HOW TO GET THE REQUIRED PROGRAMS (ROUTINES) AND DATA:
-----------------------------------------------------
[This information was provided by Bill Schar and Bob 
Benson, GSFC, Code 692; xrwbs@lepvx2.gsfc.nasa.gov,
u2rfb@lepvx2.gsfc.nasa.gov]

Copy the following command file:

COPY LEPVAX::DATA1:[U2RFB_DATA]JACKSONCOPY.COM *.*/LOG

After this command file has been copied to your account you can invoke 
it to get the rest of the files and routines by doing the following:

@JACKSONCOPY

Then you will need to COMPILE all of the routines and LINK them 
together.  You can link them together by using the command file MAIN.COM 
(i.e.; @MAIN).

Once the files are on your system the input file NHINPUT.DAT will have 
to be modified to suit your needs.  Right now it is set up for direct 
input of SATELLITE POSITION parameters.




Description of how to use John Jackson Inversion program:

Input:  Magnetic field model data for FIELDG is required for all 
versions of the complete inversion program.  This input of 28 lines 
(4(F4.0, 2F8.5)) is read by the subroutine READ.  It is followed by two 
title lines (2(20A4)).  These titles were used on the plot labels in the 
older version that had plot outputs.  Next are input data for each 
ionogram for which true-height inversion of the ionogram extraordinary 
(X) trace is desired.  The first line has the format 
(3I10,4X,3I2,2I10,6X,4I1,I5,I2,I3) for the following variables:  number 
of points scaled along the ionogram X trace (I10, called N), year (I10, 
called IYR), julian day (I10, called IDY), hour (I2, called IH), minute 
(I2, called IM), and second (I2, called IS) (note: time is in UT); a 
flag (I10, called MAP) which is 0, 1 or 2 (Note: MAP = 0 if the 
satellite motion is neglected and the satellite location (as calculated 
from the world-map program) is read in directly (the program currently 
uses 0), MAP = 1 if satellite motion is included and the satellite 
location is to be interpreted from world map data input and the electron 
gyrofrequency (fH) is to be determined based only on the magnetic-field 
model (in this case fH at the satellite location is not read in), MAP = 
2 is the same as 1 with the exception that fH as scaled from the 
resonances and cutoffs on the ionogram is also read in so that a 
correction to the magnetic-field model can be made for the starting 
point of the X-trace true-height inversion routine - as of 20 June 1995 
this correction is also made for the case MAP = 0.); a satellite 
identification (I10, called ISAT = 1 for Alouette 1, 2 for Alouette 2, 3 
for ISIS 1, and 4 for ISIS 2 (Note: ISAT is used for two purposes:  
first, if ISAT = 3 a correction is made for the nonlinear ISIS 1 
frequency sweep in the intervals from 2.0 to 3.0 MHz and between 5.0 and 
6.0 MHZ; second, if the option to include satellite motion is selected 
(MAP = 2 or 3) then the specific sounder frequency-sweep rate for the 
satellite identified by ISAT is used to calculate the satellite position 
for each scaled point along the ionogram X trace.); 4 processing codes 
used to determine the ionogram analysis procedure (4I1, called ICODE(n) 
with n = 1 to 4) (Note: ICODE(1) = 1 for fixed satellite position and 
known X trace cutoff frequency (fX), ICODE(1) = 2 for fixed satellite 
position and unknown fX, ICODE(1) = 3 for variable satellite position 
and known fX, ICODE(1) = 4 for variable satellite position and unknown 
fX; currently, ICODE(1) = 1 and ICODE(n) for n = 2, 3 or 4 are not used 
- see MAIN program for additional comments.);  A flag (I5, called IORD) 
which is 1 if the O-trace is to be calculated; a flag (I2, called IP) 
which is 1 if plotting is desired with contours, 2 plotting but no 
contours, or 0 if no plotting or contours are desired (Note: currently 
this flag has been deactivated because the plot routines used on the 
original version of the program are no longer used.);  a flag (I3, 
called METH) which is 1 for linear in log(N) laminations, 2 for 
parabolic in log(N) (default is 2 which is currently used).  The next 
input depends on the value of MAP.

If MAP = 0, i.e., the satellite motion is neglected, then the next line 
should contain: Height (F10.4, called HT), DIP angle (F10.4, called 
DIP), gyrofrequency (F10.4, called FHS), Geographic Latitude (F10.4, 
called DLAT), and Longitude (F10.4, called DLONG).  

If MAP = 1, i.e., the satellite motion is included but fH is not read 
in, then 4 world map data entries follow, each line of which should 
contain:  2 world map data entries (GMT, LAT, LONG, HGT, GMT, LAT, 
LONG, HGT (8F10.4)).

If MAP = 2, i.e., the satellite motion is included and fH is read in, 
then 4 world map data entries follow, each line of which should contain:
2 world map data entries (GMT, LAT, LONG, HGT, GMT, LAT, LONG, HGT 
(8F10.4)).  These are followed by a line containing fH (F10.4).


The last several lines hold scaled ionogram data.  There are 4 pairs of 
virtual height (km) and frequency (MHz) per line (8F10.4).  These points 
must be in frequency ascending order.  More information on the input can 
be found within the source programs.

