probe for the existence of Rayleigh scattering and the broad absorption wings of the NaI doublet that are expected to be present in the cloud free atmospheres of hot Jupiters [@SeagerSasselov].

Transmission spectroscopy is often focussed on inflated hot Jupiters; planets with very low density due to their large radii and relatively low masses. As a result of their low densities, low surface gravities and high temperatures these planets have large atmospheric scale heights, $H$, given by

$$\label{eq:scaleheight}
H = \frac{kT}{g\mu}$$

where $k$ is Boltzmann’s constant, $T$ is the temperature of the planet, $g$ is the acceleration due to gravity and $\mu$ is the mean molecular mass. The outermost $\sim$ 5 scale heights may account for up to 10% of the cross sectional area of a hot Jupiter, where different atmospheric species can affect the observed transmission spectrum [@Brown2001]. The relative size of the planet’s scale height to the stellar disc governs the amplitude of the transmission signal.

WASP-52b [@Hebrard2013] is an extremely inflated hot Jupiter, with a mass of 0.46M$\mathrm{_{J}}$ and radius of 1.27R$\mathrm{_{J}}$ giving it a mean density of 0.299g/cm$^3$. It orbits its 0.87M$_{\odot}$ K2V host star with a period of 1.75 days. Due to the combination of 