Modal Test: Measurement and Analysis Requirements

Analysis of modal test data prior to dismantlement of the test setup is required to assure high quality data. Often erroneous or incomplete data, which are detected after the test, do seriously compromise the value of the test itself. With the advent of minicomputers for modal testing to reduce the test duration, a larger burden exists on rapid data analysis to support the test. The experiences at the Jet Propulsion Laboratory in data analysis and its presentation are described. Data analysis results from the Viking Orbiter Program are used to illustrate the analysis and its presentation.