Meanings

manned mission (e.g. space probe)

planetary probe

expedition vessel

research vessel

going out in search of plum blossoms

radio detection

direction finding

court-initiated fact discovery

looking for a room (to rent)

Russian spy (during the Russo-Japanese War)

transmission of a sonar pulse

flaw detection

(active) sonar

radar

sounding balloon

trial by hot water

fishfinder

searching for and photography at locations used as settings for anime, manga, etc.

metal detector

Society of Exploration Geophysicists of Japan