GreenHouse gas Observations of the Stratosphere and Troposphere (GHOST): an airborne shortwave-infrared spectrometer for remote sensing of greenhouse gases

The authors would like to thank the team at the NASA Armstrong Flight Research Centre for their assistance during the CAST-ATTREX campaign, particularly Dave Fratello, who provided us with invaluable logistical support both before and during the NASA Armstrong deployment. Additional work (beyond that of the co-authors) on the design, mechanical build, software development, and deployment of GHOST was provided by STFCATC engineers George Davidson, Xiaofeng Gao, Brian Woodward, Brian Wilson, and Tom Baillie. We also acknowledge contributions towards the optical design of GHOST by STFC-ATC optical engineers Andy Born and Martin Black. The design, manufacture, and deployment of GHOST was co-funded by NERC and STFC through the Co-ordinated Airborne Studies of the Tropics (CAST) project, with grant numbers NE/I030054/1 (lead award), NE/J006211/1, NE/J006238/1, and NE/J006203/1. Subsequent funding from the UK Centre for Earth Observation Instrumentation (CEOI) has supported and enabled further study of GHOST beyond the original CAST project. This research used the SPECTRE and ALICE High Performance Computing Facilities at the University of Leicester. The calibration measurements described in Sect. 3 were made using facilities and laboratory space at the UK Astronomy Technology Centre (UK-ATC) in Edinburgh, UK, with further equipment and expertise provided by Chris MacLellan of the Natural Environment Research Council Field Spectroscopy Facility (NERC FSF). The retrieval code described in Sect. 5.1, originally developed for satellite measurements from above the atmosphere, was adapted for observations from an aircraft instrument within the atmosphere by Peter Somkuti at the University of Leicester. The MODIS L2 Cloud Product data used in Fig. 18 were acquired from the NASA MODIS Adaptive Processing System, located in the Goddard Space Flight Center in Greenbelt, Maryland (http://modis-atmos.gsfc.nasa.gov/MOD06_L2/, last access: 30 August 2018).