Browse Topic: Remote sensing

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Automated Vehicle Safety Consortium
IAQG-03282025-1 IAQG-03282025-1 (Current)04/02/2025
IAQG-03282025-1
IAQG-1 Standards Committee
Automatic Detection of Dead-End Roads in High-Resolution Satellite Image2025-01-716502/21/2025
There are dead-end roads in the road network, and many of them have the function of indicating specific target clues, which is of great significance in the fields of military, urban construction, and disaster relief and rescue. However, many of the important cut-offs are in mountainous or wilderness areas, and surveying them is difficult and costly. The research objective of this project is to extract the breakpoints in the road network using high-resolution Google satellite imagery, so as to provide clues and indications for the subsequent relevant work. Firstly, the image is corrected and pre-processed to highlight road edge information.Then the phase grouping method is improved by setting a double-angle threshold, filtering the edge operator to reduce the calculation error of the gradient angle, and the road network is extracted by the improved phase grouping method. And finally screens out the dead-end road points with the eight-neighbourhood method, and marks them on the
Liu, Ruohan, Haoping, Qi, Jingjie, Kang, Yanyan, Wu, Feifei, Li
An Autonomous Ground Based Multi Sensor Data Fused TDR Prediction and Monitoring System2022-26-122705/26/2022
According to a study conducted by IATA, EASA and ICAO, runway excursions are common type of incidents that leads to major accidents. Runway excursion predominantly occur due to incorrect utilization of the touchdown zone (TDZ). A ground-based multi-sensor data fused touchdown region (TDR) prediction and monitoring system is proposed in this paper. This system autonomously analyses real-time environmental data with remote sensing capability around the runway site, gathers real-time information on flight critical parameters of approaching aircraft through an ADS-B Out data link, predicts ideal TDR over the runway TDZ for a particular aircraft, and estimates the expected contemporaneous TDR based on the monitored current approach profile. If the ideal and expected TDR do not overlap, there is a chance for an excursion. In such cases, the flight parameter that needs corrective action is determined and notified to the pilot. In order to analyze dynamic environmental data, mathematical
Nagonda, Ajay Nagarajan, Manjunath, Karthik
Nanothermometers Improve Temperature ImagingTBMG-3854502/01/2021
NIST researchers are in the early stages of a massive undertaking to design and build a fleet of tiny ultra-sensitive thermometers. If they succeed, their system will be the first to make real-time measurements of temperature on the microscopic scale in an opaque 3D volume — which could include medical implants. The project is called Thermal Magnetic Imaging and Control (Thermal MagIC), and the researchers say it could revolutionize temperature measurements in many fields, including biology and medicine. Thermal MagIC will work by using nanometer-sized objects whose magnetic signals change with temperature. The objects would be incorporated into the liquids or solids being studied — the melted plastic that might be used as part of an artificial joint replacement, for example. A remote sensing system would then pick up these magnetic signals, meaning the system being studied would be free from wires or other bulky external objects.
Lenslet-Based Integral Field SpectrographTBMG-3799111/01/2020
An integral field spectrograph (IFS) is an instrument combining spectrographic and imaging capabilities. IFSs provide spectral information over a 2D field of view. In lenslet-based IFS designs, a lenslet array is placed in the spectrograph entrance plane. All beams generated by the lenslet array are fed through a dispersive element and imaged by a camera, resulting in a spectrum for each individual lenslet.
Products of Tomorrow: October 2020TBMG-3780010/01/2020
This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that innovation.
Millimeter Wave Technology Joins the Fight to Prevent Future Viral OutbreaksTBMG-3785210/01/2020
The next breakthrough in the fight against deadly viral outbreaks may be just a higher frequency away. While millimeter wave (MMW) devices are more commonly associated with military applications, remote sensing, security screening and next generation telecommunications, there is an even more pressing need for this technology. That would include breaking down barriers in research in order to gain new insight into the mechanics of viral transfer.
