What physics do we need?

Before we talk about streamers, vibroseis trucks, or ocean-bottom nodes, we need a shared vocabulary for the physics that sits under every design choice. This opening section is a map — not a lecture.

The interactive widget below has two columns. On the left are the nine pieces of physics covered in §0.2–§0.10. On the right are the acquisition design outcomes those physics pieces directly feed. The edges between them say: “to decide this, you need this piece of physics.”

How to use the map

Hover any physics node on the left to see which design decisions depend on it. Hover any design outcome on the right to see which physics it is grounded in. Click any node to jump straight to its section.

The three groups of physics

• Wave physics (§0.2, §0.3, §0.4, §0.10) — how energy radiates from a source, reflects at interfaces, and attenuates as it propagates. This controls what you can detect.
• Array & sampling (§0.5, §0.6) — how multiple sources or receivers combine, and how finite sampling in time and space constrains the signals you can faithfully record. This controls what your geometry must look like.
• Noise & statistics (§0.7, §0.8, §0.9) — what counts as signal, what counts as noise, and what invariants of your experiment you can exploit. This controls what your fold and stack must deliver.

Throughout the rest of this textbook we will reach back into this map. Every time a design choice seems to come from nowhere — “why 25 m bins?”, “why 12 guns in the array?”, “why that streamer length?” — the edge in the map points to the physics section that answers it.

Design physics vs processing physics

Seasoned students sometimes ask whether this primer overlaps with the Processing textbook’s Part 0. The answer is no. Processing’s Part 0 teaches the math you need to reason about recorded data: convolution, Fourier, Z-transforms, least squares. Acquisition’s Part 0 teaches the physics you need to design the experiment that produces that data: how an air-gun bubble oscillates, why geophones have a natural frequency, how antenna theory constrains a source array’s directivity. The two books are complementary; if you are going to plan surveys, you need both.

When you are ready, click through to §0.2 to start with wavefronts and rays — or use the map below to jump to any physics topic that interests you first.

References

• Sheriff, R. E., Geldart, L. P. (1995). Exploration Seismology (2nd ed.). Cambridge University Press.
• Yilmaz, Ö. (2001). Seismic Data Analysis: Processing, Inversion, and Interpretation of Seismic Data (2 vols.). SEG Investigations in Geophysics 10.
• Liner, C. L. (2016). Elements of 3D Seismology (3rd ed.). SEG.
• Bracewell, R. N. (1999). The Fourier Transform and Its Applications (3rd ed.). McGraw-Hill.