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Book

LiDAR Technologies and Systems

2019-07-10
Why are vision systems fundamental and critical to autonomous flight? What are the vision system tasks required for autonomous flight? How can those tasks be approached? It addresses the role of vision systems for autonomous operations and discusses the critical tasks required of a vision system, including taxi, takeoff, en-route navigation, detect and avoid, and landing, as well as formation flight or approach and docking at a terminal or with other vehicles. These tasks are analyzed to develop field of view, resolution, latency, and other sensing requirements and to understand when one sensor can be used for multiple applications. Airspace classifications, landing visibility categories, decision height criteria, and typical runway dimensions are introduced. The book provides an overview of sensors and phenomenology from visible through infrared, extending into the radar bands and including both passive and active systems.
Technical Paper

Infrastructure-Based LiDAR Monitoring for Assessing Automated Driving Safety

2022-03-29
2022-01-0081
Building on earlier work from the IAM in creating an infrastructure- based sensor system to evaluate OSA metrics in real- world scenarios, this paper presents an approach for real-time localization and velocity estimation for AVs using a network of LiDAR sensors. The LiDAR data are captured by a network of three Luminar LiDAR sensors at an intersection in Anthem, AZ, while camera data are collected from the same intersection. ...The accuracy of both the localization and velocity estimation using LiDAR is assessed by comparing the LiDAR estimated state vectors against the differential GPS position and velocity measurements from a test vehicle passing through the intersection, as well as against a camera-based algorithm applied on drone video footage It is shown that the proposed method, taking advantage of simultaneous data capture from multiple LiDAR sensors, offers great potential for fast, accurate operational safety assessment of AV’s with an average localization error of only 10 cm observed between LiDAR and real-time differential GPS position data, when tracking a vehicle over 170 meters of roadway. ...Additional sensor modalities such as Light Detecting and Ranging (LiDAR) sensors allow for a wider range of scenarios to be accommodated and may also provide improved measurements of the Operational Safety Assessment (OSA) metrics previously introduced by the Institute of Automated Mobility (IAM).
Technical Paper

Comparison of Infrastructure- and Onboard Vehicle-Based Sensor Systems in Measuring Operational Safety Assessment (OSA) Metrics

2023-04-11
2023-01-0858
Extending upon earlier works of the Institute of Automated Mobility (IAM) that have explored the Operational Safety Assessment (OSA) metrics and infrastructure-based safety monitoring systems, in this work, we compare the performance of an infrastructure-based Light Detection And Ranging (LIDAR) system to an onboard vehicle-based LIDAR system in testing at the Maricopa County Department of Transportation SMARTDrive testbed in Anthem, Arizona. ...The sensor modalities are located in infrastructure and onboard the test vehicles, including LIDAR, cameras, a real-time differential GPS, and a drone with a camera. Bespoke localization and tracking algorithms are created for the LIDAR and cameras. ...Bespoke localization and tracking algorithms are created for the LIDAR and cameras. In total, there are 26 different scenarios of the test vehicles navigating the testbed intersection; for this work, we are only considering car following scenarios.
Technical Paper

Feasibility of Modeling Wake Vortices in Ground Effect in a Water Tunnel

2005-10-03
2005-01-3360
The minimum height to which the filaments sink is shown to compare favorably with that predicted by numerical methods and the operational data obtained from lidar. The vortex span is shown to increase at the same rate as that estimated from an empirical model based on lidar data as well. ...The vortex span is shown to increase at the same rate as that estimated from an empirical model based on lidar data as well. Vortex rebound is observed with maximum heights comparing well with other predictions.
Book

Remote Sensing from Air and Space

2007-01-01
Olsen of the Naval Postgraduate School offers an eclectic description of the technologies and underlying physics for a wide range of remote sensing systems, including optical, thermal, radar, and lidar systems. This monograph describes this diverse set of applications using full-color graphics and a friendly, readable format.
Technical Paper

Empirical Wake Turbulence Model of Tiltrotor Aircraft

2005-10-03
2005-01-3182
This paper describes the methods used to collect and reduce wake turbulence data behind two distinct types of tiltrotor aircraft using a Light Detection and Ranging (LIDAR) measurement system, which uses laser velocimetry to measure the velocity of dust particles in air that has been disturbed by the passage of an aircraft. ...The MIT LL LIDAR system measured the wake vortices with minimal pre-test preparation; we obtained a large quantity of high quality data in only a few days of testing.
Technical Paper