Development Software Handles High-Integrity Space ApplicationsTBMG-3721107/01/2020
AdaCore New York, NY
Soft Hardware for More Flexible RobotsTBMG-3700106/01/2020
Robots can be made from soft materials but the flexibility of such robots is limited by the inclusion of rigid sensors necessary for their control. Researchers have created embedded sensors that replace rigid sensors and offer the same functionality but with greater flexibility. Soft robots can be more adaptable and resilient than more traditional rigid designs. The team used machine learning techniques to create their design.
Joint Calibration of Dual LiDARs and Camera Using a Circular Chessboard2020-01-009804/14/2020
Environmental perception is a crucial subsystem in autonomous vehicles. In order to build safe and efficient traffic transportation, several researches have been proposed to build accurate, robust and real-time perception systems. Camera and LiDAR are widely equipped on autonomous self-driving cars and developed with many algorithms in recent years. The fusion system of camera and LiDAR provides state-of the-art methods for environmental perception due to the defects of single vehicular sensor. Extrinsic parameter calibration is able to align the coordinate systems of sensors and has been drawing enormous attention. However, differ from spatial alignment of two sensors’ data, joint calibration of multi-sensors (more than two sensors) should balance the degree of alignment between each two sensors. In this paper, we assemble a test platform which is made up of dual LiDARs and one monocular camera and use the same sensing hardware architecture as intelligent sweeper designed by our
Deng, Zhenwen, Xiong, Lu, Yin, Dong, Shan, Fengwu
Detailed Spectrometry Makes Dangerous-Materials Testing SaferTBMG-3639904/01/2020
Spinoff is NASA’s annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
Magneto-Optic Biosensor Using Bio-Functionalized Magnetic NanoparticlesTBMG-3582701/01/2020
Magnetic nanoparticles are leading to the development of more sensitive, rapid, and cost-effective biological sensors. These sensors can be used for a variety of applications including the detection of medical conditions and bioterrorist threats.
Aerospace & Defense Technology: October 201919AERP1010/01/2019
Artificial Intelligence and Autonomous Vehicles A "STEP" Forward for Product Lifecycle Management The Challenge of Replacing Hard Chrome Defining an Open System Architecture Standard for Defense Systems Solid-State Microwave Power Module Defeating Commercial Drone Threats with Open-Source SDR Influence of Leading-Edge Oscillatory Blowing on Time-Accurate Dynamic Store Separation Developing an understanding of, and potentially controlling, pitch bifurcation of a store release from an aircraft during flight could improve weapons delivery. Green's Function Extraction from Atmospheric Acoustic Propagation Understanding what affects acoustic waves propagating in the atmosphere is important for a variety of military applications including the development of new remote sensing techniques. Waveform Synthesis for Shock Response Spectrum Replication, Applied to Ground Vehicle Component Testing Improved test methods will help alleviate the impact of shock levels on military and commercial ground
Green’s Function Extraction from Atmospheric Acoustic PropagationTBMG-3536310/01/2019
Acoustic waves propagating in the atmosphere may undergo many effects including refraction by temperature and wind velocity gradients, scattering by atmospheric turbulence, absorption by the atmosphere (fluid), diffraction by terrain features, and absorption and reflection by a porous ground. As a result, there may be insonification in acoustic shadow zones, amplitude and phase fluctuations of the propagating sound signals, loss of signal coherence, changes in the interference maxima and minima of the direct ground reflected waves, and multipath effects. Understanding these effects is important for a variety of military applications, such as acoustic source localization and classification, noise propagation in the atmosphere, and the development of new remote sensing techniques of the atmosphere.
