GEOPHYSICS

**Definition:** This place covers:

Methods and apparatus for geophysical purposes such as

Seismic measurements, including the generation of seismic energy, the detection of seismic signals and their processing.

Measuring the magnetic or electric field of the earth or its modification by geological structures.

Measuring the gravitational field of the earth or its modification by geological structures.

Prospecting or detecting of masses or objects in general, e.g. by seismic, electric, magnetic, gravimetric or optical means, or by the use of nuclear radiation.

Measuring gravitational fields or waves in general, e.g. gravitational forces between two bodies, or gravitational waves of cosmic origin.

Manufacturing, calibrating, cleaning, or repairing such apparatus.

Tags attached to, or associated with, an object, in order to enable detection of the object.

Geophysical modelling, whether or not related to the measurement of a physical parameter.

In this subclass, the geophysical methods apply both to the earth and to other celestial objects, e.g. planets.

**Limiting references (this place does not cover):** - Means for indicating the location of accidentally buried, e.g. snow-buried, person -> A63B29/02

**Glossary:** - tags: means arrangements cooperating with a detecting field, e.g. near field, and designed to produce a specific detectable effect; "tags" also means active markers or labels capable of generating a detectable field; tags are not to be confused with transponders (cf Glossary of G01S ) - transpondeur: means an arrangement which reacts to an incoming interrogating or detecting wave by emitting a specific answering or identifying wave.