surveying instrument vs surveyor's instrument

surveying instrument and surveyor's instrument both are nouns.

Word	Noun	Adjective	Verb	Adverb
surveying instrument	Yes	No	No	No
surveyor's instrument	Yes	No	No	No

As nouns, surveying instrument and surveyor's instrument are synonyms defined as:

surveying instrument and surveyor's instrument: an instrument used by surveyors

surveying instrument (noun)	surveyor's instrument (noun)
an instrument used by surveyors	an instrument used by surveyors