Geophysics

Wouldn't it be wonderful if life were like Star Trek, with sensors we could use to see what's in the ground beneath our feet in all its spleandour? Well, unfortunately we're not able to make such sophisticated sensors yet, but the science of geophysics is doing its best to work towards that goal. There are many geophysical techniques being used all over the world to make new and exciting discoveries about the subsurface, so here we will try to provide some useful information on what it's all about. Here are some geophysics articles to tell you more:

Arduino Accelerometer: Would you like to measure vibrations, or motion gestures for VR and gaming? If so, here's a simple Arduino accelerometer project, with selectable sensitivity, that can do that and more. The data can be obtained via USB to graph in a spreadsheet, or via Bluetooth into a Pocket PC program.

Arduino Magnetometer: Magnetometers are excellent devices for measuring the strength of magnetic fields, but are also expensive. To learn a bit more about magnetometers (or just for detecting metal) here we present a simple Arduino circuit to take advantage of the two magnetometer channels in an inexpensive compass module. The data can either be imported into a spreadsheet, or gathered and viewed using the Pocket PC software included here.

Electromagnetic probe modelling: Processing is not only fun, it can be used for some serious numerical modelling too. This applet models an electromagnetic testing probe, providing a 3D graphical representation of the voltage distribution along the probe when immersed in a variety of materials.

FSST 2010 TDR Paper: Time-domain reflectometry (TDR) is an excellent, and relatively simple, way to measure the apparent permittivity of soils. However, in this paper from the FSST 2010 conference it is argued that improvements are needed to it for adequate use with fine-grained soils.

Java GUI applet in Processing: Did you know that you can include native Java code and controls in Processing, and use them to create an applet for your website? In this article we do just that and create an applet to calculate radio wave velocities, from apparent permittivity values, as an example.

Soil EM history: If you're interested in, or even starting to study, soil electromagnetic properties, you may find the history of the topic equally interesting. If so, this brief guide will give you an introduction to the history prior to 1980.

Soil EM glossary: Whether you're studying soil electromagnetics, or want to understand what geophysical people are telling you, understanding basic technical terms is important. So, on this page you will find a brief glossary of some of the most important soil electromagnetic property terms.

VNA Mini PPC: Vector network analysers can be very useful for measurements of signal amplitudes and phase changes. On this page you will find details of free software written in NS Basic to allow an inexpensive Mini VNA to be used with a Pocket PC via BlueTooth.