The Following Script was used to Measure the Elevation Difference for  Line #6 (closest to Earl Pass) of Boreas Day 24:



IDL> @rdsldgeo
% Compiled module: $MAIN$.
Select Data file!
% Compiled module: PICKFILE.
% Compiled module: XREGISTERED.


Opening /boxhill/kstill/boreas96/96bor24/prdata/96072406.geo for input
Reading        23920 records

IDL> baselat=53.216433
IDL> baselon=254.33968
IDL> baselev=402.636

IDL> dist=basedist(c.flat,c.flon,baselat,baselon)
% Compiled module: BASEDIST.

IDL> print,min(dist)
       2.0843519

IDL> closest=where(dist eq min(dist))

IDL> print,'closest shot to earl =',closest
closest shot to earl =       12903

IDL> print,'elevation of closest shot =',c(closest).elevation
elevation of closest shot =      402.595

IDL> print,'elevation difference =',c(closest).elevation-baselev
elevation difference =   -0.0414734