Green's Function Extraction from Atmospheric Acoustic Propagation19AERP10_0810/01/2019
Understanding what affects acoustic waves propagating in the atmosphere is important for a variety of military applications including the development of new remote sensing techniques. Army Research Laboratory, Adelphi, Maryland Acoustic waves propagating in the atmosphere may undergo many effects including refraction by temperature and wind velocity gradients, scattering by atmospheric turbulence, absorption by the atmosphere (fluid), diffraction by terrain features, and absorption and reflection by a porous ground. As a result, there may be insonification in acoustic shadow zones, amplitude and phase fluctuations of the propagating sound signals, loss of signal coherence, changes in the interference maxima and minima of the direct ground reflected waves, and multipath effects. Understanding these effects is important for a variety of military applications, such as acoustic source localization and classification, noise propagation in the atmosphere, and the development of new remote
Precise Temperature Measurements with Invisible LightTBMG-3513909/01/2019
A portable, stable, standards-quality radiation thermometer was invented that can measure temperatures between -50 °C (-58 °F) to 150 °C (302 °F). The corresponding infrared wavelengths are from 8 to 14 micrometers.
How Dual Polarization Technique May Improve Weather Radar on Commercial Aircraft2019-01-198206/10/2019
The airborne weather radar on a commercial aircraft is essential to ensure flight safety. It is able to detect severe weather, probable areas where presence of hail may be suspected, and thanks to its Doppler capability, the wind shears that may be dangerous when taking-off or landing. However, because it operates at X-band, the picture that it offers to the pilot may be seriously biased in situation of severe weather, in reason of the attenuation of the radar wave. The adoption of the dual pol technique in this weather radar would be most beneficial for the quality of the information delivered to the pilot for the following reasons: 1 Dual pol technique allows to operate a classification of the precipitation: distinguishing rain, melting layer, snow, hail, small ice particles. 2 Dual pol technique allows correcting the return signal for attenuation in rain. The paper aims reporting recent advances in the exploitation of dual pol radar data, based on the concept of normalisation of the
Testud, Jacques Victor, Moreau, Emmanuel, Le Bouar, Erwan
On the Safety of Autonomous Driving: A Dynamic Deep Object Detection Approach2019-01-104404/02/2019
To improve the safety of automated driving, the paramount target of this intelligent system is to detect and segment the obstacle such as car and pedestrian, precisely. Object detection in self-driving vehicle has chiefly accomplished by making decision and detecting objects through each frame of video. However, there are diverse group of methods in both machine learning and machine vision to improve the performance of system. It is significant to factor in the function of the time in the detection phase. In other word, considering the inputs of system, which have been emitted from eclectic type of sensors such as camera, radar, and LIDAR, as time-varying signals, can be helpful to engross ‘time’ as a fundamental feature in modeling for forecasting the object, while car is moving on the way. In this paper, we focus on eliciting a model through the time to increase the accuracy of object detection in self-driving vehicles. In fact, we designed a deep recurrent neural network, which is
Fekri, Pedram, Zadeh, Mehrdad, Dargahi, Javad
Measurement Technique for Continuous-Wave, Modulated, and Pulsed Monochromatic RadiationTBMG-3417704/01/2019
In many applications, such as remote sensing of atmospheric trace gases, monochromatic radiation with multiple discrete wavelengths is required. To date, there no instrument or technique that measures the wavelength jitters and fluctuations in real time.
High-Voltage Power Line Multi-Sensor SystemTBMG-3369402/01/2019
Government infrastructure facilities such as water treatment facilities, power plants, laboratories, and the like may be targets for terrorist attacks. Similarly, oil pipelines, power grids, warehouses, factories, laboratories, and the like in the commercial sector may be targeted by terrorists or persons engaging in industrial espionage and sabotage. When these facilities are remotely located, the limited or nonexistent power sources in the area may prevent or severely restrict the employment of cameras, sensors, and other intelligence, surveillance, and reconnaissance (ISR) devices. Thus, there is a need to overcome these limitations while providing around-the-clock persistent support and similar capabilities.
Portable Acousto-Optic SpectrometersTBMG-3339812/01/2018
Spectrometers are widely used for applications such as chemical analysis, remote sensing, quality control, environmental monitoring, spaceborne measurements, and optical measurements. Most spectrometers are based on using dispersive elements such as prisms, gratings, or etalons. These spectrometers typically have moving parts that induce spurious readings due to vibrations, and have limited use due to their limited spectral range and resolution capabilities, which in turn limit their use when needed for portable field applications.
