UAVs have been deployed increasingly to collect magnetic data, however acquisition using these systems often lack QAQC checks that are typically expected from fixed-wing or helicopter-based acquisition. Furthermore, survey parameters such as line spacing or mean terrain clearance are often not given enough thought given the higher noise levels typically associated with this style of acquisition. UAVs are not immune to system noise, instrument noise, GPS or navigation issues that also arise in their larger, fixed-wing and helicopter counterparts and these need to be addressed prior to acquisition. Due to the commercial infancy of these systems, delivered products are often suboptimal as they lack contractual agreements of data quality and noise levels. Factors such as deviation from planned survey height, deviation from planned lines, noise levels above a threshold etc. need to be pre-agreed on in a way that is fair and transparent to both the UAV operator, as well as the client. Processing of UAV data can be thought of in two stages; the first being spatial data processing - checking and correcting for GPS positioning errors, including altitude, and separating the data into individual lines resulting in a correctly located neatly trimmed data set. The second stage is the assessment and correction of magnetic data - removal of spikes, dropouts, diurnal base station correction etc. UAV data tends to be delivered as grids, images, and ASCII line data which oftentimes, has undergone minimum processing in this two-stage process. These data require additional processing to correct artifacts in the data related to line-directionality and height variations to allowing the gridding of a clean magnetic image without removing geological information.

Open-Access Online Publication: March 01, 2023