ahmilb@houu64$bhphorizon

 BHPHORIZON -  Build Horizon Trace                                    

 bhphorizon < stdin > stdout [optional parameters]                    

 bhphorizon builds 'horizon traces' by loading horizon times from     

 an ASCII file to a trace as samples. Existing seismic data are deleted

 from traces. The output from bhphorizon is a dataset consisting of   

 trace headers with horizon times as samples.                         

 bhphorizon uses the trace header 'trid' to determine if input traces 

 have already been populated with one or more horizons. If trid is not

 = 910, it is assumed that the input data is seismic. All trace values

 are replaced by horizon data, and the trid is set to 910.            

 If the input data already have trid=910, the horizon value is        

 added to the end of the trace. For horizon traces, the header 'ns' is

 set to the number of horizons, and 'dt' is set to 1000.              

 Required parameters: none                                             

 Optional parameters:                                                  

 keys=ep,cdp   Trace headers to use as keys. At least 2 keys must be  

               present, with no upper limit.                           

    OR                                                                

 phdr=ep shdr=cdp Old-style key specification                         

 npicks=1      Number of horizons/picks in each ASCII record          

               Multiple horizons may be loaded in one pass            

               The total number of fields expected in each ASCII record

               is npicks plus the number of keys specified in keys=   

 file=horz.dat ASCII file containing key values and horizon data       

               on each line, separated by spaces.                     

 extrap=no     For traces whose key values are outside the limits of  

               the horizon data in the ASCII file, extrap=no returns a

               null horizon value. extrap=yes returns the nearest     

               horizon value.                                         

               For traces whose keys values are inside the limits of  

               the horizon data, bilinear interpolation is used to assure

               that a non-null horizon value is loaded if 2 keys are specified.

               If more than 2 keys are specified, the nearest non-null horizon

               value is used.                                         

 bias=0        The bias value is added to each horizon time/depth.    

 scalar=1      Each horizon value is multiplied by scalar before adding bias.

 null=-999.25  Value to use as null for primaries,secondaries not found.