Direct and almucantar sun measurements from Prede POM-01L.

	All times are local times.
	

	The complete dataset consists of 4 files. Each file is named using the timestamp when it was taken with the following extensions:
		- .dat file contains original unprocessed data from the instrument
		- .met file contains meteorological information
		- .obs file contains information on the time, location and scattering angles
		- .out file contains calculated particle size distribution, optical depth data, phase function


	.dat file
		The raw data from the instrument. Each measurement is indicated with a timestamp line, as shown in the example below

		time,H or V (for horizontal or vertical scan),date,site information
		09:59:28,H,2006/03/07,Clalmanalco, NS run
		
		After that line, there is 7 columns of data (each column corresponds to a certain wavelength).
		The number of rows corresponds to the number of scattering angle measured and specified in the .obs file.

		The instrument outputs voltages measured by the detector.

	
	.met file
		The meteorological data contains pressure and ozone information with timestamp and GPS coordinates.

	
	.obs file
		Information on the project, GPS location and set of all possible scattering angles defined for the instument.


	.out file
		The output data calculated using Skyrad.PACK v.4.2. 
		The data subsets are separated with metadata as in the followinf example

		  TNo yyyy mm dd Hour   Long    Lat    Hs    SA(max) SA  r i  error  (LP)
		    1 2006  3  4 11.41  -98.91  20.01  63.11  50.0  30.0 0 0  0.0365 ( 4) **   

			This is a line of information on conditions for measurement and
			analysis of analyzed data.  There are serial number(TNo), year(yyyy),
			month(mm), day(dd), time(Hour), longitude(Long), latitude(Lat), solar
			height(Hs), maximum scattering angles for measurement(SA(max)) and
			for use(SA), retrieval flags for complex refractive index(r and i),
			retrieval error(error), number of iteration(LP) and convergence flag
			(*_or ** or __) in order from the left.

			If retrieval flag for complex refractive index(r/i) is positive, output
			value of the part corresponding to it(real/imaginary) is a retrieval.
			If it is zero, that is not a retrieval, but a value assumed to be the
			initial value of retrieval.


		The next section of the data subset is the refractive indices as shown in the following example

		 Refractive Indices
		  WL     0.4000    0.5000    0.6750    0.8700    1.0200
		  Cr     1.5000    1.5000    1.5000    1.5000    1.5000
		  Ci   -0.00500  -0.00500  -0.00500  -0.00500  -0.00500

			Where
			WL : wavelength in micron
			Cr : real part of complex refractive index
			Ci : imaginary part of complex refractive index


		The next section of the data subset is the columnar particle size distribution as shown in the following example

	     Radius     Volume
	   1.209E-06   2.023E-11
	   1.768E-06   1.148E-10
	   2.586E-06   5.626E-10
	   3.782E-06   5.116E-09
	   5.530E-06   5.211E-08
	   8.087E-06   3.002E-07
	   1.183E-05   8.507E-07
	   1.729E-05   1.176E-06
	   2.529E-05   7.807E-07
	   3.698E-05   2.625E-07
	   5.408E-05   1.512E-07
	   7.908E-05   3.726E-07
	   1.156E-04   6.879E-07
	   1.691E-04   1.025E-06
	   2.473E-04   1.707E-06
	   3.617E-04   2.470E-06
	   5.289E-04   3.156E-06
	   7.734E-04   8.651E-06
	   1.131E-03   2.633E-05
	   1.654E-03   3.943E-05

			where
			Radius: radius in centimeter
			Volume: volume spectrum dV/dlnr in cm3/cm2



		The next section of the data subset is the particle cross section as shown in the following example

	 Cross sections
	  WL     0.4000    0.5000    0.6750    0.8700    1.0200
	  OPT    0.3010    0.2030    0.1059    0.0665    0.0798
	  TA     0.1942    0.1576    0.1161    0.0931    0.0836
	  WA     0.8776    0.8612    0.8330    0.8118    0.8057  

			where
			WL : wavelength in micron
			OPT: (measured) optical thickness
			TA : (retrieved) optical thickness
			WA : single scattering albedo



		The next section of the data subset is the sun position data as shown in the following example


	 fg    TH     FI     SCA     AUR        AURC
	 -9   26.9    0.0    0.0   8.273E-05  -1.000E+00
	  1   26.9    6.6    3.0   4.951E-01   5.109E-01
	  1   26.9    8.9    4.0   3.275E-01   3.439E-01
	  1   26.9   11.1    5.0   2.600E-01   2.745E-01
	  1   26.9   15.5    7.0   2.046E-01   2.141E-01
	  1   26.9   22.2   10.0   1.723E-01   1.810E-01

			where
			fg  : flag for availability
			TH  : zenith angle in degree
			FI  : (relative to solar) azimuth angle in degree
			SA  : scattering angle in degree
			AUR : measured sky radiance
			AURC: retrieved sky radiance

			  Regarding flag for availability:
			     fg = 1: available/ use for retrieval
			         -1: not available/ no use for retrieval (abnormal positive data)
			          0: no use for analysis (out of usable scattering angles)
			         -9: meaningless (direct data or negative data)


	The next section of the data subset is the phase function data as shown in the following example


	 THETA POBSN(IW=1,NW)
	   0.0 3.642E+02 2.964E+02 2.305E+02 1.844E+02 1.520E+02
	   0.2 3.077E+02 2.655E+02 2.170E+02 1.777E+02 1.480E+02
	   0.4 1.868E+02 1.914E+02 1.811E+02 1.591E+02 1.365E+02
	   0.6 8.641E+01 1.132E+02 1.346E+02 1.325E+02 1.193E+02


			where
			THETA         : scattering angle in degree
			POBSN(IW=1,NW): normalized phase functions for the respective
        			             wavelengths





	Contact information

	Bill Eichinger					Piotr Lewandowski
	University of Iowa				University of Iowa
	william-eichinger@uiowa.edu			piotr-lewandowski@uiowa.edu
	319-358-1053					319-358-7409