H/V spectral ratio

This tool is used to obtain Horizontal to Vertical (H/V) spectral ratios from any type of vibration signals (ambient vibrations, earthquake…). The example used for explanations is an ambient vibration recording.

Getting ready

• Download compressed signal file.
• Load and view these downloaded signals.
• Select H/V in menu Tools (alternative ways to start a tool)

Window selection

Timing tab H/V toolbox

• Make sure you are in the Time tab, and that parameters are as in the example window.

Viewing results

The toolbox may be opened in two different ways:

• if the signal window is already open clik on the H/V icon
• if the signal window is not open drag the file(s) from the file manager to the H/V icon

The toolbox shows up in the form it was previously closed, with the file name(s) in the header.

The toolbox contains set ups for windowing selection and processing, together with output parameters.

Comprises three tabs:

Time tab

Divided into three parts

Global time range

Global time range

Used to select all or part of the signal to be processed.

Works like the Waveform/Cut basic signal processing under the Waveform menu.

When "Use only the properties of the first signal" is checked, all tracks use the time parameters (T0, End, Picks) of the top track.

Time windows

Time window paramaters of H/V toolbox

Comprises 4 tabs:

Windowing results

Below Time windows a line gives the resulting selected windows, in all stations, with possibility to get the number of windows in each station through the View pop-up menu.

Further readings

• Spectral ratios along a profile

• Mapping spectral ratios