Diffuse clouds form an essential link between the death and birth of stars which makes them ideal laboratories for the study of interstellar chemistry. But being completely exposed to radiation fields, the low density diffuse clouds were considered to be bereft of molecular species. But over time, a wide range of molecules have been detected with the advent of space borne observatories and telescopes. Much like H2 studies conducted in the dense regions, those in the diffuse regions were carried out using CO as the preferred chemical tracer. However, indirect observations by Blitz et al. (1990) have provided ample proof of diffuse molecular clouds containing volume densities of H2 that were too low to even excite the low lying rotational states of CO, motivating the search for alternative tracers for H2 in diffuse clouds. This search resulted in the use and establishment of interstellar hydrides such as HF, CH and OH as tracers for H2. CH stands out from its hydride counterparts HF and OH as a tracer for H2 because it possesses a tight correlation with H2, [CH]/[H2] = 3.5 × 10−8 in the low (H2) density limit (Sheffer et al. 2008). The CH spin-rotational transition near 2 THz obtained using GREAT onboard SOFIA is seen in deep absorption towards actively star forming regions W49 and W51. A rigorous tool was developed, to first fit and then derive the total column densities of CH using a minimum number of a priories. This tool utilizes the Wiener Filter and further deconvolves the hyperfine structure from the observed spectrum to reveal the underlying one. The column densities of CH that were derived from the deconvolved spectra establish this transition as a tool for ultimately measuring the column densities of molecular hydrogen. A wide array of observational techniques and instruments can be used to study line of sights (LOS) composed of diffuse clouds, it is hence important to be able to relate these different observational regimes. But interpreting the ground state radio lines of CH near 3 GHz are difficult as they are mainly found in emission (even against strong continuum sources), initiating weak level inversion and maser action. To form a quantitative understanding of these lines we took advantage of the fact that it shares a common lower level with the 2 THz transitions and further employed a non-LTE radiative transfer code RADEX to model the physical and excitation conditions of its surrounding regions.