body-of-secrets-anatomy-of-the-ultra-secret-national-security-agency-2002

Miguel in the Philippines. Other medium-range signals could besnatched by the large NSA listening posts at Davis Station in Saigon andat Phu Bai, near the DMZ. But to snare short-range signals, such aswalkie-talkie and coastal communications, the antennas and receiverswould have to get close to the action. Off limits were the largeeavesdropping factories owned exclusively by NSA, such as the USSOxford. And far in the future were the smaller, Navy-owned Sigint ships,such as the Pueblo.The only alternative was to build Sigint shacks inside large steelantenna-sprouting boxes. These shipping-container-like huts would thenbe lowered onto a destroyer and sealed to the deck. The ship would thencruise close to a shoreline, like a spy at a party with a bugged olive in hismartini glass.They were far from ideal. Unlike the dedicated Sigint ships, whichwere virtually unarmed and unthreatening in appearance, the heavilyarmed destroyers were designed to be threatening and their presence wasprovocative. At the same time, the amount of signals intelligence thatcould be collected in the steel box on the deck was minuscule comparedwith what the dedicated ships could gather.The Naval Security Group began conducting these Sigint patrols,codenamed DeSoto, in April 1962 with missions off China and NorthKorea. In January 1964, as they were planning the OPLAN 34A hit-andrunoperations, the Joint Chiefs ordered additional DeSoto patrols off theNorth Vietnamese coast, in the Gulf of Tonkin. The signals generated bythe surprise coastal attacks, they assumed, would be a good source ofnaval intelligence for the Sigint collectors. In addition to voicecommunications, the locations and technical details of coastal radarsystems could be captured.The first mission was conducted by the USS Craig in late February1964. Resting on the ship's deck were both a Comint van forcommunications intelligence and an Elint van for radar signals. Butupon spotting an American warship idling suspiciously a half-dozenmiles off their coast, the security-conscious North Vietnamese navyquickly switched off virtually all nonessential radar and communicationssystems. Thus the Sigint take was poor.At the request of U.S. officials in Saigon who were planning the raidsinto North Vietnam, another DeSoto mission was scheduled for the endof July 1964. It was felt that if a DeSoto mission coincided with coastalcommando raids, there would be less chance of another washout.Chosen to host the electronic spies was the USS Maddox, a standardNavy "tin can," as destroyers were known. But whereas other ships hadbeen ordered to stay at least thirteen miles off the coasts of suchcountries as China, North Korea, and the Soviet Union, the Maddox was253