Force planes equipped for cloud sampling and tracking were available and were on call. Arrangements were made for the use of another special aircraft for radiological monitoring surveying at H + 24 hours. Mobile Ground Monitoring Mobile ground monitoring teams were deployed in the downwind sector prior to each test to supplement the routine surveillance which was a part of the continuous surveillance program. The downwind sector was determined by information obtained from the U. S. Weather Bureau personnel assigned to the NIS. These monitoring teams consisted of two men. Each team was equipped with beta-gamma survey instruments, chamber survey instruments, fallout trays and additional air samplers and recorders. Each vehicle was equipped with two-way voice radio communication. The number of teams used for each event was determined in advance by the predicted radiclogical situation, however five to ten teams was number deployed. the usual Up to 20 teams could be organized within a short time, but were not normally maintained on a stand-by basis. Air Sampling There were thirty permanent air sampling stations in operation 24 hours per day in the area surrounding the NIS at distances up to 180 miles distance. (Graphics No. 9) The air samplers used were high volume motors, drawing air through an 8" x 10" glass fiber filter. When deemed desirable, a secondary activated charcoal cartridge is added for the collection of gaseous fission products. Flow rates were approximately 50 cubic feet per minute (cfm) for the glass fiber filter alone and 25 cfm with the charcoal cartridge added. Glass fiber filters were counted for gross beta activity in the proportional region.