diff -r ec9e68b53a3b -r d55a57e732be README.md
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+++ b/README.md	Thu Nov 10 16:35:00 2016 +0200
@@ -1,1 +1,20 @@
-polarizatio_simulator
+Calculation of pollarization correction factors for atmospheric lidar system, developed by Volker Freudenthaler (LMU).
+
+# Theory
+The theoretical basis of the script is described in detail in :
+
+>Freudenthaler, V.: About the effects of polarising optics on lidar signals and the Δ90 calibration,
+Atmos. Meas. Tech., 9, 4181-4255, doi:10.5194/amt-9-4181-2016, 2016
+>http://www.atmos-meas-tech.net/9/4181/2016/
+
+
+# Use
+To run the script you need to:
+
+1. Create a file describing your system settings and parameters. You can find an example file in the "system_settings"
+   folder. Give a descriptive name and save it in the "system_settings" folder.
+
+2. Open the "lidar_correction_ghk.py" file, and set the variable InputFile to the filename you chose in step 1.
+
+3. Run "python lidar_correction_ghk.py"
+