[IGSMAIL-4646]: More network features at CB web

[Angelyn W. Moore]

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IGS Electronic Mail      10 Oct 15:50:39 PDT 2003      Message Number 4646
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Author: Angelyn Moore/IGS CB

Dear IGS Colleagues,

I'd like to summarize several incremental upgrades to the IGS site
pages at the CB over the past months for those of you who may not
have visited recently.  This refers to the individual sites' pages
which are available via the clickable map or list at
http://igscb.jpl.nasa.gov/network/netindex.html

NRC1 nicely demonstrates most of these, so if you can take a look at
http://igscb.jpl.nasa.gov/network/site/nrc1.html while you read this
message, the "tour" will make more sense.

0. A small map shows you where the site actually is.

1. The data quality plots introduced in IGSMail 3898 now feature
marks showing when a documented station change (receiver, antenna,
or eccentricity) occurred.

2. "Change point analysis" is applied to the data quality plots to
recognize when a change in the character of the time series has
occurred.  These are also marked with a "?" symbol on the graphs.
This is somewhat experimental, but it seems to be fairly good at
identifying changes (even subtle ones) to the slope or noise level.
A good example is the L1 multipath at
http://igscb.jpl.nasa.gov/network/site/aoml.html -- the eye will tell
you that the variation in the data changed around day 255, and the
change point analysis agrees.

3. Below the data quality plots you now find graphs of the
position residuals for the past year, for those sites that appear
in the SINEX combination.  The residuals data is of course provided
by the Reference Frame Coordinator (Rémi Ferland of Natural Resources
Canada).  Also shown is the "IGS spectrum" of each component: the
residual and standard deviation for all IGS sites, with that particular
site highlighted in blue.  This lets the viewer see how that site
compares with what is typical in the IGS network.  The residuals
plots also show the times of documented changes at the station.

I should pause here to say that significant credit for these
implementations goes to Pete Jeziorek, who has since departed the CB
to pursue a Ph.D. at MIT.  Thanks Pete!

4. For hourly sites, you find the recent latency of the hourly
files, and once again how this compares in the "IGS spectrum."

5. For a time we listed which ACs had utilized that site in the
IGS Final orbits during the past quarter.  Now you see a table
showing which ACs used it in which of several IGS products.  This
is realized thanks to Analysis Center Coordinator Gerd Gendt and
the ACs agreeing to provide information on site usage in a way
that we can easily acquire it.  We'll be adding more product types
as the information becomes available.

Eric Richardson has been working on many improvements, most of which
are "behind-the-scenes," in how the CB gathers files and information.
The product usage table, however, is one nice visible manifestation of
this development.

There is further documentation with more details for most of these
items available via links from these pages.  If you have questions
remaining, please feel free to ask.  Your comments are welcome too.

Best regards,
Angie
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   Angelyn W. Moore, Ph.D.            Deputy Director, IGS Central Bureau
   JPL/Caltech                               Angelyn.W.Moore at jpl.nasa.gov
   4800 Oak Grove Dr. MS 238-540                   voice: +1 818 354 5434
   Pasadena CA 91109 USA  http://igscb.jpl.nasa.gov  fax: +1 818 393 6686