
Old Lunar Data Gets New Life, with Help from Seismologists - sohkamyung
https://spectrum.ieee.org/tech-talk/aerospace/space-flight/old-lunar-data-gets-new-life-with-help-from-seismologists
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mturmon
Abstract from a presentation by Ceri Nunn at last year's AGU meeting
([https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/239675](https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/239675)):

"As a part of the Apollo lunar missions, five seismometers were deployed on
the near side of the Moon between 1969 and 1972, and four of them operated
continuously until 1977. Seismic data were collected on the Moon and
telemetered to Earth. The data were recorded on digital magnetic tapes, with
timestamps representing the time of signal reception on Earth. The taped data
have been widely used for many applications. Data from the tapes had also been
transferred to SEED (Standard for the Exchange of Earthquake Data) format and
these SEED files were previously available at IRIS (Incorporated Research
Institutions for Seismology). However, there were some timing-related problems
with the original SEED files. We have re-imported the long period data to SEED
format, and will make these data available via IRIS. There are many gaps
within the data caused by loss of signal or instrument problems. The signal is
reconstructed to be read in as a continuous record, with gaps within the
seismic trace where necessary. We also record the ground station which
received the signal from the Moon, and we preserve the timestamps within the
file. The timestamps indicate that the sampling rate varies by up to 0.01 %.
We investigate how much this is a change in the apparent sampling rate (due to
the orbital parameters of the Moon and the rotation of the Earth) and how much
is due to the instrument not maintaining a constant sampling rate. We also
provide response files. The new files will be a valuable resource for
analyzing the structure of the Moon."

