[IGSMAIL-6110]: New discontinuities in IGS10P09.snx

[Paul Rebischung]

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IGS Electronic Mail      18 Mar 09:51:17 PDT 2010      Message Number 6110
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Author: Paul Rebischung

Dear Colleagues,

Following the Chile earthquake, discontinuities had to be introduced for
several South American stations in the IGS cumulative SINEX solution. The
concerned stations are, for the moment:

CONZ, SANT, VALP, CFAG, BUE1, LPGS, UNSA

Unfortunately, three of these stations (CONZ, SANT, LPGS) were still RF
stations before the earthquake so that the set of usable IGS05 RF stations
is now even more sparse. (See the huge gap in South Pacific-America-Atlantic
at ftp://igs-rf.ign.fr/pub/RF_1573.png.)

The inspection of residuals time series led us to introduce retrospectively
four other discontinuities in IGS10P09.snx. Combined and cumulative SINEX
will not be resubmitted for older weeks. But the new cumulative solution
results of course from a new stacking which includes these four new
discontinuities:

PERT 09:319:00000 - Unknown
GOPE 09:348:37800 - Antenna & Receiver Change
OHI3 10:022:71100 - Antenna Change
WTZS 10:056:48600 - Antenna Change

The case of PERT (also an RF station) is not clear. It had an abnormal
behaviour during weeks 1558-1562, so that a discontinuity had first been
introduced by Rimi Ferland. Then, PERT came back to a more usual position,
and the discontinuity was removed. But with a little more hindsight, we are
now able to observe a small but permanent shift, mainly in the East
component, so that we re-introduced the discontinuity.

By the way, we would like to inform all of you that a list of all
discontinuities present in the IGS cumulative solution is available at
ftp://igs-rf.ign.fr/pub/discontinuities/soln.snx. It is now also included in
the cumulative SINEX files themselves.

On the same FTP site, you can find other by-products of the IGS RF
combination such as coordinates and residuals time series or time series
extracted from the weekly summary files. A dedicated website will soon be
set up to give a more friendly access to these resources.

Best regards,

The new RF coordination team
(Please contact us at igs-rf at ign.fr.)