The four smaller blades are safer than a helicopter with one large main rotor. The main rotor of a helicopter is large and has a lot of inertia, so it can do more damage than several small props. It is more prone to mechanical failure than multi-rotors or airplanes due to the high vibration induced by the heavy main rotor blade.
The Pulse Aerospace Vapor 55 is capable of carrying the Riegl Vux-1 Lidar as shown below.

This is a popular set up. It weighs under the 55 lb. FAA maximum weight limit for a sUAS. The cost is several hundred thousand dollars. The price might sound steep, but it has been a very sound investment for many companies. The daily rate for the operation of one of these by a data acquisition service company can be tens of thousands of dollars depending on the circumstances.
SPECIFICATIONS
Gross Weight
Useful Load – (Battery + Payload)
Allowable Payload – With Full Endurance*
Max Cruise Endurance – With Full Payload
Max Hover Endurance – With Full Payload