Tunable Mid-infrared Spectropscopic Imaging Lidar for 4D Volatile Mapping

Technology & Missions

Our objective of this selected ROSES PICASSO project is to develop a widely tunable mid-infrared spectroscopic lidar to perform 4D reflectance experiments regardless of illumination, with the sensitivity to map the abundances of critical lunar volatiles including H₂O, CO₂, NH₃, and H₂S at kilometer ranges from the observation site. Each measurement will include a position (X,Y) in the field of view, a time of flight (range), and a reflectance value. The goal of this work is to increase the TRL of the instrument from TRL 2 to TRL 4. Proposed specific tasks include building the spectrometric receiver, performing gated imaging at a range of 1.5 km, and performing system tests over the entire wavelength range of icy lunar simulants under cryogenic vacuum conditions.

Our tunable lidar design is based on two complementary technologies: an optical parametric oscillator (OPO) laser and a gated imaging HgCdTe APD camera. The pulsed laser can be continuously tuned between 2 and 4 microns in wavelength. The HgCdTe APD camera is single photon sensitive and operates with high quantum efficiency over the spectral range from the visible to 4.3 microns. By gating the camera, signals are integrated only when the laser pulses illuminate the scene, which greatly improves the measurement signal to noise ratio. Moving the gate time away from the laser pulses enables passive reflectance measurements using the same system.

This instrument will provide new measurements informing the extent and origin of polar volatile deposits as well their composition and meter-scale distribution. Our technology would provide valuable surface spectroscopic measurements in other planetary applications with challenging illumination conditions. These include diurnal and seasonal cycles of cometary surfaces, where solar insolation drives volatile ice deposition, sublimation, and redistribution as well as generation of the gaseous coma and tail.

Small All-range Lidar (SALi) for Small Body Exploration

Asteroids

Under the ROSES MatISSE program, this effort will mature to TRL 6 a combination science and navigation swath-mapping lidar for small body missions. Dr. Cremons leads the algorithm development portion of this program and acts as the instrument systems engineer. This instrument represents a new class of planetary lidar by combining three technologies (RZPN code modulation, fiber laser, HgCdTe APD) to create a system that is sensitive over six orders of magnitude, allowing it to operate from hundreds of kilometers in range down to the surface. This enables the instrument to provide survey science on approach (spin, body shape), provide sub-meter scale mapping of the body (topography, reflectance, slope, roughness), and act as a guidance and navigation sensor during landing or surface sampling (range, velocity).

Small Lidar for Profiling Wind and Water Vapor from Planetary Landers

Remote Sensing

Under the ROSES PICASSO program, this effort is to build and test a breadboard lidar system for Doppler wind and water vapor profile retrieval. The system is design for a lander or rover on Mars with an off-zenith, dual-transceiver design to obtain vector winds to the top of the planetary boundary layer. In addition, water vapor absorption lines near 1910 nm will be used to profile water vapor absorption as a function of altitude at all times of day and over the course of a Mars year. Field testing of the breadboard instrument will be done at Mauna Kea Observatory where dry conditions and low atmospheric pressure will be used to simulate Mars surface conditions.

MARLI: Mars Lidar for Wind and Aerosol Measurements from Mars Orbit

Mars

Dr. Cremons has worked on both the PICASSO and MatiSSE efforts to mature a direct detection Doppler lidar for global Mars wind retrievals from orbit. Under PICASSO, he co-led the build and testing of the breadboard Doppler lidar in the laboratory at GSFC and the test field campaign at the Goddard Geophysical and Astronomical Observatory to measure wind from aerosol backscattering Earth's atmosphere. He also developed the wind retrieval algorithm for the PICASSO and MatISSE programs. Under MatISSE, Dr. Cremons led the optical and mechanical design of the brassboard/prototype instrument and is currently leading the prototype testing.

Commercial Lunar Payload Services

Moons

Dr. Cremons has worked on a small team to design, build, and flight-qualify miniature lunar retroreflector arrays (LRAs) for Lunar Landers under the CLPS program. His work included leading the thermal vacuum, optical, and vibration testing of the arrays including developing an automated optical test system and thermal vacuum test setup. He also designed and fabricated vacuum-compatible optical housings to prevent optics contamination between integration and launch. To date, five LRA units have flown, with three deployed on the surface.

Lunar Flashlight

Technology & Missions

Science Co-I and lead of instrument model lead.

American Geophysical Union

2018 - Present

Materials Research Society

2015 - 2016