Flight test performance of a high precision navigation Doppler lidar

Pierrottet, Diego F.; Amzajerdian, Farzin; Petway, Larry B.; Barnes, Bruce W.; Lockard, George E.

doi:10.1117/12.821902

Cited by 31 publications

(16 citation statements)

References 2 publications

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“…The NDL was developed through NASA-LARC and has been validated and revised throughout numerous ALHAT field test campaigns on airplanes and helicopters. [15][16][17] These field tests have taken the NDL from demonstrations of the basic measurement concept with early prototypes, through hardware, electronics, and packaging revisions, and to implementation and performance characterization of the current-generation sensor. The current-generation NDL design is based on an all fiber-optic component architecture that is compact, robust, and simple to integrate into a host vehicle.…”

Section: Current Generation Alhat Sensorsmentioning

confidence: 99%

Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

Carson

Trawny

Robertson

et al. 2014

AIAA SPACE 2014 Conference and Exposition

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The Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project has developed a suite of prototype sensors for enabling autonomous and safe precision landing of robotic or crewed vehicles on solid solar bodies under varying terrain lighting conditions. The sensors include a Lidar-based Hazard Detection System (HDS), a multipurpose Navigation Doppler Lidar (NDL), and a long-range Laser Altimeter (LAlt). Preparation for terrestrial flight testing of ALHAT onboard the Morpheus free-flying, rocket-propelled flight test vehicle has been in progress since 2012, with flight tests over a lunar-like terrain field occurring in Spring 2014. Significant work efforts within both the ALHAT and Morpheus projects has been required in the preparation of the sensors, vehicle, and test facilities for interfacing, integrating and verifying overall system performance to ensure readiness for flight testing. The ALHAT sensors have undergone numerous stand-alone sensor tests, simulations, and calibrations, along with integrated-system tests in specialized gantries, trucks, helicopters and fixed-wing aircraft. A lunar-like terrain environment was constructed for ALHAT system testing during Morpheus flights, and vibration and thermal testing of the ALHAT sensors was performed based on Morpheus flights prior to ALHAT integration. High-fidelity simulations were implemented to gain insight into integrated ALHAT sensors and Morpheus GN&C system performance, and command and telemetry interfacing and functional testing was conducted once the ALHAT sensors and electronics were integrated onto Morpheus. This paper captures some of the details and lessons learned in the planning, preparation and integration of the individual ALHAT sensors, the vehicle, and the test environment that led up to the joint flight tests.

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Section: Current Generation Alhat Sensorsmentioning

confidence: 99%

Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

Carson

Trawny

Robertson

et al. 2014

AIAA SPACE 2014 Conference and Exposition

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“…Additionally, the Doppler Lidar provides high resolution altitude and ground-relative attitude data that may further improve precision navigation to the identified landing site. Description of the Doppler lidar and its capabilities have been reported earlier 2,3 . The Laser Altimeter provides independent altitude data over a large operational altitude range of 20 km to 100 m. All three laser sensors have a nominal update rate of 30 Hz.…”

Section: Inroductionmentioning

confidence: 99%

Utilization of 3D imaging flash lidar technology for autonomous safe landing on planetary bodies

et al. 2010

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NASA considers Flash Lidar a critical technology for enabling autonomous safe landing of future large robotic and crewed vehicles on the surface of the Moon and Mars. Flash Lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes during the final stages of descent and landing. The onboard flight comptuer can use the 3-D map of terain to guide the vehicle to a safe site.The capabilities of Flash Lidar technology were evaluated through a series of static tests using a calibrated target and through dynamic tests aboard a helicopter and a fixed wing airctarft. The aircraft flight tests were perfomed over Moonlike terrain in the California and Nevada deserts. This paper briefly describes the Flash Lidar static and aircraft flight test results. These test results are analyzed against the landing application requirements to identify the areas of technology improvement. The ongoing technology advancement activities are then explained and their goals are described.Key words: Flash Lidar, Ladar, 3-D Imaging, Laser Radar, Laser Remote Sensing, Landing Sensor INRODUCTIONThe imaging Flash Lidar is being considered as the primary sensor, due to its ability to provide 3-Dimensional images of surfaces and hazards, for future robotic and manned landing missions to the Moon and Mars. An imaging lidar system records a three dimensional (3D) image of a scene by converting intensity versus time of flight of short laser pulses into intensity versus distance along the line of sight for each spatially resolved area within a 2D image. In older, more conventional imaging lidar systems, each 2D pixel is recorded with a separate laser pulse. Thus many laser pulses are required to record large, multi-pixel images. A Flash Lidar system records full 3D images with a single laser pulse, permitting higher data rates and freezing out movement within the scene and motion of the transmitter/receiver platform. The need for high speed raster scanners to sequentially address image pixels is also eliminated. The receiver is much like the familiar digital camera, but with "smart pixels" that are capable of recording the required sequential temporal information. NASA Langley Research Center (NASA-LaRC) has been assessing the potentials of Flash Lidar technology as a landing sensor and working on its advancement under the Autonomous Landing and Hazard Avoidance (ALHAT) project for the past 3 years. The ALHAT project, led by NASA Johnson Space Center, is established by NASA to develop and demonstrate a guidance, navigation, and control system for future lunar missions capable of terrain hazard avoidance and precision landing under any lighting conditions anywhere on the Moon 1 .https://ntrs.nasa.gov/search.jsp?R=20100027344 2018-05-08T08:38:55+00:00Z

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“…For the second test in 2010, the lidar was engineered to a relatively compact package while improving its operational performance. Detailed description of the these two helicopter flight tests and their results are provided in referenced publications 9,10 . The third flight test was conducted in December 2012 using a prototype version of the Doppler lidar.…”

Section: System Development and Demonstrationmentioning

confidence: 99%

Doppler lidar sensor for precision navigation in GPS-deprived environment

et al. 2013

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Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

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Flight test performance of a high precision navigation Doppler lidar

Cited by 31 publications

References 2 publications

Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

Utilization of 3D imaging flash lidar technology for autonomous safe landing on planetary bodies

Doppler lidar sensor for precision navigation in GPS-deprived environment

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