[IGSMAIL-004] Several Topics

[Yehuda]

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IGS Electronic Mail       25-MAY-1992 17:01:53       Message Number 4
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        !!!!!!!!!! THIS FILE CONTAINS TWO MESSAGES !!!!!!!!!!
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>From:     Yehuda Bock
Subject:  Several Topics
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(1) New Canberra Site

We are somewhat confused about the "New Canberra Site". We know that the DS40 
antenna was moved to a temporary new location on 034, 1992 (Any independent 
confirmation will be appreciated). Has it been moved again, and when?
We received notice about this from Ruth Neilan, weeks after the fact.
We have called the temporary mark at Canberra, DS41 to
distinguish from original DS40. We will call the new location DS42 to avoid
confusion with earlier locations. I have room in the name for 7 more moves.
Humor aside, it is imperative that changes at the IGS sites be communicated
quickly to all. The IGS mailbox is a good way to do this.

Update: While writing this message, I received e-mail from Ruth Neilan
informing us that Canberra site has moved to permanent location on day 132.
Thanks Ruth.

(2) New Rogue Raw Data Format

We have been hit quite hard by the new Rogue Raw Data Format ih the last
few weeks. The new format was incorporated in the receivers on the PGGA
triangle with release 7.00 of the Rogue software. Scripps happens to own
two of the Rogue receivers (Pinyon and SIO) on the PGGA and even we were
not informed that the format had changed. Luckily, Werner Gurtner was on
top of format changes very quickly (as he usually is) and he modified his
RINEX translator to deal with the problem. The first point I'm trying to
make is the one from above: that changes at the sites are not being 
communicated to the community on a timely basis. We learned about the first 
DS40 change from our daily analysis only (until we received a message from 
Ruth a few weeks later). We learned about the new format change the hard way, 
by having our automatic download procedures crash.

A second point about the new Rogue format. The data are ordered by satellite
and not by time which makes the RINEX translation very inefficient on a
personal computer. It takes about 5 times longer (at least) to RINEX a 
Rogue file. We do not understand why this change was made. We would
like to encourage JPL to convert back to the old format which was ordered
by time, and ask others who are disturbed by this change to communicate
this message as well. This is a big step backwards, and is further compounded
by the change to 30 sec sampling rate, the increase in the number of stations,
and the increase in the number of satellites.

(3) Performance of Rogue receivers

We are very concerned with the performance of Rogue receivers over the last
few months and implications for IGS campaign. First, on several days before
the installation of new software we see periodic anomalous cycle-slip type
problems in the Rogue phase data. One particularly bad day is February 29,
1992. There are other bad days and I have communicated these problems orally
to Geoff Blewitt at JPL (I have received no response), and the problems show up 
irregularly. It appears that DOD is performing occasional tests which are
causing these problems. Second, since the change to version 7.0 we have noticed
that on some days, several satellites are not being tracked by the Rogue
receivers on the PGGA (the satellites not tracked vary from site to site). We
have communicated this problem to Steve DiNardo and Ulf Lindqwister at JPL.
It appears that the problems have been solved on the PGGA lines.

(4) Summary: We are concerned about tracking problems during IGS and lack
    of communication of important site changes.

(5) We have been sending out weekly status reports on IGS tracking. Can
    anyone help us with this questions?:

-- Any news on Fortaleza and Port Harcourt?

-- What is the status of Metsahovi? I understand that it has been
   upgraded to Rogue receiver - what type?

-- Where can we find Tahiti and Hartebeesthoek data, are they coming
   in regularly?  We have some Hartebeesthoek data but it is quite 
   irregular.

-- What Rogue operating software are being run at the various sites?
   Will they be consolidated by IGS campaign?

Yehuda Bock 5/23/92

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>From:     Martin Hendy
Subject:  orroral gps 
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         ************* ORRORAL GPS RECEIVER STATUS **************

Contrary to recent misinformation, Orroral (Australia) has an
operational full precision pcode GPS receiver (Ashtech) operating on the
same mark as previous GPS was observed. There was a short period prior
to day 136 when there was no receiver in operation. As of day 136,
(Friday 15 May 1992) the pcode receiver has been fully operational and 
will continue to be so. 
The new antenna height to L1/L2 phase centre is 0.062 metre.

The receiver is run continuously 24 hrs. Data is available as daily
rinex files, commencing 00:00:00 hours UTC day 136 1992.

All requests for data must be made by email and / or fax to:
Martin Hendy
Email: mhendy at ise.canberra.edu.au
Fax: + 61 62 01 43 50
Post: c/o AUSLIG, PO Box 2, Belconnen ACT 2616, Australia.

The rinex files will be available within 48 hours of download, however
due to current resource limits can only be made available through
Internet on a request basis. Please supply your full host name when
making a request.

Regards
Martin Hendy
AUSLIG