This text file explains how to read the CIPBL quick optical ascii file.

The CIPBL data set provides optical data for either a pre-defined cirrus "zone"
or a cloud-cleared Planetary Boundary Layer (PBL) only. The data is
provided for every CPL profile (current time resolution is one second).
Since these two layer scenarios are mutually exclusive, only one
will be present at a time, and there will be many times when neither will be
present, either because of atmospheric layer conditions or analysis conditions.
The CPL operates at three wavelengths (wl): 355nm, 532nm, and 1064nm.

**Note: Layer height and optical properties calculations have been adjusted for  
the tilt angle of the lidar beam (up to 30 degrees) during pitchs and rolls.

Below are listed descriptions of all the parameters in each record (one record
per profile).  A record consists of 3 lines of data.

sortie= integer, scaler,         ER-2 id number of flight

year= integer, scaler,           year of flight (2000)

djday= double, scaler,           current decimal day of year to 5 decimal places

hr= integer, scaler,             hour of current profile

minu= integer, scaler,           minute of current profile

sec= integer, scaler,            second of current profile

lat= real, scaler,               latitude of current profile (decimal degrees,
                                 positive= north)
lon= real, scaler,               longitude of current profile (decimal degrees,
                                 positive= east)
pitch= real, scaler,             current aircraft pitch (decimal degrees,
                                 positive= up)
roll= real, scaler,              current aircraft roll (decimal degrees,
                                 positve= right turn) 
heading= real, scaler,           current aircraft azimith heading (decimal
                                 degrees clockwise from north)
plnht= real, scaler,             current aircraft height above mean sea level
                                 (meters)
zcode= integer, vector(3),       integrated ratio technique status (for internal
                                 use only)
vsmo= integer, scaler,           number of vertical bins smoothed (1= no
                                 smoothing)
hsmo= integer, scaler,           number of horizontal bins smoothed (1= no
                                 smoothing)
saturate= real, vector(4)        height (meters amsl) where detector saturation
                                 occurred per channel (-5000 = no saturation,
                                 with channel sequence= 355,532,1064par,1064per
grd_ht= real, scaler,            height (meters amsl) of earth's surface based
                                 on detection of lidar ground stroke (-999= not
                                 detected)
nlay= integer, scaler,           total number of layers detected of any type
                                 in current profile from layer boundary file
type_code= integer, scaler,      layer type (0 for cirrus, 1 for PBL,
                                 -1 for neither present)
lay_topht= real, scaler,         height (meters amsl) of layer top,
                                 (missing= -999)
lay_botht= real, scaler,         height (meters amsl) of layer bottom,
                                 (missing= -999)
tau_cal1= real, vector(3),       layer optical depth estimate per wl, 
                                 (missing= -8.8, invalid= -9.9)
tau_cal1e= real, vector(3),      layer optical depth from error profile per wl
                                 (missing= -8.8, invalid= -9.9)
sp_use= real, vector(3),         extinction-to-backscatter (S ratio) used for
                                 layer per wl, (missing= -8.8, invalid= -9.9)
sp_use_e= real, vector(3),       S ratio for error profile for layer per wl,
                                 (missing= -8.8, invalid= -9.9)
s_source= integer, vector(3),    source of S ratio calculation per wl based on:
     AEROSOLS>
              9= S ratio not calculated                                    
              0= pre-defined generic regional default
              1= educated guess based on recent history at location (PBL)
              2= calculated from available column AOD at location and time (PBL)
              3= pre-calculated from MPL, etc for location and time (PBL)
              4= calculated from the lidar using integrated ratio technique in the
                 clear zone underneath
              6= lowered by a maximum of 15.0sr in order to process down to layer bottom	  
       CLOUDS>
              9= S ratio not calculated
              0= water phase determination based on met temperature profile only
              1= phase based on lidar depolarization ratio and met temperature
              3= special case where 1064nm S ratio is based on 532nm optical depth
                 from integrated ratio technique
              4= calculated straight from the lidar using integrated ratio technique
                 in the clear zone underneath
              5= calculated setting bottom transmission to reflect extinquished signal
              6= lowered by a maximum of 15.0sr in order to process down to layer bottom	    
proctype= integer, vector(3)     type of optical inversion used, (0= backward,
                                 1=forward, 9= layer not processed)
											

***** Read one record (3 lines) of the cipbl ascii data:
 
Line 1:
   sortie,year,djday,hr,minu,sec,lat,lon,pitch,roll,heading,plnht,zcode
	       format= '(I6.5,I5,F10.5,3I3,F7.2,F8.2,3F7.2,F7.0,1X,3I2)'
Line 2:
   vsmo,hsmo,saturate,gnd_ht,nlay,type_code,lay_topht,lay_botht,tau_cal1
	       format= '(4X,2I3,5F7.0,I3,I3,2F7.0,3F7.3)'
Line 3:			 			 
   tau_cal1e,sp_use,sp_use_e,s_source,proctype
	       format= '(4X,3F7.3,6F7.2,1X,6I2)'