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OLD NEWS  from the Ocean Loading Provider


BUG REPORTS

Aug. 13, 2012: An error in the post-processor (used for sites near coasts) caused small errors (sub-mm) in loading coefficients. The problem was fixed today. From Nov. 26, 2012, on, the sites are marked on the charts.
Nov. 28, 2012: olgt.pl had another error. Updated today, please download again.
Nov. 8, 2011: olgt.pl had an error. Please download again.


Please re-issue requests if both of the following two criteria apply
  • The BLQ record indicates that OLMPP was used ("Computed by OLMPP")
  • The job was carried out between June 15 and July 25, 2011
Consider to re-issue requests for stations in the Pacific area if your results have been computed before June 15, 2011, even long before.
Our sincere thanks go to Andreas Richter and Mathias Fritsche who brought the problem to our attention.
Hans-Georg and Machiel
Read here the details.



OLD NEWS


June 13, 2012: New tide models   (all have a resolution of 1/81/8)

GOT4.8 from NASA Goddard Space Flight Center and University of Maryland (Richard Ray).
In this update of GOT4.7 only the S2 tide is affected.

July 29, 2011: Centre-of-mass coefficients:
text added and a wager issued.

July 29, 2011: A note on mass conservation: It should be noted that from the earliest beginnings of this site, the parameters (gravity, tilt, displacements) imply a correction to obtain a global mass balance. We may consider to offer you an alternative, a radio button to switch it off.

June 20, 2011: mGal is not a metric unit, and the numbers in the BLQ result files lack numerical resolution.
Thus a change in conventions was made:
Henceforth, if you select Gravity, the results are presented in μm/s2.
However, you can select "mGal" if you still prefer that.

Aug 27, 2009: BUG REPORT
An error in the refinement stage OLMPP was detected. Results are affected at the 10% level in the case of stations near the coast with increasing error toward high latitudes. The problem started after a revision on July 07, 2009.  Affected results are recognizable on behalf of a signature  Computed by OLMPP  or  Computed by OLCMC/OLMPP  in the BLQ output.
Thanks to Kristian Breili and Matt King to point out the problem.
The problem has been solved ar UT 13:45 today, Aug 27, 2009.

Dec. 24, 2008: BLQ-files format
BLQ format, header record #5 changed:

$$
  ONSALA           
$$ GOT00.2_PP ID: 2008-12-23 23:54:30
$$ Computed by OLCMC/OLMPP by H G Scherneck, Onsala Space Observatory, 2008
$$ Onsala,                              lon/lat:   11.9264   57.3958   10.00
------------------------------------------------^column 49
--------------------------------------------------------------------^column 69

Column 69: Station height (F8.2)




June 30, 2008: New tide model
New tide model: EOT08a from DGFI Munich
with Acknowledgments to Roman Savcenko and Wolfgang Bosch


May 7, 2008: New tide models
New tide models implemented: GOT4.7 and Andersen 2006
References are not shown yet on our reference page - in progress (promise!)


April 10, 2008: Article Published

N. T. Penna, M. S. Bos, T. F. Baker, and H.-G. Scherneck
Assessing the accuracy of predicted ocean tide loading displacement values
J. Geodesy, DOI 10.1007/s00190-008-0220-2, 2008.


January 22, 2008: New tide model

New ocean model implemented (TPXO.7.1)


January 22, 2008: A short-cut   
       
A message to the frequent ocean loaders, those who find it tiresome to go through our web interface. Click here


August 19, 2007: Mass redistribution

IMPORTANT INFORMATION

To all users who engage in comparisons between model results and need most accurate loading parameters:
We have changed the Mass Redistribution policy.
It concerns stations near the coast, particularly where coastlines are complicated and tides are high.

The policy is now that

Mass redistribution due to higher coastline resolution is carried out in the cases of the hydrodynamically closed models (SCHWiderski, FES94 and FES95), and only in these cases.

Previously, mass redistribution was always carried out, i.e. also in the cases of the empirical models (based on ocean observations).

If a user recognises differences between empirical loading signals (from e.g. GPS) and the empirical models, our suggestion is to recompute the modelling results.

We gratefully acknowledge Nigel Penna for pointing this problem out to us.



February 4, 2007: Welcome to a new machine
10 times faster. FES2004 takes a few minutes per station now.



December 19, 2006 - ALTERNATIVE SITE AVAILABLE
The backup site at GEODAC , Porto, Portugal, is ready to accept requests, offering the full suite of ocean tide models.



January 2006: Centre of mass tides
CMC-files available - giving you a look under the hood of centre of mass correction. For experimental use. See the CMC page .



Previous news and bug reports:  19 Dec 2006

Hans-Georg Scherneck, Chalmers, Onsala Space Observatory
Page updated 2011-06-20