Astrometric and timing effects of gravitational waves

Gravitational wave detection can be done by precision timing of millisecond pulsars, and (with less likelihood) by precision astrometry on distant objects whose light or radio waves pass through gravitational waves on their way to our observatories. Underlying both of these is the relatively simple theory of light propagation in spacetimes with gravitational waves, which is also the basis of interferometric gravitational wave detectors. I review this theory and apply it to the timing and astrometric methods of detection. While pulsar timing might even be the first way that we directly detect gravitational waves, light deflection by gravitational waves seems out of reach.