Lidar polarisation GHK-parameter and error calculation: system_settings/optic_input_example

system_settings/optic_input_example_lidar.py@ef8a64173c96 (annotated)

system_settings/optic_input_example_lidar.py

Thu, 16 Feb 2017 21:34:49 +0100

author: Volker Freudenthaler <volker.freudenthaler@lmu.de>
date: Thu, 16 Feb 2017 21:34:49 +0100
changeset 23: ef8a64173c96
parent 21: 857c95060313
child 26: 28b5510492ba
permissions: -rw-r--r--

Changed parameter name for laser degree of linear polarization from bL to DOLP.
Added loop for DOLP uncertainty.
Input file changed accordingly.

 # This Python script will be executed from within the main lidar_correction_ghk.py
 # Probably it will be better in the future to let the main script rather read a conguration file,
 # which might improve the portability of the code within an executable.
 # Due to problems I had with some two letter variables, most variables are now with at least
 # three letters mixed small and capital.
 # To be used with lidar_correction_ghk.py ver. 0.9.5 and larger
 # Do you want to calculate the errors? If not, just the GHK-parameters are determined.
 Error_Calc = True
 # Header to identify the lidar system
 #
 EID = "xx"				# Earlinet station ID
 LID = "example lidar" 	# Additional lidar ID (short descriptive text)
 print("    Lidar system :", EID, ", ", LID)
 # +++ IL Laser and +-Uncertainty
 DOLP, dDOLP, nDOLP = 0.995, 0.005,  1	#degree of linear polarization; default 1
 RotL, dRotL, nRotL 	= 0., 	2., 	1	#alpha; rotation of laser polarization in degrees; default 0
 # +++ ME Emitter optics and +-Uncertainty;  default = no emitter optics
 DiE, dDiE, nDiE 	= 0.0, 	0.1, 	0	# Diattenuation
 TiE 		        = 1.0		                # Unpolarized transmittance
 RetE, dRetE, nRetE 	= 0., 	180., 	0	# Retardance in degrees
 RotE, dRotE, nRotE 	= 0., 	1.0, 	0	# beta: Rotation of optical element in degrees
 # +++ MO Receiver optics including telescope
 DiO,  dDiO, nDiO 	= 0.0, 	0.1,    1
 TiO 				= 1.0
 RetO, dRetO, nRetO 	= 0., 	180., 	0
 RotO, dRotO, nRotO 	= 0., 	0.5, 	0	#gamma: Rotation of optical element in degrees
 # +++++ PBS MT Transmitting path defined with TS, TP, PolFilter extinction ratio ERaT, and +-Uncertainty
 #   --- Polarizing beam splitter transmitting path
 TP,   dTP, nTP	 	= 0.95,	0.01,   1
 TS,   dTS, nTS	 	= 0.02,	0.01,   1
 RetT, dRetT, nRetT	 = 0.0,	180., 	0 # Retardance in degrees
 #   --- Pol.Filter behind transmitted path of PBS
 ERaT, dERaT, nERaT	 = 0.001, 0.001, 1 # Extinction ratio
 RotaT, dRotaT, nRotaT = 0.,   1.,    1 # Rotation of the Pol.-filter in degrees; usually 0° because TP >> TS, but for PollyXTs it can also be 90°
 #   --
 TiT = 0.5 * (TP + TS)
 DiT = (TP-TS)/(TP+TS)
 DaT = (1-ERaT)/(1+ERaT)
 TaT = 0.5*(1+ERaT)
 # +++++ PBS MR Reflecting path defined with RS, RP, PolFilter extinction ratio ERaR  and +-Uncertainty
 #   ---- for PBS without absorption the change of RS and RP must depend on the change of TP and TS. Hence the values and uncertainties are not independent.
 RS_RP_depend_on_TS_TP = False
 #   --- Polarizing beam splitter reflecting path
 if(RS_RP_depend_on_TS_TP):
     RP, dRP, nRP        = 1-TP,  0.00, 0    # do not change this
     RS, dRS, nRS        = 1-TS,  0.00, 0    # do not change this
 else:
     RP, dRP, nRP        = 0.05,  0.01, 1    # change this if RS_RP_depend_on_TS_TP = False
     RS, dRS, nRS        = 0.98,  0.01, 1    # change this if RS_RP_depend_on_TS_TP = False
 RetR, dRetR, nRetR	    = 0.0,   180., 0
 #   --- Pol.Filter behind reflected path of PBS
 ERaR, dERaR, nERaR	  = 0.001, 0.001, 1 # Extinction ratio
 RotaR, dRotaR, nRotaR = 90.,   1.,    1  # Rotation of the Pol.-filter in degrees; usually 90° because RS >> RP, but for PollyXTs it can also be 0°
 #   --
 TiR = 0.5 * (RP + RS)
 DiR = (RP-RS)/(RP+RS)
 DaR = (1-ERaR)/(1+ERaR)
 TaR = 0.5*(1+ERaR)
 # +++ Parallel signal detected in the transmitted channel => Y = +1, or in the reflected channel => Y = -1
 Y = +1.
