Sciences and Exploration Directorate

David Lloyd Rabine

((AST, EARTH SCIENCES REMOTE SENSING))

David Lloyd Rabine's Contact Card & Information.
Email: david.l.rabine@nasa.gov
Phone: 301.614.6771
Org Code: 61A
Address:
NASA/GSFC
Mail Code 610.9
Greenbelt, MD 20771
Employer:
NASA

Missions & Projects

Brief Bio


David Rabine arrived at Goddard directly from bachelor's work in Aerospace Engineering at UMCP, and was introduced to the world of experimental airborne lidar. He has grown in roles and responsibilities covering all aspects of aircraft operations including post mission data processing. His space experience is working on two shuttle based hitchhiker laser altimeters (SLA-1 and SLA-2). He returned to college to augment skills in optical instrumentation and space systems with a Masters degree in Applied Physics from Johns Hopkins University, and has continued to expand experiences with research instrumentation having helped developed several air and space borne lidars in house at GSFC: ATLAS, RASCAL, SLICER, SLA, VCL (BCE), KILT, LVIS, LVIS facility, GEDI and currently HDL / SPLICE. He has participated in many field campaigns and has experience working with many different agency personnel and instrument teams in data collection. Collaborators include ESA, University of Maryland, NOAA, NRL, DOE, NASA Armstrong, Langley and Wallops. The small team environment working at NASA Goddard has fostered a wide breadth of experience resulting in many successful airborne and space shuttle based remote sensing lidar experiments. Our teams are small enough that each member becomes well rounded in a broad range of disciplines, and the team as a whole is agile.

Current Projects


LVIS - Software Lead

Remote Sensing

NASA's Land, Vegetation, and Ice Sensor (a.k.a. the Laser Vegetation Imaging Sensor  https://lvis.gsfc.nasa.gov/ ) or "LVIS", is a scanning laser altimeter instrument that is flown, by aircraft, over target areas to collect data on surface topography and vegetation coverage.


HDL - Demo Data Systems

Remote Sensing

HDL (Hazard Detection Lidar) is a small remote sensing imaging lidar that will sample the surface of a body during descent and generate DEMs (Digital Elevation Models) in real time. The surface models will be sent to the spacecraft for descent adjustments during landing to help determine a suitable landing zone and glean the spacecraft's location by comparing the sampled surface model to existing DEM information. Currently I am working on the demonstrator hardware and software acquiring early data sets, consulting on the acquisition scheme and assisting in creating processing workflows from raw data to DEM products. The demo instrument has successfully collected full rate static and dynamic scans as of April 2021.

Positions/Employment


Physical Scientist

NASA - 8800 Greenbelt Road Code 61A Greenbelt, MD 20771

February 2009 - Present

Continuation of work begun as a contractor developing lidar systems for airborne and spaceborne remote sensing applications.


Senior Technical Staff

Science Systems and Applications, Inc. (SSAI) - 8800 Greenbelt Road Code 924.0 Greenbelt, MD 20771

September 1992 - February 2009

Lidar development and operations for the experimental instrumentation branch (924) and later the laser remote sending branch (624)

Teaching Experience


Guest Lectures at CCBC & UMCP Mechanical Engineering Remote Sensing Course (2017 - 2021)

Prepared and gave a one hour talk on lidar fundamentals to a class of mechanical engineering students at University of Maryland College Park. The discussion focused on pulsed lidar basics, LVIS instrument specifics and real world issues encountered in developing and fielding experimental instrumentation.

In 2021 I gave this same talk to a class of Community College of Baltimore County (CCBC) aviation students.

Gabon Data Processing Course (2016)

Assisted creating and working with students on data processing examples using LVIS data to a group of students as part of the AfriSAR outreach campaign.

ISRSE LVIS Data Processing Course (2005, 2009)

Created a several hour session on processing LVIS data using IDL and worked through several processing demonstration examples.

Education


M.S. in Applied Physics, Johns Hopkins Applied Physics Lab, Laurel, MD 2001

  • Concentrations: Optical design and Detectors & Space Systems Engineering

B.S. In Aerospace Engineering, University of Maryland, College Park, MD 1992

  • Concentrations: Computer Assisted Design and Analysis, Propulsion, Space Systems Engineering

Professional Service


ATLAS (1992-1994) - Installed and operated DOS based data system and wrote supporting processing code for calibration routines and data analysis.

RASCAL (1995-1996) – Developed the DOS based real time system for high repetition rate (5khz) lidar collection on first generation Pentium computers. Created a suite of processing software for reducing the data into 3D elevation models.

SLICER (1997- 1998) – Created many variations on the original ATLAS software written by Bryan Blair to fill needs of various experiments we conducted while developing early galvanometer scanning lidar.

SLA (1994-1997) – Wrote the communications and ground station control software which communicated with the flight code via RS-422 data packets. Developed the real time display and control for system operations and monitoring. Operated the instrument while on orbit remotely from the payload operations center at GSFC.

VCL / BCE (1998-2000) – Bench checkout system development for the VCL lidar instrument (MBLA). Created a custom C based reverse altimeter which generated light signals through an AWG and diode to simulate Earth returns to the VCL instrument. Integrated the BCE module as a DLL for the ASIST test control software.

