What is the different with "survey" and "investigation"?

survey:[ sə:'vei ] n。纵览,视察,测量v。审视,视察,通盘考虑,调查1。We stood on the top of the mountain and surveyed the countryside。我们站在山顶上,眺望乡村。2。This survey is the work of a real professional。这份调查是真正内行人做的。3。A survey of the property shows that the northern boundary is not correct。对这块地产的测量表明,它北面的边界线是不正确的。4。Follow-up survey shows that the reoccurrence rate is only 5%。跟踪调查表明复发率仅为5%。5。Only children under five are excepted from this survey。这次调查仅仅不包括五岁以下的儿童。investigation:[ inˌvesti'geiʃən ] n。调查1。The accident is under investigation。这一事故正在调查之中。2。The government made an investigation of the employment in the public and private sectors。政府对国营和私营部门的就业情况作了一次调查。3。The investigation was carried out under the direction of a senior police officer。调查是在一位高级警官的指导下进行的。4。We were greatly aided in our investigation by the cooperation of the police。我们在调查的过程中得到警方的大力协助。5。It's only the initiative of the investigation。这仅仅是调查的开始。6。He has promised a thorough investigation into the affair。他已答应彻查此事。由此,我觉得 surey是专业意义上的(比如采取问卷或者技术)。。。investigation是比较广义的说法。。。