This module addresses what is an airborne gravity system. The module starts with a reference to gravity variation and acceleration. It takes you through the different types of gravity systems. Simply, there are two types of highly sensitive accelerometers used to measure the earth’s gravity field. The instruments and the calibration required are discussed. The module concludes with applications when airborne gravity surveys are appropriate, [...]
There are several standard corrections that are applied to any gravity data set. The module starts with a summary on what is a gravity system and a description of the two main types: absolute and relative. We review how gravity can measure density and/or structural variations. That leads you the main objective of the module which is to discuss the different standard gravity corrections that are applied to all gravity data sets: the theoretical ellipsoidal gravity (latitude correction), atmospheric effect, height (Free Air) correction, and terrain effects (Bouguer correction). And continue through the additional gravity corrections that are applied specifically to airborne surveys: the Eötvös correction and removing of the aircraft motion.
What should quality control procedures do? They should ultimately check for errors or conditions that are known to cause deterioration in the data quality. They should identify any processing errors, and quantify noise levels and resolution to ensure they meet contract specifications. This module delineates quality control techniques. Note that each gravity system will have its own set of quality control parameter guidelines, and the quality control check used must be specific to the gravity system being used.