stations, station, records, system, record, equipment, data, network, instruments, sensitivity, recordings, readings, surveys, survey, needle, exploration, studies, methods, observations, work, networks, instrument, observatories, crew, systems, method, measurements, observation, recording, apparatus, reading, tests, chart, delicacy, instrumentation, accuracy, shocks, evidence, precision, disturbances, analysis, activity, operating, intuition, charts, operation, observatory, disturbance, registration, phenomena, crews, recorders, shock, devices, array, quality, maps, mass, tracings, sensibility