period (seconds). Default:86400
(24 hours).tlim: { <low> <high> }
: Time limits (see Time format below). Default:none
.tres: <tres>
: Time resolution (seconds). Default:300
(5 min).tshift: <tshift>
: Time shift (seconds). Default:0
.zlim: { <low> <high> }
: Height limits (m). Default:{ 0 15000 }
.zres: <zres>
: Height resolution (m). Default:50
.
Algorithm options:
- Cloud detection:
default
: cloud detection based on backscatter thresholdcloud_nsd: <n>
: Number of noise standard deviations to subtract. Default:5
.cloud_threshold: <threshold>
: Cloud detection threshold (sr^-1.m^-1). Default:2e-6
.
none
: disable cloud detection
- Cloud base detection:
default
: cloud base detection based cloud mask produced by the cloud detection algorithmnone
: disable cloud base detection
- Calibration:
default
: multiply backscatter by a calibration coefficientcalibration_file: <file>
: calibration file
none
: disable calibration
- Noise removal:
default
:noise_removal_sampling: <period>
: Sampling period for noise removal (seconds). Default: 300.
none
: disable noise removal
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.
Examples:
Process Vaisala CL51 data in cl51_nc
and store the output in
cl51_alcf_lidar
, assuming instrument altitude of 100 m above sea level.
alcf lidar cl51 cl51_nc cl51_alcf_lidar altitude: 100