Read the top part of NRLGenData.f
   To use NRL data, in  Cosmos/cosmos/condc.h, 
ATMOSPHERE 
   must be set to 3  and the library must be updated.
To do so,  if Zcondc.h is ready,
1)  go to Cosmos/Tracking/Atmosphere
2)  touch cstandatmos0.f
3)  make clean; make
This is ok for using NRLGenData.f; To compile it,
come here and
  make clean; make

But for the entire cosmos, it is better to
4)  remove all in Cosmos/cosmos/lib/$ARCH/*
5)  and remake the entire library, i.e at
    Comsmos/
    make veryclean; make
    

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Execution:
  For execution, you must make a input file like template.d
  (the last two lines must be gvien as you like). Then
  
NRLGenData$(ARCH) < yourInputfile > yourOutputFile

This will create two files: one is
NRLAtmos.d
which may be used as input file for Cosmos execution when
 ATMOSPHERE in Zcondc.h is 3.
 To do so, give the file name in AtmosFile in Namelist data.
Longitude and latitude values are taken from the data so
the they must be consistent with those in Namelist.

To avoid confusion, usually better to keep AtmosFile blank
and give NRL_peridon data (4 integer data) like
  day1 day2  hour1 hour2
which specify the period from hour1 to hour2 during
day1 to day2.
   dayi  in 1 to 365  (i=1,2)  (neglect leap year)
   houri in 0 to 24 
If day1 > day2, new year step-over is made.
Also, if hour1 > hour2, midnight step-over is made.

Atmosphere data is prepared as the average during this period.
The longitude and latitude are taken from those in Namelist.

