Reference Forward Model (RFM), a line-by-line radiative transfer code, to calculate the disk integrated dayside emission spectra, modified to handle H$_2$-H$_2$ and H$_2$-He collisionally induced opacities. The collisionally induced opacity tables are taken from Barysow et al. (2001;2002) and J[ø]{}rgensen et al. (2000). The molecular line strengths for H$_2$O, CO$_2$, and CO, are from the HITEMP (Rothman et al. 2010) database and CH$_4$ is from the HITRAN 2008 database (Rothman et al. 2009). In order to keep the molecular line-lists from becoming too unwieldy we make an intensity cutoff at 298 K of 10$^{-40}$ cm molecule$^{-1}$, as recommended by Sharp & Burrows (2007).

Test on Synthetic Data
======================

First, we test the retrieval method on a synthetic data set for which we know the answer. Using this synthetic spectrum, we explore the effect that signal-to-noise and spectral resolution have on the degrees of freedom and information content.

A hypothetical hot-jupiter atmosphere is generated using $\kappa_{v_{1}}=\kappa_{v_{2}}=4\times10^{-3}$ cm$^2$g$^{-1}$, $\kappa_{IR}=1\times10^{-2}$ cm$^2$g$^{-1}$, $\alpha=0.5$, and fixed vertical mixing ratios of $f_{H2O}=5\times10^{-4}$, $f_{CH4}=1\times10^{-6}$, $f_{CO}=3\times10^{-4}$, and $f_{CO_2}=1\times10^{-7}$. The planet orbits around a G0V host star (e.g. HD 209458a) with $T_{*}=6000$ K, $R_{*}=1.14$ R$_\odot$ at a separation of $a = 0.064$ AU. The planetary properties are a radius 