AN EXAMPLE OF THE ABOVE INPUT FOLLOWS:

  1.-23.0583  3.2650  5.-22.6867  5.1283 15.-21.2433  9.2167 30.-17.8350 
13.2450
 45.-13.2383 17.2783 60. -7.8317 12.5733 75. -1.9983  8.9350 90.  3.9017  
4.4567
105.  9.5333  0.2433120. 14.5717 -2.7050135. 18.7117 -3.7400150. 21.6750 
-2.6850
165. 23.2333  0.0433180. 23.2700  3.1700195. 21.7850  5.6483210. 18.9117  
6.4000
225. 14.8767  4.9233240.  9.9500  1.4267255.  4.4333 -3.4633270. -1.3733 
-8.7317
285. -7.1500-13.2967300.-12.5617-16.0133315.-17.2433-16.0367330.-20.8200-
12.9167
345.-22.9483 -7.0933360.-23.3917  0.2250365.-23.1483  2.6733
  1.-22.9967  3.6250  5.-22.6033  5.4583 15.-21.1050  9.4800 30.-17.6283 
13.3683
 45.-12.9817 14.2433 60. -7.5433 12.4217 75. -1.7000  8.7100 90.  4.1967  
4.2200
105.  9.8033  0.0483120. 14.8050 -2.8150135. 18.8917 -3.7417150. 21.7883 
-2.5883
165. 23.2733  0.1183180. 23.2300  3.3217195. 21.6717  5.7450210. 18.7333  
6.3800
225. 14.6450  4.8050240.  9.6817  1.2083255.  4.1417 -3.7133270. -1.6700 
-8.9833
285. -7.4383-13.4683300.-12.8200-16.0800315.-17.4550-15.9333330.-20.9650-
12.6783
345.-23.0133 -6.7233360.-23.3667  0.5983365.-23.0950  3.0317
  1.-23.0167  3.5083  5.-22.6300  5.3567 15.-21.1483  9.7400 30.-17.6950 
13.3200
 45.-13.0617 14.2617 60. -7.6367 12.4567 75. -1.7933  8.7850 90.  4.1017  
4.2800
105.  9.7183  0.1133120. 14.7300 -2.7900135. 18.8367 -3.7300150. 21.7517 
-2.6233
165. 23.2600  0.0833180. 23.2433  3.2750195. 21.7067  5.7317210. 18.7900  
6.3900
225. 14.7167  4.8550240.  9.7667  1.2783255.  4.2333 -3.6267270. -1.5750 
-8.9083
285. -7.3467-13.4117300.-12.7383-16.0683315.-17.3883-15.9683330.-20.9183-
12.7633
345.-22.9917 -6.8433360.-23.3750  0.4750365.-23.1117  2.9267
  1.-23.0350  3.4050  5.-22.6550  5.2583 15.-21.1917  9.3150 30.-17.7583 
13.3000
 45.-13.1433 14.2717 60. -7.7250 12.5317 75. -1.8883  8.8617 90.  4.0117  
4.3883
105.  9.6333  0.1883120. 14.6600 -2.7167135. 18.7800 -3.7150150. 21.7167 
-2.6117
165. 23.2483  0.0483180. 23.2533  3.2650195. 21.7417  5.7117210. 18.8450  
6.4233
225. 14.7900  4.8933240.  9.8500  1.3600255.  4.3267 -3.5567270. -1.4817 
-8.8250
285. -7.2533-13.3750300.-12.6550-16.0517315.-17.3183-16.0233330.-20.8717-
12.8483
345.-22.9717 -6.9833360.-23.3817  0.3483365.-23.1283  2.7900
   ISIS 1 IONOGRAMS USED TO COMPARE AKR WITH SPS (1979)
  EVENT NO. 5 (DATA AS OF MAY 22,1980)
        26        71       315    182448         0         4      3       1 
0
 1398.4000   66.7700    0.8010   37.3800  -67.6300
    0.0000    1.4360  213.7500    1.4440  266.2500    1.4520  390.0000    
1.4600
  408.7500    1.4680  468.7500    1.4760  528.7500    1.4920  607.5000    
1.5160
  690.0000    1.5480  742.5000    1.5720  858.7500    1.6600 1008.7500    
1.8040
 1121.2500    1.9810 1177.5000    2.1510 1211.2500    2.4270 1215.0000    
2.7480
 1211.2500    3.2990 1222.5000    4.1700 1237.5000    5.0680 1271.2500    
7.6920
 1286.2500    8.2630 1290.0000    8.5040 1308.7500    8.9060 1342.5000    
9.3370
 1395.0000    9.5710 1447.5000    9.7270

The input for this run should be stored under the name of  
"NHINPUT.DAT".

There also is an input file which was needed if producing plots from 
this program.  The plot capability was removed (by commenting out all 
calls to the plot routine) because the plot package that was used in not 
currently supported on LEPVAX.  The file (called NE1.DAT), however, 
should be retained in the input.


Output: The output will appear in the file "NHOUTPUT.DAT".