Angle Range & AVO Adequacy Check

Calculate seismic reflection angle coverage from acquisition geometry. Assess whether your data provides adequate angle range for meaningful AVO analysis. Critical quality control before interpreting amplitude anomalies.

Acquisition AVO QC Angle Gather Offset

Input Parameters

Target Depth

m
Vertical depth to reservoir
m/s
For time-depth conversion

Acquisition Geometry

m
Minimum source-receiver distance
m
Maximum source-receiver distance
m

AVO Analysis Requirements

degrees
Recommended: 0-5°
degrees
Recommended: 30-40°

Results

Theory & Guidelines

Angle Coverage Requirements

For reliable AVO analysis:

  • Near angles (0-10°): Essential for intercept measurement
  • Mid angles (10-25°): Transition zone, gradient emerges
  • Far angles (25-40°): Critical for gradient and class identification
  • Avoid >45°: Approximations break down, noise increases

Minimum recommendation: 0-30° coverage with <5° gaps

Angle Calculation

Reflection angle from offset and depth:

θ = arcsin(offset / (2 × √(depth² + (offset/2)²)))

Key factors:

  • Deeper targets → narrower angle range for same offsets
  • Longer offsets → larger maximum angles
  • Near offset → controls minimum angle coverage