Dr. Michael D. Smith Profile

Dr. Michael D. Smith

at NASA Goddard Space Flight Ctr

SPIE Involvement:

Author

Publications (2)

SPIE Journal Paper | 21 April 2021

Observations of Mars with ALMA: potential for future constraints of global circulation models

Maxwell C. Parks, Conor Nixon, Geronimo Villanueva, Michael Smith, Alain S. Khayat, Alexander Thelen, Eric Villard, Steven Charnley, Patrick G. Irwin

JATIS, Vol. 7, Issue 02, 025001, (April 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.2.025001

KEYWORDS: Mars, Atmospheric modeling, Data modeling, Spatial resolution, Observatories, Calibration, Interferometers, 3D modeling, Interferometry, Climatology

Read Abstract +

Proceedings Article | 9 October 2018 Presentation + Paper

Development of a Mars lidar (MARLI) for measuring wind and aerosol profiles from orbit

Daniel Cremons, James Abshire, Graham Allan, Xiaoli Sun, Haris Riris, Michael Smith, Scott Guzewich, Anthony Yu, Floyd Hovis

Proceedings Volume 10791, 1079106 (2018) https://doi.org/10.1117/12.2325408

KEYWORDS: Wind measurement, Doppler effect, Mars, Aerosols, Telescopes, LIDAR, Atmospheric particles, Clouds, Fabry–Perot interferometers, Backscatter

Read Abstract +

Our understanding of the Mars atmosphere and the coupled atmospheric processes that drive its seasonal cycles is limited by a lack of observation data, particularly measurements that capture diurnal and seasonal variations on a global scale. As outlined in the 2011 Planetary Science Decadal Survey and the recent Mars Exploration Program Analysis Group (MEPAG) Goals Document, near-polar-orbital measurements of height-resolved aerosol backscatter and wind profiles are a high-priority for the scientific community and would be valuable science products as part of a next-generation orbital science package. To address these needs, we have designed and tested a breadboard version of a direct detection atmospheric wind lidar for Mars orbit. It uses a single-frequency, seeded Nd:YAG laser ring oscillator operating at 1064 nm (4 kHz repetition rate), with a 30-ns pulse duration amplified to 4 mJ pulse energy. The receiver uses a Fabry-Perot etalon as part of a dual-edge optical discrimination technique to isolate the Doppler-induced frequency shift of the backscattered photons. To detect weak aerosol backscatter profiles, the instrument uses a 4x4 photon-counting HgCdTe APD detector with a 7 MHz bandwidth and < 0.4 fW/Hz^1/2noise equivalent power. With the MARLI lidar breadboard instrument, we were able to measure Doppler shifts continuously between 1 and 30 m/s by using a rotating chopper wheel to impart a Doppler shift to incident laser pulses. We then coupled the transmitter and receiver systems to a laser ranging telescope at the Goddard Geophysical and Astronomical Observatory (GGAO) to measure backscatter and Doppler wind profiles in the atmosphere from the ground. We measured a 5.3 ± 0.8 m/s wind speed from clouds in the planetary boundary layer at a range of 4 to 6 km. This measurement was confirmed with a range-over-time measurement to the same clouds as well as compared to EMC meteorological models. Here we describe the lidar approach and the breadboard instrument, and report some early results from ongoing field experiments.

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years