Calibration Menu

This menu facilitates access to all the tools required for calibrating airborne gamma-ray spectrometers:

• Stripping Ratios – processes data acquired over concrete calibration pads to estimate stripping ratios;
• Height Attn Coeffs and Sensitivities – analyses lines acquired over a calibration range to estimate height attenuation coefficients and window sensitivities;
• Aircraft and Cosmic Background – calculates the calibration coefficients (and spectra) required for estimating the aircraft and cosmic backgrounds; 
• Radon Stripping – Over-Water – analyses lines acquired over water to obtain a radon spectrum to calculate radon stripping ratios, as well as the c1 coefficient for the Spectral-Ratio method used for estimating radon background;
• Radon Stripping – Test-Lines – analyses the daily test lines (a short line flown at the start and end of each day) to obtain a radon spectrum to calculate radon stripping ratios, as well as the c1 coefficient for the Spectral-Ratio method used for estimating radon background;
• Spectral-Ratio c2 – estimates the Spectra-Ratio method's c2 coefficient using either offshore-onshore line pairs, or survey data using an along-line differencing technique;
• Upward-Detector a1, a2 – estimates the Upward-Detector method's a1 and a2 coefficients coefficient using either offshore-onshore line pairs, or survey data using an along-line differencing technique.

See Technical Note 2: Gamma-Ray Calibration And Data Processing for a description of the data processing steps (and calibration requirements) required for airborne gamma-ray spectrometry. The table at the end of the Technical Note summarises the calibration constants that are estimated using each of the calibration tools.