Quadrocopter support in excavation

German solution – Microdrones

The machine tested in a remote area in Russia called  Tuekta was
a „quadrocopter”: the battery-powered Microdrone md4-200.
The fact it is small – the axis of its rotors is about 27 inches
(70 cm) – and weighs about 35 ounces (1,000 grams) made it easy
to transport, and researchers said it was very easy to fly,
stabilizing itself constantly and keeping at a given height
and position unless ordered to do otherwise. The engine also
generated almost no vibrations, they added, so that photographs
taken  from the camera mounted under it were sharp.

http://www.microdrones.com

Price about: £18,000 for the full second hand system (not cheap!)

British solution – ArduCopter

Arducopter is an easy to use  multirotor / helicopter UAV.
Arducopter is based on the ArduPilot Mega autopilot created by
the DIYdrones community.  Arducopter is a complete UAV solution
that sets it apart from traditional multirotors which often only
support remote control.  The Arducopter system features fully
autonomous way-point based flight, with mission planning and
real time telemetry via the powerful ground control station.

http://www.arducopter.co.uk

Price about: $1,000

Sale offers: http://www.unmannedtechshop.co.uk