 # +++ Calibrator Location
 LocC = 3 #location of calibrator: 1 = behind laser; 2 = behind emitter; 3 = before receiver; 4 = before PBS
 # --- Calibrator Type used; defined by matrix values below
 TypeC = 3	#Type of calibrator: 1 = mechanical rotator; 2 = hwp rotator (fixed retardation); 3 = linear polarizer; 4 = qwp; 5 = circular polarizer; 6 = real HWP calibration +-22.5°
 # --- MC Calibrator parameters
 if TypeC == 1:  #mechanical rotator
 	DiC, dDiC, nDiC 	= 0., 	0., 	0
 	TiC = 1.
 	RetC, dRetC, nRetC 	= 0., 	0., 	0
 	RotC, dRotC, nRotC 	= 0., 	0.1, 	1	#constant calibrator offset epsilon
 	# Rotation error without calibrator: if False, then epsilon = 0 for normal measurements
 	RotationErrorEpsilonForNormalMeasurements = True	# 	is in general True for TypeC == 1 calibrator
 elif TypeC == 2:   # HWP rotator
 	DiC, dDiC, nDiC 	= 0., 	0., 	0
 	TiC = 1.
 	RetC, dRetC, nRetC 	= 180., 0., 	0
 	#NOTE: use here twice the HWP-rotation-angle
 	RotC, dRotC, nRotC 	= 0.0, 	0.1, 	1	#constant calibrator offset epsilon
 	RotationErrorEpsilonForNormalMeasurements = True	# 	is in general True for TypeC == 2 calibrator
 elif TypeC == 3:   # linear polarizer calibrator. Diattenuation DiC = (1-ERC)/(1+ERC); ERC = extinction ratio of calibrator
 	DiC, dDiC, nDiC 	= 0.9998, 0.0001, 1	# ideal 1.0
 	TiC = 0.4	# ideal 0.5
 	RetC, dRetC, nRetC 	= 0., 	0., 	0
 	RotC, dRotC, nRotC 	= 0.0, 	0.1, 	0	#constant calibrator offset epsilon
 	RotationErrorEpsilonForNormalMeasurements = False	# 	is in general False for TypeC == 3 calibrator
 elif TypeC == 4:   # QWP calibrator
 	DiC, dDiC, nDiC 	= 0.0, 	0., 	0	# ideal 1.0
 	TiC = 1.0	# ideal 0.5
 	RetC, dRetC, nRetC 	= 90., 	0., 	0
 	RotC, dRotC, nRotC 	= 0.0, 	0.1, 	1	#constant calibrator offset epsilon
 	RotationErrorEpsilonForNormalMeasurements = False	# 	is  False for TypeC == 4 calibrator
 elif TypeC == 6:   # real half-wave plate calibration at +-22.5°  => rotated_diattenuator_X22x5deg.odt
 	DiC, dDiC, nDiC 	= 0., 	0., 	0
 	TiC = 1.
 	RetC, dRetC, nRetC 	= 180., 0., 	0
     #Note: use real HWP angles here
 	RotC, dRotC, nRotC 	= 0.0, 	0.1, 	1	#constant calibrator offset epsilon
 	RotationErrorEpsilonForNormalMeasurements = True	# 	is in general True for TypeC == 6 calibrator
 else:
     print ('calibrator not implemented yet')
     sys.exit()
 # --- LDRCal assumed atmospheric linear depolarization ratio during the calibration measurements in calibration range with almost clean air (first guess)
 LDRCal,dLDRCal,nLDRCal= 0.009, 0.005, 1     # spans the interference filter influence
 # ====================================================
 # NOTE: there is no need to change anything below.
 # --- LDRtrue for simulation of measurement => LDRsim
 LDRtrue = 0.4
 LDRtrue2 = 0.004
 # --- measured LDRm will be corrected with calculated parameters GHK
 LDRmeas = 0.3
 # --- this is just for correct transfer of the variables to the main file
 DOLP0, dDOLP, nDOLP = DOLP, dDOLP, nDOLP
 RotL0, dRotL, nRotL = RotL, dRotL, 	nRotL
 # Emitter
 DiE0,  dDiE,  nDiE  = DiE,  dDiE, 	nDiE
 RetE0, dRetE, nRetE = RetE, dRetE, 	nRetE
 RotE0, dRotE, nRotE = RotE, dRotE, 	nRotE
 # Receiver
 DiO0,  dDiO,  nDiO  = DiO,  dDiO, 	nDiO
 RetO0, dRetO, nRetO = RetO, dRetO, 	nRetO
 RotO0, dRotO, nRotO = RotO, dRotO, 	nRotO
 # Calibrator
 DiC0,  dDiC,  nDiC  = DiC,  dDiC, 	nDiC
 RetC0, dRetC, nRetC = RetC, dRetC, 	nRetC
 RotC0, dRotC, nRotC = RotC, dRotC, 	nRotC
 # PBS
 TP0,   dTP,   nTP   = TP,   dTP, 	nTP
 TS0,   dTS,   nTS   = TS,   dTS, 	nTS
 RetT0, dRetT, nRetT	= RetT, dRetT, nRetT
 ERaT0, dERaT, nERaT	= ERaT, dERaT, nERaT
 RotaT0,dRotaT,nRotaT= RotaT,dRotaT,nRotaT
 RP0,   dRP,   nRP   = RP,   dRP,   nRP
 RS0,   dRS,   nRS   = RS,   dRS,   nRS
 RetR0, dRetR, nRetR	= RetR, dRetR, nRetR
 ERaR0, dERaR, nERaR	= ERaR, dERaR, nERaR
 RotaR0,dRotaR,nRotaR= RotaR,dRotaR,nRotaR
 LDRCal0,dLDRCal,nLDRCal=LDRCal,dLDRCal,nLDRCal

Mercurial > public > atmospheric_lidar_ghk / annotate

system_settings/optic_input_example_lidar.py@ef8a64173c96 (annotated)

system_settings/optic_input_example_lidar.py