The platform characteristics of the simulation is for the NPOESS/OP Coherent DWL point design. The simulation represents the accumulation of "strong" lidar data products that are considered to be very good (from a signal processing point of view). However, degradation of the data due to opaque clouds is included. The horizontal resolution is 200 km X 200 km and the vertical resolution is 1 km above the PBL and 250 m in the PBL. The simulation is approximately a 7.5 hour period run starting on Feb. 7 1993 0000Z.

The following is a list of the contents of a single data record of simulated Space-based Doppler lidar line-of-sight data products.

		

 

 month/day/year						 (MMDDYY)	integer

 time of data product					 (s)		real

 latitude of product					 (deg)		real

 longitude of product					 (deg)		real

 altitude (above MSL) of product  			 (km)		real

 elevation angle                        		 (deg)          real

 azimuth angle (CW from True North)   	   		 (deg)		real

 total number of accumulated (distributed) DWL 		  		integer
 estitmates used to produce gridded LOS wind
 (set to -1 for clustered DWL LOS wind)		

 atmospheric depth of product layer			 (m) 		real

 Attenuated backscatter source quality flag	  			integer
 0 - aerosol or molecule backscatter
 1 - 100 (from a very thin cirrus to a total opaque cloud
 	
 gridded DWL los velocity	 (m/s)		real
 (positive away from the Satellite)

 standard deviation of accumulated DWL los estimates 	 (m/s)		real

NOTE: The standard deviation of accumulated DWL los estimates should not to be confused with the representativeness of the gridded DWL los velocity. The standard deviation of accumulated DWL los estimates is a measure of the variability of the wind within the sample volume as measured at the lidar sample points. A measurement of representativeness is more a function of the total number of accumulated DWL estimates used to produce the single gridded LOS wind estimate.

We have chosen to provide the simulated data products in this format to reduce the file sizes from which would have been the case if all range gate estimates, useful or not, were saved. It is estimated that the total DWL LOS products (in ascii) simulated over the 30 days of the T213 Nature Run will be around 8 gigabytes.

A compressed form of the data file, T213.lv1.Z (last modified on 10/07/98), can be obtained from ftp://ftp.swa.com/pub/npoess

The FTP site also contains BUFR versions of the data set at 0000Z and 0600Z for NCEP.

The simulated data set has been tested against SWA's forward model.