Unmanned Aerial Systems for Magnetic Survey

Abstract

Placing a magnetometer on unmanned aerial vehicle (UAV) seems to be an easy task as the sensor is rather lightweight in comparison with other geophysical sensors. But, the realization of an unmanned aeromagnetic system (UAMS) faces multiple technical complications, and, as a result, very few of many attempts to build a UAMS have succeeded. Even less projects have produced results of real magnetic survey. Different platforms (helicopters, multirotor, and fixed wing UAVs) and different kinds of magnetometers for UAMS have different pros and cons for the purpose. For the quality of magnetic survey, the most important is the issue of a platform's (UAV) magnetic noise and its influence on a magnetic sensor. Workbench experimental studies as well as results of magnetic surveys with multirotor UAMS in Leningrad region, Republic Sakha-Yakutia, and Kazakhstan demonstrate solutions facilitating state-of-the-art high-quality measurements of magnetic anomalies for geological, archeological, and other purposes.

Cooperative digital magnetic‐elevation maps by small autonomous aerial robots

“…In the recent work of Cherkasov and Kapshtan (2018), a set of aeromagnetic surveys measured the total magnetic intensity in different regions of Russia and Kazakhstan. The authors discussed the applicability of multirotor or fixed-wing UAVs, and several magnetometer models were considered to be used with those platforms.…”

Magnetic interference mapping of four types of unmanned aircraft systems intended for aeromagnetic surveying

“…Unmanned aircraft systems (UAS) are being used as an alternative method for traditional ground geomagnetic surveys on the scale of <1km 2 (Eck and Imbach, 2012;Macharet et al, 2016;Parshin et al, 2018;Parvar et al, 2018;Versteeg et al, 2010), <10km 2 (Kaneko et al, 2011;Koyama et al, 2013;Malehmir et al, 2017;Wood et al, 2016), and larger 25 (Anderson and Pita, 2005;Cherkasov and Kapshtan, 2018;Funaki et al, 2014;Pei et al, 2017;Wenjie, 2014). Their ability to fly along tightly-spaced lines at low altitudes produces a higher resolution map than those produced by typical manned aeromagnetic surveys.…”

Characterization and compensation of magnetic interference resulting from unmanned aircraft systems

“…Unmanned aircraft systems (UAS) are being hailed as a replacement for traditional ground surveys (Parshin et al 2018) and are being used to perform geomagnetic surveys on the scale of <1 km 2 (Versteeg et al 2010;Eck and Imbach 2012;Macharet et al 2016;Parshin et al 2018;Parvar et al 2018), <10 km 2 (Kaneko et al 2011;Koyama et al 2013;Wood et al 2016;Malehmir et al 2017), and larger (Anderson and Pita 2005;Funaki et al 2014;Wenjie 2014;Pei et al 2017;Cherkasov and Kapshtan 2018). Their ability to fly along tightly-spaced lines at low-altitudes produces higher-resolution maps than those produced by typical manned aeromagnetic surveys.…”

“…In hardware, a straightforward approach is to increase the magnetometer-UAS separation. One method has been to tow the magnetometer below the UAS at a distance where the interference becomes negligible; often reported as >3 m (Koyama et al 2013;Malehmir et al 2017;Cherkasov and Kapshtan 2018;Parvar et al 2018;Walter et al 2018). This can introduce new issues such as heading and location error (Walter et al 2016), reduced flight stability, increased drag, and increased risk of impact damage to the magnetometer upon landing (Kaneko et al 2011).…”

“…This activity will help to locate areas of low interference and inform magnetometer placement. The results of several magnetic interference investigations have been published(Versteeg et al 2007(Versteeg et al , 2010Forrester 2011;Kaneko et al 2011;Sterligov and Cherkasov 2016;Cherkasov and Kapshtan 2018;Parvar et al 2018) but only a few include a detailed methodology for mapping the UAS.Forrester(2011)mapped a 95 kg gas-powered fixed-wing UAS using a hand-held uniaxial fluxgate magnetometer and identified three interference contributors in order of severity: the servo(s) (50-100 nT at 0.55 m), the engine and engine assembly (60 nT at 0.55 m), and the avionics package (30 nT at 0.38 m). The method described by Forrester (2011) included rigorous testing of each component individually.…”