### Documentation

## Supported ALCs

The following ALCs are supported:

- Lufft CHM 15k
- Sigma Space MiniMPL
- Vaisala CL31
- Vaisala CL51
- CALIPSO/CALIOP (lidar simulation only)

### Vaisala CL31, CL51

Type: `cl3`, `cl5`

Vaisala CL31 and CL51 are ceilometers which use near-infrared wavelength of 910 nm. The instruments store backscatter in DAT files. These can be converted to NetCDF with the `alcf convert cl51 <input> <output>` command, where `<input>` and `<output>` are input and output directories, respectively. The NetCDF files can then be used as input to the `alcf auto lidar` and `alcf lidar` commands. Alternatively, you can use the tool cl2nc to convert DAT files to NetCDF.

The 910-nm wavelength band used by CL31 and CL51 is affected by water vapour absorption lines (Wiegner et al., 2019). ALCF currently does not support simulating water vapour absorption, and it is not taken into account in the calibration process.

### Sigma Space MiniMPL

Type: `mpl` (`mpl2nc`)

Sigma Space MiniMPL is a lidar which use visible wavelength of 532 nm. The instrument stores backscatter in MPL files. These can be converted to NetCDF using the SigmaMPL software. The NetCDF files can then be used as input to the `alcf auto lidar` and `alcf lidar` commands. The tool mpl2nc can also convert MPL files to NetCDF. Use the lidar type `mpl2nc` with `alcf auto lidar` and `alcf lidar` to process data from mpl2nc.

### Lufft CHM 15k

Type: `chm15k`

Lufft CHM 15k is a ceilometer which uses near-infrared wavelength of 1064 nm. The instrument stores backscatter in NetCDF files, which can be used directly with the ALCF commands `alcf auto lidar` and `alcf lidar` without conversion.

### CALIPSO/CALIOP

Type: `caliop`

CALIOP is a spaceborne lidar on board of the CNES-NASA satellite CALIPSO. ALCF supports lidar simulation of a spaceborne lidar at 532 nm, i.e. it can produce simulated backscatter profiles from atmospheric model data. Therefore, this lidar type can be used with `alcf simulate` and `alcf auto model`, but not with `alcf lidar` or `alcf auto lidar`.