and their impact on the [IGM]{} [see e.g. @Barkana:2007p2929; @Loeb:2013p2936; @Zaroubi:2013p2976]. Currently the astrophysics of the [EoR]{} are poorly understood. However, a wave of upcoming observations should produce a rapid advance in our understanding. At the forefront of these will be the detection of the redshifted 21 cm spin-flip transition of neutral hydrogen [see e.g. @Furlanetto:2006p209; @Morales:2010p1274; @Pritchard:2012p2958] from several dedicated radio interferometers.

The first-generation 21 cm experiments such as the Low Frequency Array (LOFAR; @vanHaarlem:2013p200 [@Yatawatta:2013p2980])[^2], the Murchison Wide Field Array (MWA; @Tingay:2013p2997)[^3] and the Precision Array for Probing the Epoch of Reionization (PAPER; @Parsons:2010p3000)[^4] are just now coming online. These have enabled progress in understanding and characterizing the relevant systematics and foregrounds, and may even yield a detection of the 21 cm power spectrum (PS) during the advanced stages of reionization [e.g. @Chapman:2012p344; @Mesinger:2014p244].

In the near future, second-generation experiments, the Square Kilometre Array (SKA; @Mellema:2013p2975)[^5] and the Hydrogen Epoch of Reionization Array (HERA; @Beardsley:2014p1529)[^6] will feature significant increases in collecting area and overall sensitivity. In addition to statistical measurements of the 21 cm PS, these second-generation experiments should provide the first tomographic maps of the 21 cm signal from the [EoR]{} [@Mellema:2013p2975], deepening our understanding of reionization-era 