Michael Kenneth Barker

LRO-LOLA

Surface Properties

• Developing new and improved maps of topography, hectometer-scale roughness, and permanently shadowed regions at the lunar poles to aid science and exploration.
• Leading the calibration and analysis of LOLA 1064-nm passive radiometry for studying surface light-scattering properties.
• Measuring geologic and space weathering effects on lunar surface roughness at sub-mm scales with very high phase-angle photometry obtained with LOLA at 532-nm.

Planetary Topography & Illumination

Mercury

• Creating high-resolution shape models of Mercury polar craters with photoclinometry to study origin and evolution of water ice and other volatiles.

OSIRIS-REx

Asteroids

• Studying surface light-scattering properties of asteroid Bennu as Co-I on OSIRIS-REx participating scientist proposal, "OSIRIS-REx Laser Altimeter 1064-nm Reflectance Investigation of Asteroid Bennu." 17-ORPSP17-0012. PI: G. A. Neumann.

Precision Safe Lunar Landing System Development

Remote Sensing

• Space Technology Announcement of Collaboration Opportunity (80HQTR19SOA01)
• Designed and implemented end-to-end performance simulations of hazard detection lidar under development at GSFC.

Game-Changing Development Program: LunaMaps

Remote Sensing

• Creating ultra-clean high-resolution topographic maps of priority lunar south pole landing sites and applying new statistical techniques to estimate height errors and their impact on illumination conditions.

Research Space Scientist

NASA/GSFC - NASA/GSFC

January 2018 - Present

• Created new and improved high-resolution LOLA elevation maps of south pole candidate landing sites for Artemis. Published results in Planetary & Space Science.
• Planned and analyzed observations made for the LOLA search for lunar horizon glow. Published results in JGR: Planets.
• Conducting data processing, data calibration & data analysis, and developing data protocols for passive radiometry collected by LOLA over the last 4 years composed of ~1.5 billion data points. This dataset is archived at the Planetary Data System, and is a new scientific resource for lunar surface characterization.
• Studying surface photometric properties of asteroid Bennu as co-investigator on OSIRIS-REx participating scientist proposal, "OSIRIS-REx Laser Altimeter 1064-nm Reflectance Investigation of Asteroid Bennu." 17-ORPSP17-0012. Principal Investigator: G. A. Neumann.
• Constructing high-resolution DEMs of Mercury polar craters to study origin and evolution of water ice and other volatiles (Code 698 Planetary Geodesy ISFM, Principal Investigator: E. Mazarico).
• Designed and implemented end-to-end simulations of Europa lander hazard avoidance lidar for Phase A study in collaboration with Code 500 & 61A personnel.

Senior Scientist

Sigma Space Corporation - NASA/GSFC

July 2015 - January 2018

• Directed the development of a new operation mode for LOLA that allows it to collect high-phase angle radiometry of the lunar surface. Such high-phase observations are of interest because they can place new constraints on the regolith reflectance behavior, which depends on grain & surface properties.
• Led development of another new instrument operation mode enabling LOLA to search for scattered sunlight from dust above the lunar surface (lunar horizon glow) with the goal of constraining dust transport processes on the surface of the Moon. Worked with LRO mission operations team to plan and execute spacecraft slews to make necessary measurements. Conducting data analysis and presenting status reports at scientific conferences and LRO project team meetings.
• Contributed to the development of sophisticated illumination modeling algorithms, particularly in the areas of light scattering and photometric behavior of the lunar surface. Leveraging these modeling tools to study surface-scattering of sunlight in the context of the lunar horizon glow search, which requires understanding and estimating potential light sources that could contribute to the measured signal.
• Derived corrections to the LOLA pointing model from analysis of nearly 1 million altimetric crossovers resulting in ~20% higher measurement accuracy of LOLA bounce point geolocation. Maximizing the scientific return of planetary laser altimeters like LOLA requires accurate knowledge of the instrument pointing because residual errors in the laser boresight model can increase geolocation errors.
• Assessed the LOLA instrument performance and pointing accuracy by analyzing in-orbit two-way laser ranging data between LOLA and the Goddard Geophysical and Astronomical Observatory. Reconstructed the spatial energy distribution in the LOLA laser far-field pattern. By comparing results obtained shortly after LRO launched and nearly 8 years later, this work has directly measured changes in the laser characteristics useful for understanding the long- term behavior of orbiting planetary altimeters.
• Performed data processing, data calibration, data analysis, and developing data protocols for passive radiometry collected by LOLA over the last 4 years composed of ~800 million data points. This dataset will be archived at the Planetary Data System, and will form a new scientific resource for lunar surface characterization.
• Disseminated science results through presentations at scientific conferences, such as American Geophysical Union (AGU) Fall Meeting, Lunar and Planetary Science Conference (LPSC), and team meetings (LRO Project Science Working Group, GRAIL/LOLA joint science team).
• Applied state-of-the-art least squares fitting techniques to time-of-flight altimetric data collected by the Mercury Laser Altimeter (MLA) aboard the MESSENGER spacecraft to estimate important geophysical planetary properties of the terrestrial planet, Mercury. These properties (spin rate, spin axis orientation, and libration) are sensitive to its interior structure and evolution. Developed software to generate geophysically realistic test data and solve for rotational parameters.
• Co-supervised college-level summer intern on 1-month project to derive digital elevation models of Mercury using the Ames Stereo Pipeline and images acquired with the Mercury Dual Imaging System aboard MESSENGER. The student presented her work as a poster at AGU.

