Understanding the physical processes in the solar wind and corona which
actively contribute to heating, acceleration, and dissipation is a primary
objective of NASA's Parker Solar Probe (PSP) mission. Observations of coherent
electromagnetic waves at ion scales suggests that linear cyclotron resonance
and non-linear processes are dynamically relevant in the inner heliosphere. A
wavelet-based statistical study of coherent waves in the first perihelion
encounter of PSP demonstrates the presence of transverse electromagnetic waves
at ion resonant scales which are observed in 30-50\% of radial field intervals.
Average wave amplitudes of approximately 4 nT are measured, while the mean
duration of wave events is of order 20 seconds; however long duration wave
events can exist without interruption on hour-long timescales. Though ion scale
waves are preferentially observed during intervals with a radial mean magnetic
field, we show that measurement constraints, associated with single spacecraft
sampling of quasi-parallel waves superposed with anisotropic turbulence, render
the measured quasi-parallel ion-wave spectrum unobservable when the mean
magnetic field is oblique to the solar wind flow; these results imply that the
occurrence of coherent ion-scale waves is not limited to a radial field
configuration. The lack of strong radial scaling of characteristic wave
amplitudes and duration suggests that the waves are generated {\em{in-situ}}
through plasma instabilities. Additionally, observations of proton distribution
functions indicate that temperature anisotropy may drive the observed ion-scale
waves.