KILT (2005 – 2008) – Created the embedded real time data system for this automated atmospheric lidar trailer. This real time system is monitored by a standard linux process which oversees day to day operations of the lidar on its own, and periodically it contacts a home station over a low bandwidth iridium internet connection. This system uplinks data snapshots and telemetry while storing the main data internally. I wrote the real time system, the oversight program and a network based client for real time interaction using a standard linux distribution framework to minimize development efforts for the bulk of the required tasks. The system leveraged the linux operating system as much as possible to save on development time.

LVIS (1998 – Present) – Developed both real time data systems (the first in DOS, the second in Real Time Linux, the third in RTAI real time linux) for scanning lidar collection and technique improvement for high altitude, waveform based lidar imaging. LVIS is our current test bed allowing us to experiment with techniques to improve our lidar data coverage and collection and is the culmination of our experiences with earlier systems. The real time data system was upgraded to RTAI based Ubuntu 9 real time kernel in 2010 and expanded to 3 digitizer channels.

LVIS-GH (2010 – 2014) – Lead the developed the Global Hawk version of the LVIS flight software along with the ground based GUI and Commanding software. Used the Xenomai real time modifications to the standard Ubuntu Linux kernel to develop a real time embedded flight system for operations on the NASA Global Hawk platform. Instrument command and control is accomplished with internet packets. First flight occurred June 2013.

LVIS Facility (2014-Present) – Lead software design for the real time data acquisition system for the LVIS facility instrument. Based on an “off the shelf” RT_PREEMPT v2.6 Linux kernel provided by the CERN project, we created a real time system relying on embedded digitizer FGPA code to collect the outgoing and returning lidar waveform data at 5 kHz and above. The FPGA executes a pulse finding algorithm in real time, and packages up just the resulting waveform data to ship to the data system for storage. All channels are completely independent but also tied together by a common clock as there are two channels per digitizer card. Waveform data is 12 bit and the same ADC chip that GEDI employs. First flight was April 28, 2017. System was refactored to replace real time linux with a network controlled microcontroller the summer of 2018. Version 2.0, a clean sheet re-write of the core data system flew in November 2018 and is the current stable LVIS system.

GEDI (2017-2019) - Consulted with the creators of the Bench Checkout Equipment (BCE) for the Global Ecosystem Dynamics Investigation (GEDI) on creating testing scenes and waveform test scripts to characterize to lidar. Provided data sets for the FPGA group from our LVIS sensor to use as test waveforms for the onboard digitizer logic that would end up flying in GEDI on the International Space Station (ISS). Worked closely with the BCE team to ensure thorough instrument testing in a realistic simulated environment. GEDI successfully launched on December 5, 2018 aboard a Spacex Falcon 9 and successfully operated aboard the ISS until Spring of 2023 when it was put into cold storage.

HDL / SPLICE (2019-Present) – Data systems lead for the drone / demo version of the HDL (Hazard Detection Lidar). Creating a laboratory and demo version of the soon to be realized space flight system for acquiring early data sets for algorithm development and acquisition scheme refinement. Using commercial hardware, we've created a system that records 8 million raw fully recorded waveform samples in two seconds with centimeter level range precision.

 

Awards


  • ETD Science & Technology Advancement Award, "HDL Tech Demo Team", 2021.
  • HBG 2021 Peer Award Scientific/Technical Support: Outstanding Organizational and Engineering Support for the Demonstration and TRL Advancement of Goddard's Hazard Detection Lidar
  • NASA RHG Exceptional Achievement Customer Service Team awards NASA’s GSFC WFF C130 ARISE Mission Team “For exceeding customer expectations through excellence in engineering, modification, maintenance, and excecution of the 2014 C130 Aircraft ARISE science mission”.
  • NASA Group Achievement Award to Icebridge award “For exceptional achievement in supporting of NASA's IceBridge Campaign”, 2011.
  • NASA Time Off Award “For your extreme dedication & hard work supporting the LVIS airborne flight campaigns.”
  • Science Systems and Applications Performance Award for “Generation of high-quality waveform-based imaging lidar data for estimating vegetation, biomass, bird habitat, coastal hazards and topographic change”, May 2007.
  • Science Systems and Applications Performance Award for “LVIS aircraft missions in Costa Rica, March 2005 and Florida, May 2005”, September 2005
  • Science Systems and Applications Performance and Excellence Award, “In recognition of his wide range of state of the art system development contributions and dedicated support for the LTP program of airborne altimeter field investigations”, September 1998.
  • NASA / Goddard Space Flight Center Small Payloads Project Participation and Appreciation Award, “In recognition and appreciation of your contribution to the success of the first Technology Applications and Science (TAS-01) mission”, September 1998.
  • NASA / Goddard Space Flight Center Participation and Appreciation Award, “In appreciation for your effort, dedication, and hard work, which contributed to the success of the Shuttle Laser Altimeter-01 Mission”, September 1996.
  • NASA / Goddard Space Flight Center Special Act Group Award for the Shuttle Laser Altimeter Instrument Development Team, “In recognition of your successful development and on-time, within-budget delivery of the Shuttle Laser Altimeter Instrument for flight as a Hitchhiker payload on the Space Shuttle, September, 1995.
  • NASA / Goddard Space Flight Center and UMBC Research Fellows Program Certificate, “A pioneer in the effort to unite the university and government laboratory communities through a program of scientific and engineering research, interaction and communication between NASA / Goddard Space Flight Center and the University County”, August 1995.