A Robust Waveguide Millimeter-Wave Noise SourceTBMG-3323911/01/2018
A noise source is an enabling technology for passive millimeter-wave remote sensing applications such as atmospheric sounding, and precipitation and ice cloud measurements. NASA Goddard Space Flight Center has developed a packaged noise source that will allow calibration of the front end at the sensing frequency. This capability will eliminate or reduce the requirement of a clear view to cold space, which will reduce the mass and complexity as well as the total cost of the system.
Super-Resolution Image Reconstruction (SRIR)TBMG-3322411/01/2018
Many low-cost sensors (or cameras) may spatially or electronically under-sample an image. Similarly, cameras taking pictures from great distances, such as aerial photos, may not obtain detailed information about the subject matter. This may result in aliased images in which the high-frequency components are folded into the low-frequency components in the image. Consequently, subtle or detailed information (high-frequency components) is not present in the images.
Space Debris Orbit and Attitude Prediction for Enhanced and Efficient Space Situational AwarenessTBMG-3302510/01/2018
This research deals with the problem of modelling the orbit and attitude motion of uncontrolled manmade objects in orbit about the Earth, which tumble due to the natural influences of the near-Earth space environment. A mathematical, physics-based and computational approach is taken to model the forces and torques that drive the orbit and attitude evolution of such objects. The main influence modelled is solar radiation pressure (SRP), which is the interaction of solar electromagnetic radiation with the surface of an object, leading to both forces and torques that influence the orbital and attitude motion. Other influences, such as the gravitational field of the Earth, are also modelled.
Emission Performance of LPG Vehicles by Remote Sensing Technique in Hong Kong2018-01-182009/10/2018
Since 1st September 2014 the Hong Kong Environmental Protection Department (HKEPD) has been utilising a Dual Remote Sensing technique to monitor the emissions from gasoline and liquified petroleum gas (LPG) vehicles for identifying high emitting vehicles running on road. Remote sensing measures and determines volume ratios of the emission gases of HC, CO and NO against CO2, which are used for determining if a vehicle is a high emitter. Characterisation of each emission gas is shown and its potential to identify a high emitter is established. The data covers a total of about 2,200,000 LPG vehicle emission measurements taken from 14 different remote sensing units. It was collected from 6th January 2012 to 20th April 2017 across a period before and after the launch of the Remote Sensing programme for evaluating the performance of the programme. The results show that the HKEPD Remote Sensing programme is very effective to detect high emitting vehicles and reduce on-road vehicle emissions
Organ, Bruce D, Huang, Yuhan, Zhou, John, Hong, Guang, Yam, Yat-Shing, Chan, Edward
How to Specify Intrinsically Safe Remote Monitoring Sensor SystemsTBMG-3286609/01/2018
Wireless sensor networks frequently operate in hazardous areas where explosive atmospheres pose a safety risk to equipment and operators. The design of these systems must follow National Electrical Code (NEC), Canadian Electrical Code (CEC), and IEC/CENELEC installation requirements for Intrinsically Safe (I.S.) systems.
Remote Sensing for Smarter Forest Fire FightingTBMG-2972107/01/2018
Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
Hunting New Mining Deposits with Hyperspectral ImagingTBMG-2851303/01/2018
How much gold remains to be mined on Earth? How about the lesser-known element, indium, necessary for computer and smartphone displays? With known sources of some essential metals facing depletion within the next few decades, there is more pressure on pursuing alternatives to existing mining exploration technologies. How can we more easily find needed deposits on earth and in space?
Micro-Optomechanical Pressure Sensor Advances Pressure Monitoring in Biomedical ApplicationsTBMG-2797312/01/2017
A new type of pressure sensor is based on micro-optomechanical systems (MOMS) technology. Developed by imec, a research and innovation hub focusing on nanoelectronics and digital technologies, the sensor exhibits an excellent measurement precision in a large pressure range while being compact, resistant to electromagnetic interference (EMI), and having multiplexing capabilities. Leveraging imec's unique technical expertise in both MEMS and photonics, the sensor can be used in applications that require high-quality sensing, notably in the medical and life sciences domains.
