Close at hand and Up on

Close at hand adjective - Close in space; within reach.

Up on and close at hand are semantically related. In some cases you can use "Up on" instead an adverb phrase "Close at hand".

Up on adjective - Being up to particular standard or level especially in being up to date in knowledge.

Close at hand and up on are semantically related. Sometimes you can use "Close at hand" instead an adverb "Up on".