Changing Overlap Correction Factors - BLVIEW - CL31

The overlap correction factors affect the default live plots.

You can define whether overlap correction factors are applied to the data, and which overlap correction factors to use.

On your computer, go to the following folder:

C:\Program Files (x86)\Vaisala\BL-View\config.

Open the file bl_calc_srv.ini in Windows Notepad.

For each device, the file contains 2 settings that are related to overlap correction:

USE_OVERLAP_CORRECTION=[S]"YES"
OVERLAP_CORRECTION_FILE=[S]"C:\Program Files (x86)\Vaisala\BL-View\config\overlap_correction_profile.dat"


Parameter	Description/Value
USE_OVERLAP_CORRECTION	Defines whether to apply overlap correction factors to data No (default) Yes
OVERLAP_CORRECTION_FILE	Defines the location and name of the overlap correction file. Default location is C:\Program Files (x86)\Vaisala\BL-View\config Default file name is overlap_correction_profile.dat

If you want to define device-specific overlap correction factors, create separate overlap correction files for each device.
1. For example, for 2 devices, create the following files in folder
  C:\Program Files (x86)\Vaisala\BL-View\config:
  - overlap_correction_profile_CL31_Helsinki.dat
  - overlap_correction_profile_CL51_Vantaa.dat
  Copy the file content from the existing file overlap_correction_profile.dat.
2. Go to folder C:\Program Files (x86)\Vaisala\BL-View\config and open the file bl_calc_srv.ini in Windows Notepad.
3. In bl_calc_srv.ini, define the location and name of the overlap correction files.
```
[CEILOMETER_1]
...
OVERLAP_CORRECTION_FILE=[S]"C:\Program Files (x86)\Vaisala\BL-View\config\overlap_correction_profile_CL31_Helsinki.dat"
```
```
[CEILOMETER_2]
...
OVERLAP_CORRECTION_FILE=[S]"C:\Program Files (x86)\Vaisala\BL-View\config\overlap_correction_profile_CL51_Vantaa.dat"
```
To adjust the near-range performance of a ceilometer, adjust the overlap correction factors.
Go to folder C:\Program Files (x86)\Vaisala\BL-View\config and open the correct overlap correction profile file in Windows Notepad, and edit the information.

The overlap correction factor is used to multiply the backscatter value at the specified height in level 2 (L2) profile. The following example shows how to change the overlap correction factor for 10 m (3 ft 3 in) from 1.02 to 1.00.

Original settings:
```
TERENO Fendt correction factors
1.3    Version of this correction file
1.2    Sensitivity correction factor

Overlap correction factors
1.02		10 m
1.01		20 m
1.01		30 m
1.02		40 m
...
```
Modified settings:
```
TERENO Fendt correction factors
1.3    Version of this correction file
1.2    Sensitivity correction factor

Overlap correction factors
1.00		10 m
1.01		20 m
1.01		30 m
1.02		40 m
...
```
Above 360 m (1181 ft), the overlap correction factor is 1.0.
Save and close the file.

Changing Overlap Correction Factors - BLVIEW - CL31 - CL51

BL‑View User Guide