Subjective Mapping of Dust-Emission Sources by Using MODIS ImageryTBMG-2765010/01/2017
Dust storms (5 to 100 km across) often originate from multiple dust-emission sources (1 to 10 km across). Remote-sensing-based dust-source identification is a challenge. A previous study developed a subjective approach for mapping dust sources by using enhanced MODIS satellite imagery; therefore, this study conducted mapping exercises to assess the reproducibility of this technique amongst multiple analysts and in different regions.
2.2-Micron, Uncooled, InGaAs Photodiodes and Balanced Photoreceivers up to 25-GHz BandwidthTBMG-2766310/01/2017
Traditional applications for 2-micron photodetectors have been largely dominated by passive remote sensing where detectors having bandwidth of even one megahertz are deemed sufficient. The onus in such applications is to achieve low dark current through active cooling. The advent of high-power, 2-micron-wavelength lasers has made coherent LiDARs viable for active sensing applications. Such a system needs photodetectors that can handle high local oscillator optical power and have large bandwidth. Through a combination of high coherent gain and small integration time, a large signal-to-noise ratio can be achieved. Operation at high optical power levels reduces the significance of photodiodes' dark current. As a result, uncooled operation at room temperature is feasible, simplifying the overall instrument design.
Chip-Based Power Measurement SensorTBMG-2701906/01/2017
Phone signals spend at least some time traveling over fiber-optic cables. To ensure that the information gets where it needs to go, and to help researchers find better ways to ferry this information around, it’s necessary to reliably measure radiation power through these fibers. In order to calibrate a radiation power meter, researchers currently have to use a bulky cryogenic system and transfer the measurements to at least one other intermediate system. Each of these transfers increases uncertainties in the measurements, and the cryogenic systems are relatively rare and expensive to use and maintain.
Digital Beamforming InterferometryTBMG-2702406/01/2017
NASA Goddard Space Flight Center has developed a new radar approach that uses a single phased array antenna and a single-pass configuration to generate interferograms, known as Digital Beamforming Interferometry. A digital beamforming radar system allows the implementation of nonconventional radar techniques, known as Digital Beamforming Synthetic Aperture Radar Multimode Operation (DBSAR).
Wire Sensors Detect Dangerous Conditions in the CloudsTBMG-2705706/01/2017
Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
Active Remote Sensing RadiometerTBMG-2666904/01/2017
Millimeter-wave (mm-wave) imaging techniques are already a popular solution for imaging through dust and fog. While mm-wave offers excellent penetration to dust when compared with infrared or optical sensing, the longer wavelengths create many problems associated with the specular response of surfaces at mm-wave. Generally, at mm-wave, the geometry and orientation of the target object has a larger influence on captured contrast than material properties by several orders of magnitude. While these effects can be somewhat mitigated with a radar imager, there is still a large contrast dependence on beam-target angle, and images are still entirely derived from geometry instead of material compositions.
CERTIFICATES AND SIGNATURES: How to Ensure Authentication in the IoTTBMG-2648903/01/2017
On October 21, 2016, the Internet saw a significant distributed denial of service (DDoS) attack, conducted via a botnet comprising many co-opted Internet-connected devices. The attackers of the network infrastructure were able to control these Internet-of-Things (IoT) devices for a number of reasons, including a lack of strong authentication. Loaded software turned the machines into puppets that interfered with Internet traffic for millions of users.
Researchers Turn iPhone Camera into Optical SensorTBMG-2649103/01/2017
By integrating an optical Micro-Electro-Mechanical Systems, or MEMS, chip into an iPhone camera, researchers at the VTT Technical Research Centre of Finland have developed a new, cost-effective kind of hyperspectral technology. The spectral device will provide mobile device users and consumers with new ways to monitor their environments, including quick food analysis, health checks, and other Internet-connected sensing. Research team leader Anna Rissanen works actively with companies to enable commercialization and new business development based on the team's various sensors.