SLD and Ice Crystal Discrimination with the Optical Ice Detector

2019-06-10
2019-01-1934
The OID is a short-range, polarimetric lidar that samples the airstream up to ten meters beyond the skin of the aircraft. The intensity and extinction of the backscatter light correlate with bulk properties of the cloud, such as water content and phase. ...Drizzle-sized droplets, mixed with a small droplet cloud in the Collins Cloud Chamber, appear as scintillations in the lidar signal when it is processed pulse-by-pulse. Averaging the signal over multiple pulses, causes large droplets to become obscured by the small droplet background.
Magazine

Aerospace & Defense Technology: October 2020

2020-10-01
Collection, Processing, and Accuracy of Mobile Terrestrial LiDAR Survey Data in the Coastal Environment Using terrestrial LiDAR scanners coupled with a global position system/inertial navigation system to collect elevation data along the coast can help assess the accuracy of the data.
Technical Paper

Optical Ice Detector Lite: Initial Flight Test Results

2023-06-15
2023-01-1427
Drizzle-sized droplets, mixed within a small droplet cloud, appear as scintillation spikes in the lidar signal when it is processed pulse-by-pulse. Scintillation in the backscatter (in combination with the outside air temperature monitored by another probe) signals the presence of supercooled large droplets (SLD) within the cloud—a capability incorporated into the OID Lite to meet the requirements of Appendix O.
Magazine

Aerospace & Defense Technology: June 2023

2023-06-01
Airborne Inspection Sensor Evolves with LiDAR, Mid-IR and Artificial Intelligence Air Force eVTOL Research and Development Programs Make Remote Pilot Progress Creating a Digital Gateway for RF Domain Will Advance Designs That Meet DoD Initiatives Understanding the Unique RF Interconnect Requirements for Ultra-Demanding Hypersonic Missile and Satellite Applications ADS-B Classification Using Multivariate Long Short-Term Memory This analysis extends previous research that used long short-term memory-fully convolutional networks to identify aircraft engine types from publicly available automatic dependent surveillance-broadcast (ADS-B) data.
Technical Paper

Multi-Sensor Data Fusion Techniques for RPAS Detect, Track and Avoid

2015-09-15
2015-01-2475
In order to perform an effective detection of objects, a number of high performance, reliable and accurate avionics sensors and systems are adopted including non-cooperative sensors (visual and thermal cameras, Laser radar (LIDAR) and acoustic sensors) and cooperative systems (Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Collision Avoidance System (TCAS)).
Article

Phase three of DARPA’s ALIAS aircraft automation system continues

2018-10-30
The autonomous software and hardware, which was installed on an optionally piloted helicopter, executed various scenarios including automated takeoff and landing, LIDAR- and camera-based obstacle avoidance, LIDAR-based automatic landing zone selection, and low-level contour flying.
Magazine

Automotive Engineering: April 2024

2024-04-04
eFuels: An Alternative to the Alternative Synthetic fuels promise low-carbon alternatives, but can they deliver? WCX 2024: Come for the AI, stay for the optimism AI top of mind at SAE's annual technical mobility conference. A Peek at Electrify America's Charging Station Future Twenty DC fast chargers and amenities are available, but the most important detail is that everything works. Full speed ahead for second-generation Indy autonomous racers Major hardware and software upgrades underpin the Indy Autonomous Challenge racecar for 2024, proving self-driving vehicle capabilities at triple-digit speeds.
Magazine

Aerospace & Defense Technology: April 2016

2016-04-01
Electronic Warfare Next Generation FPGAs for Electronic Warfare Systems Materials: Composites Managing the Impact of Nanomaterials in Aerospace Manufacturing Aerospace Materials/Manufacturing Turbine Flow Meters Alternative Power Sources Designing a Power Generation System for a More-Electric Aircraft
Magazine

Aerospace Engineering 2000-11-01

2000-11-01
Quality in the integrated product team In the early phases of product development, quality must be engineered and managed into the product. Advancing icing detection Engineers are working to develop a capability to detect icing conditions ahead of aircraft using onboard and ground-based remote sensing systems. Testing times Methods for testing aircraft engines have changed dramatically over the years for Rolls-Royce- almost as much as the engines themselves. This is the last installment of a three-part series on aircraft engine testing.
Magazine

Mobility Engineering: September 2015

2015-09-01
The advent of stop-start technology As environmental concerns grow for R&D teams, OEMs look to bring the strategy further into the mainstream. Recycling opportunities for hybrid/electric vehicle lithium-ion batteries With limited reserves and strict environmental regulations, re-cyclers look to established extraction means to reuse, recycle, and dispose of the used batteries. Cameras look to go the distance Automakers seek vision systems with greater distances, improved reliability, and more functionality, thanks to ruggedized complementary metal-oxide semiconductor technologies. Getting right with composites With composites now a mainstay in most new aircraft de-signs, the engineering emphasis has switched from understanding if they work to thinking through the most efficient way to manufacture them, such as using design-for-manufacturing software.
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