What is the test for establishing "founded suspicion" in a search warrant application?

In United States v. Cortez, supra, 449 U.S. 411, 101 S.Ct. 690, the high court stressed the importance of taking into account "the totality of the circumstances" in determining the propriety of an investigative stop or temporary detention: "Courts have used a variety of terms to capture the elusive concept of what cause is sufficient to authorize police to stop a person. Terms like 'articulable reasons' and 'founded suspicion' are not self-defining; they fall short of providing clear guidance dispositive of the myriad factual situations that arise. But the essence of all that has been written is that the totality of the circumstances--the whole picture--must be taken into account. Based upon that whole picture the detaining officers must have a particularized and objective basis for suspecting the particular person stopped of criminal activity." (Id. at pp. 417-418, 101 S.Ct. at p. 695.)