2.2-Micron, Uncooled, InGaAs Photodiodes and Balanced Photoreceivers up to 25-GHz BandwidthTBMG-2646903/01/2017
Traditional applications for 2-micron photodetectors have been largely dominated by passive remote sensing where detectors having bandwidth of even one megahertz are deemed sufficient. The onus in such applications is to achieve low dark current through active cooling. The advent of high-power, 2-micron-wave-length lasers have made coherent LiDARs viable for active sensing applications. Such a system needs photodetectors that can handle high local oscillator optical power and have large bandwidth. Through a combination of high coherent gain and small integration time, a large signal-to-noise ratio can be achieved. Operation at high optical power levels reduces the significance of photodiodes’ dark current. As a result, uncooled operation at room temperature is feasible, simplifying the overall instrument design.
Mars Science Laboratory ChemCam Sun SafetyTBMG-2618601/01/2017
The Mars Science Laboratory (MSL) ChemCam instrument can be damaged when the Sun enters or passes through its field of view (FOV). There is no Sun cover, yet other instruments mounted with boresights pointing in the same direction must observe the Sun for scientific observations and for attitude determination. When in a Suntolerant focus range during rover motion and pointing for observations by other remote sensing instruments, the Sun must be allowed to pass through the ChemCam FOV, and when in a Sun-damage focus range for ChemCam observations, the Sun must never be allowed to enter the FOV, even after a rover system fault. Both of these scenarios depend upon knowledge of the attitude of the rover relative to the motion of the Sun. A Sun search that is guaranteed to be Sun-safe for the ChemCam, even when the location of the Sun is unknown, had to be developed.
Aerodynamically Stabilized Instrument PlatformTBMG-2600512/01/2016
The AeroPod, developed at NASA Goddard Space Flight Center’s Wallops Flight Facility, is a passive device that uses aerodynamic forces to stabilize an instrument package suspended from a kite or tethered blimp. The AeroPod’s design for steadying and damping payloads includes the use of a tail boom and fin combination. It is a novel design and provides a relatively simple alternative to the traditional methods for suspending equipment from kites or blimps. It is a low-altitude custom remote sensing platform craft designed for, but not limited to, agricultural and environmental research purposes. AeroPods can be used for a variety of remote sensing and in-situ observations.
Elimination of Yaw Component of Gyroscope Propagation Error During Arm Activity in MSLTBMG-2532409/01/2016
When updating attitude during arm motion, gyroscope propagation error soon becomes greater than the tilt being monitored. The solution is to add an accelerometer-only mode that can update attitude without using gyroscopes, and to add the ability to monitor pitch and roll separately. Accelerometer-only mode is used only when it is safe to assume that any vehicle shifting in yaw would also be accompanied by shifting in pitch and/or roll. For surface contact operations, it is important to monitor change in tilt of the vehicle resulting from arm motion.
3D Imaging Laser SystemTBMG-2513508/01/2016
NASA’s Goddard Space Flight Center has developed a non-scanning, 3D imaging laser system that uses a simple lens system to simultaneously generate a one-dimensional or two-dimensional array of optical (light) spots to illuminate an object, surface, or image to generate a topographic profile.
Reconfigurable Drive Current SystemTBMG-2493907/01/2016
NASA’s Marshall Space Flight Center (MSFC) has developed compact, reconfigurable electronic devices to drive and control avionics instruments. Typical avionics systems function through centralized power distribution units (PDUs), which have complex, expensive, and time-consuming design, development, test, and evaluation (DDT&E) cycles. To increase efficiency and lower design and implementation costs, the Standardized Multipurpose Avionics with Reconfigurable Technology (SMART) has been developed, replacing the PDU and sensor signal conditioning functions. By replacing the PDU, the system is able to process commands and condition signals at the application site, thus lowering system load. SMART can also be reconfigured for new tasks without changing hardware. This means functions can be added or changed later in the DDT&E cycle and even during integration, helping to reduce cost and schedule impact while enabling responsiveness to changing application needs.
