Subject: Bugs in GAMIT 9.71

From: Bob King <[email-masked]>
Date: Mon, 20 Jul 1998 08:46:01 -0400 (EDT)

GAMITeers 

In GAMIT release 9.71 there is a bug in the yaw code for PRN 13,
causing it to be modeled in 'fixed' mode (as during eclipse) throughout
its orbit.  You can correct the problem by substituting get_dusk.f from
pub/gps/updates/incremental_updates on bowie.mit.edu for the subroutine
by the same name in gamit/orbits.  Version 9.71 has now been replaced
in the updates/source directory by 9.72, which has this bug corrected.
              
There is an assignment bug in gamit/solve that causes the loose solution
to fail unless the affected arrays happen to be zero.  The bug is long-standing
and has caused no problem with Solaris and HP systems since memory is 
initialized to zero, but will affect LINUX/G77 compilations.  The fix
is to replace sversn.f and lwzen.f with the routines in /incremental updates.

A second incremental update, to gamit/lib/hisub.f affects only data using 
the Ashtech Marine antennas.  
              
In updates/tables, there is a new version of svant.dat that has Block IIA
satellites correctly identified with block code 3 (rather than 2).  The
use of 2 heretofore was intentional to accomodate use of GAMIT releases
earlier than 9.63, which would not recognize block code 3 (or 4 for Block IIR).  
Note that there is no code in 9.72 (or earlier) that needs to make a distinction 
between Block II and Block IIA, but there will be with the next release as we
implement the new Berne radiation-pressure model.   If you are using a 
release of GAMIT prior to 9.63, you should change the code 3 entries to '2'.
(But of course there are many reason why you should update from this old
releas   

Table leap.sec has been updated to incorporate the leap second announced last
week for the end of this year.  The new table will be valid through the end 
of 1999.  

--bob