Operations: Evaluation of photographic data to predict base~surge ef- fects from surface detonations. Photography from other projects was used, Shots: All. Radiation Exposure Potential: Slight (data for the project were from other units). Staffing: Two civilians from NOL, attached to this project, received total exposures of 0.120 R and 3.165 R. The individual receiving 3.165 R also participated in Projects l.la, 1.1b, and 1.1d, and probably did not receive significant exposure as part of this project. Project Report: Reference 42. Project 1.2a -- Ground Level Pressures from Surface Bursts Agency: Sandia Corporation Operations: (SC) Instrumentation was installed on various islands of both atolls for this project and Projects 1.3 and 1.7. Measurements for this project were obtained on blast pressure versus time at ground levels with Wiancko gauges. Shots: All. Radiation Exposure Potential: Placement of instruments in areas con- taminated by prior shots and recovery of data would have posed a po- tential moderate exposure. Staffing: Two civilians from SC were associated with this project; they had total readings of 1.315 R and 1.195 R, but also participated in Project 1.3. Project Report: Reference 43. Project 1.2b -- Ground Surface Air Pressure versus Distance from High-Yield Detonations Agencies: Ballistic Research Laboratories (BRL) 930lst Test Support Unit, Aberdeen Proving Ground 172