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Hi, I want to analize a record with an active source MASW in geopsy, however when I load the file, traces appear but I cant to get the dispersion curves, I get the following message:

Number of selected stations is less than 2 for array 1.

In other softwares, this problem does not occur.

how I can fix this problem?

Thanks,
best regards.
pd: sorry for my english

Di you switch to "No common time reference (leave T0 as is)" in the load preferences? By default, geopsy is dedicated to absolute time records, which is not the case for such experiment. With this option, Time Reference (look at signals in a table) contains the date of acquisition (according to instrument clock) or if the information is not available in header, the file creation time.

Before proceeding to active experiment processing, Geopsy organizes all traces looking at shot coordinates and time reference. Files are not considered by Geopsy to identify shot records. Geopsy is designed to work transparently with records spread over several file or stored together with other shots. If you get such error message, there should be missing information in your header table. If still you cannot resolve it, post a snapshot of your table or choose "Export" from menu "File" applied on a table, select "Table" format and post the result.

Dear,
I got some results from ABAQUS and PLAXIS software that i save them in text file.
Text file includes some column (24) that each column represents the record of each geophone.
I cannot analyze the data and obtain F-K or dispersion curve from data by using Geopsy (MASW). In this regard, Could you possibly guide me how to adjust and write the suitable header for text file?
Thanks

Why did " Time reference" feature disappeared in newer versions? I'm having a really hard time working, features are different in older and newer versions, and it always seems to be something missing. i can do one step in one version, then the next step in the other and so on.
Specifically i am trying to do passive FK of 2 acquisitions, forming an L . But the recording happened with 2h difference between one line and the other, due to this i can't "merge" both files ( in the 3.4.1 version), though i can perfectly see it in the 2.10 version. However, when i compute FK for passive in he 2.10 version, it shows only vertical lines and not 2D "circles". If i do the FK analysis for both files separated, one shows vertical lines in X and the other vertical lines in Y, so im guessing both together should show some kind of 2D feature, but it does not.
Any ideas ? Thanks

Geopsy releases above 3.0 are using only absolute timing. If you are using synthetic signals or if absolute timing is not important for you, just choose an arbitrary time like "2000-01-01 00:00:00". You can use menu "Edit/Set header" to change the StartTime for all signals: If your two lines are recorded with two different time ranges they cannot be processed together with a FK. A FK process requires synchronous signals. The typical array response of a linear array is a pattern with straight lines perpendicular to the direction of the line (try warangps, under tab 'Map', load coordinates of linear array and a a 2D array to see the difference).

All you can do with such recordings is passive linear arrays (like REMI method) which does not reach the same performance as a 2D array. Oriented patterns in the ambient wavefield may distort the response. SPAC can also be tried with linear arrays. Having two perpendicular lines and assuming that the properties of the ambient wavefield are relatively the same for the two recordings can be a good opportunity to track biases due to oriented wavefields.

Best regards,

Marc