Those two words are synonymous. They are used interchangeably in the literature. In some cases a survey might relate to a questionnaire that is distributed by different modes (paper, telephone,...
You survey land, people, things etc. out in the open. Surveillance would be done under cover or just observing something for a long period of time in the open.
Also, a survey is like a poll, a...
A census is a statistical enumeration and analysis of a certain population, be it humans, animals or plants - groups that grow and change over time. A survey can be a tally of opinions or answers....