A hollow-waveguide gas correlation radiometer for ultra-precise column measurements of formaldehyde on Mars

Emily L Wilson, Marc Neveu, Haris Riris, Elena M Georgieva, William S Heaps
2011 Measurement science and technology  
We present preliminary results in the development of a miniaturized gas correlation radiometer that implements a hollow-core optical fiber (hollow waveguide) gas correlation cell. The substantial reduction in mass and volume of the gas correlation cell makes this technology appropriate for an orbital mission Ð capable of pinpointing sources of trace gases in the Martian atmosphere. Here we demonstrate a formaldehyde (H2CO) sensor and report a detection limit equivalent to ~30 ppb in the Martian
more » ... ppb in the Martian atmosphere. The relative simplicity of the technique allows it to be expanded to measure a range of atmospheric trace gases of interest on Mars such as methane (CH 4), water vapour (H2O), deuterated water vapour (HDO), and methanol (CH3OH). Performance of a formaldehyde instrument in a Mars orbit has been simulated assuming a 3 meter long, 1000 micron inner diameter hollow-core fiber gas correlation cell, a 92.8 degree sunsynchronous orbit from 400 km with a horizontal sampling scale of 10 km x 10 km. Initial results indicate that for one second of averaging, a detection limit of 1 ppb is possible.
doi:10.1088/0957-0233/22/8/085902 fatcat:3h6wrlu5tnesrodhgvy4qnwx5m