This came to mind from reading "Combined line trimmer and metal detector." Metal detectors are manually operated, for treasure hunting and possibly for finding landmines (older ones that contain metal). A low-flying drone with a metal detector could scan an area, and record and/or send data on where metal is found.
-- benbradley, Sep 15 2020

Music would be preferable to a steady drone, shirley.
-- whatrock, Sep 15 2020


Combined metal detector and bagpipes ?

The horror ... the horror ...
-- 8th of 7, Sep 15 2020


You could have the "detection" sound instead vary the note of the bagpipe drones (changing the length?), so your tune rises as you approach metal.
-- neutrinos_shadow, Sep 15 2020



random, halfbakery