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Welcome to the free ocean tide loading provider

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IMPORTANT: A Code of Good Conduct - please read carefully.

March 11, 2022: Extended parsing of requests
A more thorough parsing of station records has been enacted. Requests that fail the test will not be processed.
Instead, the system sends a notification back to the user with hopefully useful advice.

February 03, 2022: New model TPXO.9.5a
This is a 1/61/6 degree model, an update of TPXO.9.2a

December 2021: Stricter coding requirements for direct email
If you bypass the web page and instead send your requests by email, we refer to updated instructions as users had been experiencing denial of service.

April 25, 2021: New model EOT20
(Hart-Davis et al., DGFI, doi=10.17882/79489)
July 12, 2021: Problems have been found recently. A revised version has been installed today at 10:00 UTC. Please resend your requests issued before this date.

August 9, 2020: Error in GOT4.10c with centre of mass option
Tides Q1 and K2 had erroneous coefficients for centre of mass.
Please resubmit your sites if you have used this combination of options.

June 26, 2020: New model TPXO.9.2a

March 7, 2020: Error in our copies of GOT4.10c, Q1 and K2 amplitudes, corrected.
For high-precision applications, the set of loading coefficients should be recomputed.

January 6, 2019: New model TPXO.9-Atlas
A high-resolution model, 30x30 cells per square-degree. Loading jobs are carried out at SEGAL at UBI/IDL inPortugal.
February 05, 2018: Alternative loading Greens function available
For decades the load convolution used an elastic Greens function based on the Gutenberg-Bullen earth model. You can choose an alternative, a Green's function for an anelastic Earth [...] . Further reading: Bos and Scherneck (2013)
February 05, 2018: A pro-memoriam on BLQ files (updated)
with emphasis on phase and its conversion for reckoning with respect to the local solid earth tide.
February 05, 2018: Revision of service for gravity and tilt
Today the service goes official with tilt parameters [...].
February 05, 2018: Revised version of converter script
for BLQ to TSOFT and g-Software (Micro'g Lacoste), [...]

(old news)


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, 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-format 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. Note: Default model is a fake to bar spammers

What type of loading phenomenon do you consider
vertical and horizontal displacements
gravity (nm/s2) and tilt (nrad)

using Greens function
elastic (Farrell, 1972)
visco-elastic (STW105)

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.)
The coefficients are available here.
Do you want to correct your loading values for the motion?

Want a plot?   Option is available for the ocean models with a grid constant ≥ (1/8)o
The plots show the grid refinement in the near-field and also the resolution of the coastline.
They are generated for each site that involves the loading post-processor. Notice "Computed by OLMPP" in the result file.

Fetch plot here  after you received the results. Look for your user name: name-olmpp1.png name-olmpp2.png etc.
Also see the Caption common to all maps.

What kind of output format is required?

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

Where are your stations? 
In the following form, up to one hundred stations can be entered, each station on a separate line.
In the case of displacements, the height of the station above sea level is irrelevant; it is not necessary to specify this parameter at all.

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

Our fixed column layout:  Show example
No blankspace to the left.
24 characters for the station, 25'th column blank, then three numerical fields with a width of 16 characters each, no TAB characters please! Each value MUST carry one floating-point dot followed by at least one decimal, but three decimal places (case XYZ) or five (case degrees) are more than sufficient.
On a UNIX/Linux system you can produce station lines for copy-and-paste with
printf "%-24s  %15.3f %15.3f %15.3f\n" $name $x $y $z
printf "%-24s  %15.5f %15.5f %15.3f\n" $name $lon $lat $hgt

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.

Drift messages, planned outages of service

No reply?
Start with a look at the page listing jobs in waiting, forwarded to the Cloud-based service, in process, and completed at the OSO site. If you don't find your job there or if you don't get a reply within a few hours, please have a look at our why-not criteria and (un-)common errors and check that you have supplied a correct email address.
If you find your request with the remark "Forward to Cloud", it might have got stuck in the relay. Send a note to Hans-Georg Scherneck, and we will clear up the situation. The hints below will not apply.

NEW  If your email address was faulty, download the result file instead: A limited number of files, at least 10, is stored here.
If you don't find the result file, something went wrong while any diagnostics ended up in limbo. Then resubmit with a correct email address.
Your job may be in the queue. Have a look here, the page is updated every minute.
If you don't find your username on this page, your email address may be blacklisted. Here is what to do.

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: Nov 22, 2022

Send comments or questions to Hans-Georg Scherneck,
Don't send them to
---the system trashes anything but ocean loading requests after strictly parsing the filled-in form.