power inspection

Overhead line inspection is the clearest case where an aircraft pays for itself, because the alternative is a helicopter or a rope access team, and both are expensive and both create their own risk. A corridor flown with an RTK-fixed platform produces a geometrically accurate corridor model and a consistent image set, which means the same defect is photographed the same way every cycle and two surveys can be compared automatically. That repeatability is what turns inspection into a programme rather than a series of sorties. For thermal work the geometry is what makes the imagery defensible: a radiometrically calibrated thermal image co-registered with the visible orthomosaic can be compared against the previous cycle and a genuine hot spot separated from a reflection or a sun-warmed conductor. Vegetation encroachment is the other half of the job, and it is the one that creates liability, because the clearance distance is a legal threshold rather than a preference. A corridor model with a measured surface height and a vegetation surface model gives the analyst an encroachment figure in centimetres rather than an eyeball judgement. Buyers comparing platforms should look at three numbers: the horizontal accuracy of the corridor model, the minimum object size of the thermal sensor, and whether the flight plan can be re-flown automatically along the same centreline. The first decides whether the model can be used for asset records, the second decides which defects are detectable at all, and the third decides whether the comparison across cycles is actually worth doing.