Assessment of errors and biases in retrievals of X&amp;lt;sub&amp;gt;CO2&amp;lt;/sub&amp;gt;, X&amp;lt;sub&amp;gt;CH4&amp;lt;/sub&amp;gt;, X&amp;lt;sub&amp;gt;CO&amp;lt;/sub&amp;gt;, and X&amp;lt;sub&amp;gt;N2O&amp;lt;/sub&amp;gt; from a 0.5 cm&amp;lt;sup&amp;gt;−1&amp;lt;/sup&amp;gt; resolution solar viewing spectrometer