Support Scientist Associate

Sigma Space Corporation - NASA/GSFC

July 2013 - July 2015

• Applied advanced optimization algorithms and least-squares fitting methods to ~1 million altimetric crossovers from LOLA to measure the lunar body tide for the first time ever from orbit, resulting in co-authored peer-reviewed professional paper in Geophysical Research Letters. This measurement provides an additional constraint on geophysical models of the lunar interior.
• Developed and calibrated a new instrument operation mode in which LOLA acts as a precise 4-pixel radiometer, extending LRO’s capabilities for multi- wavelength surface characterization. Processed first year of passive radiometry (200 million data points) and examined the phase function's dependence on geologic parameters. Published the results in peer-reviewed 2016 Icarus LRO Special Issue.
• Demonstrated a new mode of instrument operation in which LRO orbit predictions and the LOLA lunar topographic model can be used to increase LOLA’s maximum range by up to ~20%. This mode can be exploited in the future as the LOLA laser energy declines and the maximum range at which it can detect the return pulses decreases.
• Developed novel techniques for combining stereo imaging data with laser altimetry data to take advantage of their complementary strengths and weaknesses. Co-registered 43,200 stereo-derived topography models from the Japanese SELENE Terrain Camera with 4.5 billion topographic heights from the LOLA dataset yielding an improved, publicly-available, lunar topography model, called SLDEM2015. Increased the number of vertical residuals less than 5 m from 50% before co-registration to 90% after co-registration. Published the results in 2016 Icarus LRO Special Issue.
• The LOLA data processing pipeline occasionally misclassifies spurious noise returns as valid. Wrote a software program to automatically edit LOLA topographic profiles using the SLDEM2015 resulting in the recovery of ~7.5 million valid ground returns and the removal of ~75,000 invalid returns.

Data Analyst Associate

Sigma Space Corporation - NASA/GSFC

April 2011 - July 2013

• Improved the scientific value of the LOLA dataset by scheduling daily LOLA slews to fill gaps in surface coverage resulting in a 60% decrease in the number of gaps over 3.5 kilometers wide. Filling gaps in surface coverage improves the co-registration of laser altimetry and stereo imagery.
• Constructed topographic slope and roughness maps from LOLA altimetry, which were archived and distributed to the scientific community on the Planetary Data System Geosciences node website. These maps assist planetary researchers in geophysical studies of the lunar surface.
• Derived an improved range bias correction for one-way laser ranging data that resulted in smaller residuals between the predicted and actual pulse receive times. This dataset allowed the laser ranging investigation of LRO/LOLA to demonstrate that one-way time-of-flight measurements of laser pulses from Earth-based ground stations to LRO can improve the accuracy of spacecraft orbit reconstruction.

Postdoctoral Research Fellow

University of Edinburgh - Edinburgh, U.K.

January 2008 - December 2010

• Conducted a wide-field survey of the galaxy NGC 2403 using images obtained with the Subaru telescope. Applied state-of-the-art point spread function fitting software to the images providing an extensive catalog of colors and brightnesses of stars in this galaxy. Compared the spatial distribution of stars with galactic structural models to prove the existence of a faint, extended structural component. Published a paper on this work in Monthly Notices of the Royal Astronomical Society.
• Exploited the unique capabilities of the Hubble Space Telescope Advanced Camera for Surveys to study the ages and chemical compositions of two fields in the far outer disk of spiral galaxy M33. Applied sophisticated statistical tests and optimization methods to the colors and brightnesses of individual stars to derive the star formation history. Reviewed and assimilated literature to aid in data analysis and interpretation of results, which offer one of the most detailed views of the peripheral regions of any disk galaxy. Published a paper on this work in Monthly Notices of the Royal Astronomical Society. Gave an invited seminar at Liverpool John Moores University.
• Conceived of project and directed college student during 8-week Senior Honors Thesis culminating in written report and poster presentation given by the student.

American Geophysical Union

2012 - Present