Mass has a law for surveyors that makes it legal for us to trespass on other than our client's property. we just have to give them notification that we are doing it in advance.
granted most police won't enforce it if the neighbor protests by say,...Sitting on the Fucking Wall Corner that has a nice Drill Hole in it that you want to locate for your control survey (happened) but in the instance of drone work for location/topographic survey , i'd post a hanger a few days before the flight/survey on the neighbor's door.
This notice is to inform you that between xxx and yyy date we are going to be performing a survey of the land for an adjacent property. According to MGL part 4 title 1 chapter 266 section 120c. we might need to enter onto your property to acertain the location of the property boundaries and topographic nature of the land. this is your notice of the fact that we may have to enter onto your property.
The pertinent laws:
malegislature.gov
"Whenever a land surveyor registered under chapter one hundred and twelve deems it reasonably necessary to enter upon adjoining lands to make surveys of any description included under ''Practice of land surveying'', as defined in section eighty-one D of said chapter one hundred and twelve, for any private person, excluding any public authority, public utility or railroad, the land surveyor or his authorized agents or employees may, after reasonable notice, enter upon lands, waters and premises, not including buildings, in the commonwealth, within a reasonable distance from the property line of the land being surveyed, and such entry shall not be deemed a trespass. Nothing in this act shall relieve a land surveyor of liability for damage caused by entry to adjoining property, by himself or his agents or employees. "
definition of "practice of land surveying:
malegislature.gov
''Practice of land surveying'', any service or work, the adequate performance of which involves the application of special knowledge of the principles of mathematics, the related physical and applied sciences, and the relevant requirements of law for adequate evidence to the act of measuring and locating lines, angles, elevations, natural and manmade features in the air, on the surface of the earth, within underground workings, and on the beds of bodies of water for the purpose of determining areas and volumes, for the monumenting of property boundaries, for locating or relocating any of the fixed works embraced within the practice of civil engineering, and for the platting, and layout of lands and subdivisions thereof, including the topography, alignment and grades of streets, and for the preparation and perpetuation of maps, record plats, field note records and property descriptions that represent these surveys.
if they bitch, they bitch, but we have followed the law and now are not guilty of trespass for any surveying work performed (of any nature including drone since the definition includes topography