Other Professional Information


NASA Technical Management Training - 2015

NASA Project Scientist Training - 2014

NASA ROSES Proposal Writing - 2014

APPEL Training

  • Requirements Development and Management - 2013
  • Fundamentals of System Engineering - 2012
  • Project Scheduling Basic and Advanced Concepts - 2012
  • Team Leadership - 2012

 

Special Experience


Previously certified Linux system administrator (3 Brainbench certifications in administration and security: expired 2009)

Extensive C language computer programming

Custom Linux device driver and low level programming for high speed real time data collection and interfacing between software & hardware.

Real time data acquisition system development

Automated and embedded system creation and deployment

Remote access system development (network connected systems)

IDL Language Computer Programming for processing and analysis

GMT scripting language for publication graphic generation

FORTRAN, MYSQL, PERL, PHP, Java and Shell Script Programming

Extensive field study in lidar system alignment, calibration and operational experiment experience for precise measurement

Geodetic GPS field survey data collection and processing experience

LVIS instrument management and laser safety officer for aircraft operations

 

Completed my private pilot license (March 2019 - November 2021) despite my large travel and pandemic breaks.

  • my first solo was in N6529L, a 1980 Cessna 152 on January 22nd, 2020 after a large gap in training due to work travel and life interruptions.
  • passed the ground school private pilot written exam in April 2021 after a virtual ground school during the Covid-19 pandemic so ready to do some more flying!
  • Passed my PPL Practical Flight Test: Certificate: PRIVATE PILOT  Date of Issue: 11/3/2021 YAY!

Publications


Refereed

2017. "Canopy height and structure measurements of Gabon from medium-footprint waveform lidar." 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS) 4294-4295 [10.1109/igarss.2017.8127952] [Proceedings]

2017. "Arctic Radiation-IceBridge Sea and Ice Experiment (ARISE): The Arctic Radiant Energy System During the Critical Seasonal Ice Transition." Bulletin of the American Meteorological Society 98 (7): 1399-1426 [10.1175/bams-d-14-00277.1] [Journal Article/Letter]

2008. "Assessing the Performance of 20-25m Footprint Waveform Lidar data Collected in ICESat Data Corridors in Greenland." Geophysical Research Letters 35 (24): [10.1029/2008GL035774] [Journal Article/Letter]

2006. "Validation of SRTM Elevations Over Vegetated and Non-vegetated Terrain Using Medium Footprint Lidar." Photogrammetric Engineering & Remote Sensing 72 (3): 279-285 [10.14358/pers.72.3.279] [Journal Article/Letter]

2000. "An airborne scanning laser altimetry survey of Long Valley, California." International Journal of Remote Sensing 21 (12): 2413-2437 [10.1080/01431160050030547] [Journal Article/Letter]

2000. "Using airborne laser altimetry to detect topographic change at Long Valley Caldera, California." Remote Sensing of Active Volcanism (Geophysical Monograph Series) 116 249-264 [10.1029/gm116p0249] [Article in Book]

1999. "The Laser Vegetation Imaging Sensor: a medium-altitude, digitisation-only, airborne laser altimeter for mapping vegetation and topography." ISPRS Journal of Photogrammetry and Remote Sensing 54 (2-3): 115-122 [10.1016/s0924-2716(99)00002-7] [Journal Article/Letter]

1996. "Georeferencing of airborne laser altimeter measurements." International Journal of Remote Sensing 17 (11): 2185-2200 [10.1080/01431169608948765] [Journal Article/Letter]

Non-Refereed

2013. "Fiber Scanning Array for 3 Dimensional Topographic Imaging." Imaging and Applied Optics. OSA Technical Digest (online) [Full Text] [10.1364/aopt.2013.jtu4a.24] [Proceedings]

2000. "Technical Report Series on the BorealEcosystem-Atmosphere Study (BOREAS): Volume 93, SLICER Airborne Laser Altimeter Characterization of Canopy Structure and Sub-canopy Topography for the BOREAS Northern and Southern Study Regions: Instrument and Data Product Description." NASA/TM-2000-209891 93 51 [Full Text] [Report]

1996. "Shuttle Laser Altimeter (SLA): A pathfinder for space-based laser altimetry and lidar." 1995 Shuttle Small Payloads Symposium NASA-CP-3310 83-90 [Full Text] [Proceedings]

1996. "Development and test of a raster scanning laser altimeter for high resolution airborne measurements of topography." 1996 International Geoscience and Remote Sensing Symposium (IGARSS 96) - Remote Sensing for a Sustainable Future 423-426 [10.1109/igarss.1996.516361] [Proceedings]