SatEvo v0.51                      (SatEvo released 2008 January 21)
============                      (readme updated  2008 January 27)

This "readme" accompanies both the Windows version of SatEvo, built 
under Borland C++ and runnable under Win9x and XP, and
a version built under Linux (specifically Fedora Core 5 though
usable on other flavours of Linux).

Basic operation
---------------

Running the program brings up a prompt for the name of the
element file to be read. This may be any text file containing
elsets in "tle" format - SatEvo will search the file for all
the elsets it contains (it is not fussy about checksums on input).

For every elset SatEvo finds, it will compute a decay date for the
object and it will report this on the screen it it falls within 
1,000 days of the epoch of the elset. If any objects are predicted
to decay within this period, SatEvo also creates a file in the 
same directory as the input file. This file, with the same name as 
the input file but with the filename extension ".dk", contains a 
copy of the screen output from this phase.

If a single decaying object is identified, you are next prompted 
for the filename for the orbital evolution. This evolution 
continues for 30 days, or until decay, whichever comes first.

If multiple decaying objects are identified, you are prompted
for the elset number of the one you wish to evolve and, as before,
for the name of the output file for the evolution. After this file 
is created, you may select another elset for evolution, and so on 
until you enter an elset number of zero.

More advanced operation
-----------------------

To control aspects of the operation of SatEvo, UNIX-like 
flags/parameters may be provided on the command-line by which the 
program is invoked. In addition, the name of the input element file
may also be provided on the command line. Several control flags
exist for my experimental purposes and are not documented here. Others
of more general use are:

Lifetime flag -LDays. The default operation is for SatEvo to report
the expected decay date if it falls within 1,000 days of the elset
epoch. Inserting, for example, "-L5002" on the command line will
instruct SatEvo to report decays which occur within 5,002 days of the
elset epoch.

Prediction limit -PDays. By default, SatEvo evolves a selected orbit
for 30 days or until decay, whichever comes first. A command-line entry
of, for example, "-P4.5" will end the evolution after 4.5 days rather
than 30 days.

Q-factor -Qn.nnnn. This experimental facility allows the internal 
quantity Q to by varied by the factor provided. If not given, the 
factor defaults to 1.0. For a given input elset, the act of changing 
the Q-factor is to change the predicted lifetime by the same factor.

Solar flux flag -Fnnn This allows the user to specify the prevailing solar 
flux (the F10.7 index). The default value is 150, but this is 
inappropriate near times of sunspot minimum (as at present
in early 2008) when a -F70 setting may be preferable.

Flags may be combined in any order.

Known problems under Windows
----------------------------

SatEvo requires that the file CC3260MT.DLL be in your path. If you 
get an error to say that this file was not found, then I believe 
it can be fixed by downloading the file from 
  http://www.dll-files.com/dllindex/dll-files.shtml?cc3260mt
and placing it your appropriate system directory. By default, this is
        C:\Windows\System (Windows 95/98/Me), 
        C:\WINNT\System32 (Windows NT/2000), 
        or C:\Windows\System32 (Windows XP).
Thanks to Chuck Boren for the heads-up about this.

Acknowledgements
----------------

I thank Russell Eberst and Mike McCants for encouragement and
assistance during my writing of SatEvo.

    Comments on this program are invited via email to me at 
                  alan@wingar.demon.co.uk.

The current version of SatEvo is available via my SatEvo WWW page at
             http://www.wingar.demon.co.uk/satevo/

Alan
-- 
 Alan Pickup | COSPAR site 2707:   55d53m48.7s N   3d11m51.2s W    156m asl
 Edinburgh   |
 Scotland    |

