Develop satellite

[dwfncar]

Initial PR for develop_satellite to develop, to start review comments.

[dwfncar]

Fixed

[colin-harkins]

@dwfncar I went through and resolved the outstanding issues. The merge conflict I think should be resolved as follows:

                            if obs_type == 'pt_sfc': 
                                pairdf = pairdf.set_index(grp_dict['data_proc']['ts_select_time'])

                            # Specify ts_avg_window if noted in yaml file. 
                            if 'ts_avg_window' in grp_dict['data_proc'].keys():
                                a_w = grp_dict['data_proc']['ts_avg_window']
                            else:
                                a_w = None 

I think once that is fixed this is good to go.

[rrbuchholz]

Fixed final conflict - should be good to merge.

If we remove "if obs_type == 'pt_sfc':" we could run into issues with xarray versus pandas dataframe.

[colin-harkins]

All of the recent changes look good to me.