Most recent messages are at the top. Older messages are down below.
From: Ted Fritz IN%"FRITZ@buasta.bu.edu" 16-AUG-1996
18:42
To: IN%"epg@uss-enterprise.bu.edu"
CC:
Subj: For your information
Here is a collection of e-mail messages indicating that we may have a timing
problem with both the CAMMICE and CEPPAD DPUs that needs to be understood.
This
has come about due to a spin phase offset of 32 degrees required but not
understood to line the CAMMICE HIT and MICS fluxes up with a direction
perpendiculr to the local magnetic field. Ideas???
Ted
******************************************************************************
14-AUG-1996 14:30 MAIL
From: IN%"joe_fennell@qmail2.aero.org" "Joe Fennell"
To: IN%"Fritz@bu.edu" "T A Fritz"
CC:
Subj: Magaz issue
Ted:
I talked to Rich Selesnick again about his experience with MAGAZ on Ceppad.
He
says that he had to apply a 28 degree fudge factor to Magaz to get good
angular
distributions with HIST. That is close to the 32 degrees you are talking
about.
He gets the two different half spin samples to match nicely and has also
made
average angular distributions that indicate his 28 degree offset factor
works
well.
Joe F.
******************************************************************************
14-AUG-1996 18:30 MAIL
From: BUASTA::FRITZ
To: IN%"joe_fennell@qmail2.aero.org"
CC: FRITZ,CHEN,SPJELDVIK,ANDERS,SPENCE
Subj: RE: Magaz issue
Joe,
Does Rich add or subtract the offset of 28 degrees to MAGAZ to get
agreement. In the plots of the HIT and MICS intensities Jiasheng plots MAGAZ
without modification directly on the HIT data and gets excellent agreement
with
the peak in the pad implying that there is 90 degrees difference of HIT
wrt to
the actual projection of the B-vector in the X,Y plane. [See
http://buspace.bu.edu/EPG/jiasheng/chen.html] Since HIT is located 58 degrees
toward +Y from the +X axis this implies the 32 degree offset we have been
proposing. For MICS the same good agreement is achieved when 40 degrees
is
subtracted from MAGAZ, not added. This implies that MICS crosses the 90
degree
direction before HIT and that the s/c is rotating in the direction -Z, not
+Z.
Harlan mentioned that you had come to a similar conclusion. Is the offset
Rich
came up with consistent with this interpretation?
Ted
******************************************************************************
14-AUG-1996 18:56 MAIL
From: BUASTA::FRITZ
To: IN%" t.e.moore@msfc.nasa.gov"
CC: FRITZ,SPENCE,DIRAC2::FENNELL
Subj: MAGAZ
Tom,
We have looked at the MAGAZ in the s/c housekeeping and found those values
to be identical to the ones in the CAMMICE TM. I am attaching a note from
Joe
Fennell indicating that the CEPPAD HIST response is consistent with a 30
degree
offset in MAGAZ. This means that three energetic particles instruments are
consistent in that manner. I am curious as to how strongly you feel about
the
correctness of MAGAZ and the consistency of the TIDE response with it. I
invite
you to look at some CAMMICE summary plots in progress of being posted on
our
BUSPACE Web site at the following URL:
http://buspace.bu.edu/EPG/jiasheng/chen.html
Thanks,
Ted
******************************************************************************
15-AUG-1996 11:07 MAIL
From: BUASTA::FRITZ
To: IN%"t.e.moore@msfc.nasa.gov"
CC: FRITZ,SPENCE,DIRAC2::FENNELL
Subj: RE: MAGAZ
Tom,
I will certainly appreciate your feedback. If it does turn out that MAGAZ
is correct as it comes from the s/c, this will imply a large and unknown
time
offset in the way we process our CAMMICE/CEPPAD instrument data. The DPUs
for
both CAMMICE and CEPPAD are based on different types of microprocessors
but do
attempt to take data in a spin synced manner. Both DPUs were designed and
constructed at the Aerospace Corporation by different individuals and the
software has been constructed by different individuals but anything is possible
wrt timing.
Ted
******************************************************************************
16-AUG-1996 13:41 MAIL
From: IN%"t.e.moore@msfc.nasa.gov"
To: IN%"FRITZ@buasta.bu.edu"
CC:
Subj: RE: MAGAZ
Ted,
We're still looking, but my folks are standing pretty firm that MAGAZ is
putting
our look direction right on the field at the center of the loss cones in
our
most energetic populations (500 eV), to within at most a few degrees error.
Plasma ram or convection is incapable of affecting this to any signficant
degree. As I mentioned before, we had a 20 deg. error until we got our
spacecraft mounting correct, so be sure to check that as well as any other
offsets that are applicable (?).
Regards,
Tom
__________________________________________________________________
National Aeronautics Thomas E. Moore, Chief
and Space Administration Space Plasma Physics Branch
MARSHALL SPACE FLIGHT CENTER Space Sciences Lab/Code ES83
Huntsville, AL 35812 T.E.Moore@MSFC.NASA.gov
phone: 205-544-7633 fax: 205-544-5244
******************************************************************************
16-AUG-1996 18:13 NEWMAIL
From: BUASTA::FRITZ
To: IN%"t.e.moore@msfc.nasa.gov"
CC: FRITZ
Subj: RE: MAGAZ
Tom,
Thanks for the feedback. I did get John Wainwright to fax me the
instrument orientation information in mid July. So unless he was using the
wrong set of documents we should know our orientation. The CEPPAD IES sensor
has a light sensitivity that we can probably use to do some further internal
testing. Thanks for your help.
Ted
******************************************************************************
Produced and Maintains the CCR Web Pages.