Cases & packages

Each package contains a description of the technique for solving some problem in marine geophysical engineering research. The package includes:

documentation describing the problem and the solution method;
script code and functions implementing mathematical processing, if it is necessary for solving the problem;
geophysical survey data that are used to run the script and quickly try out the technique.

Each technique is implemented as a "brick" that can be used to build a geophysical survey process as efficient as possible and free of hidden errors.
The script execution requires installation of GNU Ostave or MatLab. The package contains all the necessary functions to run the script. The versions of the functions correspond to the time the package was created; the latest versions of the functions are contained in the ge0mlib library.

Streamer coordinates (HR/UHR)

Package C05_03. Magnetometer synchronisation (ScanFish)

Delays in the ScanFish-QINSy data transmission channel introduce an additional type of measurement inaccuracy associated with the measurement time-referencing errors (synchronisation errors). The artefacts arising due to synchronisation errors are clearly visible as a "saw effect" (high-frequency meander) in the magnetic field gradient plots (the difference between the readings of two magnetic sensors).

The package provides with the method of applying corrections for time delays in magnetometer records and removing "saw effect".

C05_03_MagT14 pack_r02.7z
(C) 2024-2025 N-Sea Offshore B.V.

Package C02_06. Z correction (SBP)

The "SES Convert Version 2.3.4.0" file converter (and its earlier versions) does not correctly apply Z corrections to Innomar files with *.ses3 extension. This package was originally created to apply Z corrections properly.

The script allows you to perform the following actions:

apply Z corrections from text files to seg-y files;
apply a shift for "Delay Recording Time" (range correction) to the seismic section;
select a seismic section to view in the SBP track-plot;
view a seismic section with "MBES seafloor" (interpolation of coordinates from pts-file to seismic trace coordinates), while simultaneously viewing MBES data; it is possible to set the sound speed for each SBP section, which affects the position of the seafloor.

C02_06_Sbp02 pack_r03.7z
(C) 2025 N-Sea Offshore B.V.

Package C04_08. Navigation injection in JSF files (SSS)

Incorrect application of the SSS heading and the "Time constant for course smoothing" parameter in SonarWiz can result in a shift of up to several metres in the target coordinates in the sonogram (see C04_07_Improvement SSS positioning accuracy_rev1.0.pdf).
The package presents a case of injecting coordinates directly into JSF-files, for loading into SonarWiz without using NavInjector utility and with zero value of "Time constant for course smoothing" parameter.

Under development

Package C03_04. Positioning of streamer receivers by direct wave travel time (HR/UHR)

When performing engineering surveys with HR/UHR methods, the following positioning system is often used: GPS receivers are installed on the seismic source and tail buoy, the lead buoy is absent, and the seismic streamer is considered as a thin thread stretched from the tow point to the tail buoy. The coordinates of seismic receivers are determined with a relatively large error, since the dynamics of the movement of the streamer in the water column differs from the movement of a thin thread stretched in the air.

The package implements a technique for more accurate positioning of the first receivers, which is based on using the travel time of the direct wave from the source to the receivers. The script allows you to prepare files P1/90 format that contain:

coordinates and water depth for the nodes (streamer tow point, seismic source, tail buoy);
coordinates of seismic receivers (hydrophone groups) corrected for direct wave travel time, as well as depth of receivers calculated from depth controller data.

Publication under approval
(C) 2025 ROMONA Inc.

Cases & packages Each package contains a description of the technique for solving some problem in marine geophysical engineering research. The package includes: documentation describing the problem and the solution method; script code and functions implementing mathematical processing, if it is necessary for solving the problem; geophysical survey data that are used to run the script and quickly try out the technique. Each technique is implemented as a "brick" that can be used to build a geophysical survey process as efficient as possible and free of hidden errors. The script execution requires installation of GNU Ostave or MatLab. The package contains all the necessary functions to run the script. The versions of the functions correspond to the time the package was created; the latest versions of the functions are contained in the ge0mlib library.	C05_03 Mag sync (ScanFish) C02_06 Z correction (SBP) C04_08 Nav injection (SSS) C03_04 Streamer coordinates (HR/UHR)
Package C05_03. Magnetometer synchronisation (ScanFish) Delays in the ScanFish-QINSy data transmission channel introduce an additional type of measurement inaccuracy associated with the measurement time-referencing errors (synchronisation errors). The artefacts arising due to synchronisation errors are clearly visible as a "saw effect" (high-frequency meander) in the magnetic field gradient plots (the difference between the readings of two magnetic sensors). The package provides with the method of applying corrections for time delays in magnetometer records and removing "saw effect". C05_03_MagT14 pack_r02.7z (C) 2024-2025 N-Sea Offshore B.V.
Package C02_06. Z correction (SBP) The "SES Convert Version 2.3.4.0" file converter (and its earlier versions) does not correctly apply Z corrections to Innomar files with *.ses3 extension. This package was originally created to apply Z corrections properly. The script allows you to perform the following actions: apply Z corrections from text files to seg-y files; apply a shift for "Delay Recording Time" (range correction) to the seismic section; select a seismic section to view in the SBP track-plot; view a seismic section with "MBES seafloor" (interpolation of coordinates from pts-file to seismic trace coordinates), while simultaneously viewing MBES data; it is possible to set the sound speed for each SBP section, which affects the position of the seafloor. C02_06_Sbp02 pack_r03.7z (C) 2025 N-Sea Offshore B.V.
Package C04_08. Navigation injection in JSF files (SSS) Incorrect application of the SSS heading and the "Time constant for course smoothing" parameter in SonarWiz can result in a shift of up to several metres in the target coordinates in the sonogram (see C04_07_Improvement SSS positioning accuracy_rev1.0.pdf). The package presents a case of injecting coordinates directly into JSF-files, for loading into SonarWiz without using NavInjector utility and with zero value of "Time constant for course smoothing" parameter. Under development
Package C03_04. Positioning of streamer receivers by direct wave travel time (HR/UHR) When performing engineering surveys with HR/UHR methods, the following positioning system is often used: GPS receivers are installed on the seismic source and tail buoy, the lead buoy is absent, and the seismic streamer is considered as a thin thread stretched from the tow point to the tail buoy. The coordinates of seismic receivers are determined with a relatively large error, since the dynamics of the movement of the streamer in the water column differs from the movement of a thin thread stretched in the air. The package implements a technique for more accurate positioning of the first receivers, which is based on using the travel time of the direct wave from the source to the receivers. The script allows you to prepare files P1/90 format that contain: coordinates and water depth for the nodes (streamer tow point, seismic source, tail buoy); coordinates of seismic receivers (hydrophone groups) corrected for direct wave travel time, as well as depth of receivers calculated from depth controller data. Publication under approval (C) 2025 ROMONA Inc.
2015-2025