Seismic observations involve signals that can be easily masked by noise
injection. For InSight, NASA's lander on Mars, the atmosphere is a
significant noise contributor for two thirds of a Martian day, and while
the noise is below that seen at even the quietest sites on Earth, the
amplitude of seismic signals on Mars is also considerably lower
requiring an understanding and quantification of environmental injection
at unprecedented levels. Mars' ground and atmosphere provide a
continuous coupled seismic system, and although atmospheric functions
are of distinct origins, the superposition of these noise contributions
is poorly understood, making separation a challenging task. We present a
novel method for partitioning the observed signal into seismic and
environmental contributions. Pressure and wind fluctuations are shown to
exhibit temporal cross-frequency coupling across multiple bands,
injecting noise that is neither random nor coherent. We investigate this
through comodulation, quantifying the signal synchrony in seismic
motion, wind and pressure. By working in the time-frequency domain, we
discriminate the origins of underlying processes and provide the site's
environmental sensitivity. Our method aims to create a virtual vault at
InSight, shielding the seismometers with effective post-processing in
lieu of a physical vault. This allows us to describe the environmental
and seismic signals over a sequence of sols, to quantify the wind and
pressure injection, and estimate the seismic content of possible
Marsquakes with a signal-to-noise ratio that can be quantified in terms
of environmental independence. Finally, we exploit the temporal energy
correlations for source attribution of our observations.