I have been searching but cannot seem to find it. I would like to know what the surface gravity of Venus has been observed to be from different missions/probes that were sent to Venus on separate occasions. There have been many missions to Venus, but I can not seem to find any information regarding the measured surface gravity of this planet beyond the Magellan mission. Does anyone happen to know if Venus' surface gravity has been observed outside of Magellan and can give me a source for it?
Update: I am looking for probed observational results instead of derivations using existing calculations.