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Welcome to the free ocean tide loading provider

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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.


NEWS    (old news)


May 7, 2014: New tide model: OSU12

July 20, 2012: Time series from BLQ-files -  Program ttimm

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

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.


July 26, 2011: BLQ to TSOFT and g-Software (Micro'g Lacoste) converter. 
We offer a converter script olgt.pl (in perl v.5.8.8). To run it under MS Windows, read here.
Please issue  olgt.pl -h  for usage.

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.

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)


was necessary in order to keep XYZ and Lon Lat H consistent throughout the different stages of the process.

Grids
Those who need gridded ocean loading coefficients, please contact me at   hgs kanelbulle chalmers dot se
You may like to visit the Ocean Loading Grids site before.


Introduction

With the growing number of precise geodetic observations, the requests for ocean tide loading values have increased considerably. Therefore, this webpage has been created in the hope it will help the geodetic community. Just select an ocean tide model, tick the required type of loading, fill in the coordinates of the stations, give your e-mail address and press the submit button. The program will check if it can read your input and if so, it will calculate the values and send the results to you by e-mail. The program will take about 5 minutes per station. An example of the output in normal BLQ-formal can be found here while an example of the output in the new HARPOS-format can be found here .

If you find it tiresome to go through our web interface, you can send email to the loading provider in a special format.




Select ocean tide model

A brief description of the ocean tide models can be found here.


What type of loading phenomenon do you consider
vertical and horizontal displacements
gravity μm/s2
gravity mgal


If you have selected vertical and horizontal displacements, you can correct for the centre of mass motion of the Earth due to the ocean tides . ( NO   means your frame origin is in the solid earth centre, YES  that it is in the joint mass centre of solid earth and ocean.)
Do you want to correct your loading values for the motion?
NO
YES

Want a plot? (New feature of Sep. 4, 2011)
The plots show the near-field resolution of the coastline. They are generated for each site that involves the loading post-processor OLMPP. Compare with the comment information in the result file.
NO
YES
Fetch it here after you received the results. Look for your user name: name-olmpp1.png name-olmpp2.png etc.

What kind of output format is required?
 BLQ (normal) 
HARPOS (... RECENTLY ADDED FEATURE ...) 

Gravity loading parameters for TSOFT and g-Software can be converted from BLQ with olgt.pl

Where are your stations? 
In the following form up to one hundred stations can be entered but each station should be on a separate line. The height of the station above sea level is irrelevant for ocean tide load modelling of displacements: it is not necessary to input this parameter, it can be safely omitted.





Name of station_________| |Longitude (deg) | Latitude (deg) | Height (m)     OR
Name of station_________| X (m) Y (m) Z (m)


(Our fixed column layout: 24 characters for the station, 25'th column blank, then three numerical fields with a width of 16 characters each, no TAB characters please!)


What is your e-mail address?

Note: Because of a large amount of misuse we deny requests with return addresses at a couple of notorious domains.





No reply?
If you do not get a reply within a few hours, please have a look at our collection of undeliverable mail (it should work again) and
check that you have supplied a correct email-address.
Your job may be in the queue. Have a look here, it's updated every minute.
If you find the results useful, please cite this website mentioning the names M.S. Bos and H.-G. Scherneck. 

The 20-m VLBI telescope

Last updated: July 27, 2011
Send comments or questions to Hans-Georg Scherneck, hgs kanelbulle chalmers.se