MMA/ALMA Site on Chajnantor Plateau, Chile, November 1994
In late October and early November 1994, Peter Napier (standing), Angel Otarola (back to camera), Frazer Owen (wool hat), and Simon Radford (taking the photo) visited a possible site for the Millimeter Array on the Chilean Chajnantor plateau, the eventual site for ALMA. This photo, looking to the west and into the prevailing wind, shows equipment sheltered behind a large rock, with small wind break walls built to each side. Solar panels on the ground and batteries in the cardboard box power a 225 GHz tipping radiometer, the gray box with a handle sitting in the door of the tent. The team, here troubleshooting some difficulty with the tipping radiometer, made the first measurements of millimeter wavelength (225 GHz) atmospheric transparency on the Chajnantor plateau. These measurements gave the first indication the plateau enjoys excellent observing conditions for submm astronomy, much better than any sites previously considered for the MMA. More extensive measurements, which began in April 1995, confirmed the initial indications. The tent site is about 4 km north of the ALMA AOS building.
Records of the NRAO
Records of the NRAO, “MMA/ALMA Site on Chajnantor Plateau, Chile, November 1994,” NRAO/AUI Archives, accessed June 1, 2023, https://www.nrao.edu/archives/items/show/36680.