Pressure Altimeter SystemsAS8009C (Current)05/24/2016
This SAE Aerospace Standard (AS) specifies minimum performance requirements for pressure altimeter systems other than air data computers. This document covers altimeter systems that measure and display altitude as a function of atmospheric pressure. The pressure transducer may be contained within the instrument display case or located remotely. Requirements for air data computers are specified in AS8002. Some requirements for nontransducing servoed altitude indicators are included in AS791. This document does not address RVSM requirements because general RVSM requirements cannot be independently detailed at the component level. The instrument system specified herein does not include aircraft pressure lines. Unless otherwise specified, whenever the term “instrument” is used, it is to be understood to be the complete system of pressure transducer components, any auxiliary equipment, and display components. The test procedures specified herein apply specifically to mechanical type
A-4 Air Data Subcommittee
2.2-Micron, Uncooled, InGaAs Photodiodes and Balanced Photoreceivers up to 25-GHz BandwidthTBMG-2458605/01/2016
Traditional applications for 2-micron photodetectors have been largely dominated by passive remote sensing where detectors having bandwidth of even one megahertz are deemed sufficient. The onus in such applications is to achieve low dark current through active cooling. The advent of high-power, 2-micron-wavelength lasers has made coherent LiDARs viable for active sensing applications. Such a system needs photodetectors that can handle high local oscillator optical power and have large bandwidth. Through a combination of high coherent gain and small integration time, a large signal-to-noise ratio can be achieved. Operation at high optical power levels reduces the significance of photodiodes’ dark current. As a result, uncooled operation at room temperature is feasible, simplifying the overall instrument design.
Disturbance-Free, High-Resolution Imaging from SpaceTBMG-2412203/01/2016
All imaging systems from space are affected by disturbances originating in the spacecraft in the form of mechanical noise from thruster and reaction/momentum wheels, and sensor noise. A drag-free system is truly unaffected by any disturbances, as it is in pure freefall. Hence, leveraging drag-free technology can provide a quantum leap in improvement for spaceborne imaging systems.
Rapid Forest Triage by Sub-Canopy Micro Air VehiclesTBMG-2408903/01/2016
Today, tree distribution maps can only be generated manually in a very time-consuming process, and real-time microclimate mapping of a large 3D volume under tree canopy is not possible. A prototype small quadrotor unmanned aerial vehicle (UAV) system was developed that is able to maneuver in cluttered environments like forests, and under tree canopy to map tree distributions from 3D point clouds gathered from an onboard stereo vision system. The UAV uses a small onboard sensor board to record micro-climate parameters during flight.
Continental-Scale Mapping of Adélie Penguin Colonies from Landsat ImageryTBMG-2411903/01/2016
The Adélie penguin has a circum-Antarctic distribution and is widely considered a useful indicator of status and change in the Antarctic and Southern Ocean ecosystems. Breeding distribution of the Adélie penguin was surveyed with Landsat-7 Enhanced Thematic Mapper Plus (ETM+) over the entire continent of Antarctica. An algorithm was designed to minimize radiometric noise and to retrieve Adélie penguin colony location and spatial extent from the ETM+ data. In all, 259 ETM+ scenes were selected from the Lansdat archive from the 1999–2003 era and were used in the retrieval. Pixel clustering identified a total of 244 individual Adélie penguin colonies, ranging in size from a single pixel (900 m2) to a maximum of 875 pixels (0.788 km2). The Landsat retrievals successfully located Adélie penguin colonies that accounted for ≈96 to 97% of the regional population used as ground truth, with errors of omission and commission on the order of only 1 to 2%.
When Sensors Mesh: How Sensor Networks Improve PerformanceTBMG-2399402/01/2016
Innovations in communications and computing hardware and software have made it easier than ever to collect minute details regarding just about any topic of interest. For technology and manufacturing interests, small, low-powered sensors can be embedded in almost any machine for data collection. Thanks to wireless technology, these embedded devices can continuously and unobtrusively provide measurements of performance and environmental data. Analysis of this data offers vast opportunities for fine-tuning performance and process.
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