Browse Topic: Remote sensing

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IAQG-1 Standards Committee
Joint Calibration of Dual LiDARs and Camera Using a Circular Chessboard2020-01-00984/14/2020
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 laboratory. Meanwhile, we propose the related joint calibration method using a circular chessboard. The center of circular chessboard is respectively detected in camera image to get pixel coordinates and in point cloud of LiDAR to get 3D coordinates. The calibration problem is then converted into a 3D-2D PnP matching problem and the center of the chessboard is set as corresponding points to construct the geometric constraints to get initial calibration values. Further, a proper global loss function is elaborately designed for Levenberg-Marquardt nonlinear optimization to obtain the final calibration parameters, and then the extrinsic parameters between any two sensors are estimated simultaneously. Experimental results show that the proposed method is suitable for the joint calibration of fusion system composed of LiDARs and camera, and the calibration results have high accuracy and stability.
Deng, Zhenwen, Xiong, Lu, Yin, Dong, Shan, Fengwu
Magneto-Optic Biosensor Using Bio-Functionalized Magnetic NanoparticlesTBMG-358271/1/2020
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 201919AERP1010/1/2019
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 vehicle components. SnowMicroPenetrometer Applications for Winter Vehicle Mobility Characterizing the mechanical properties of snow and their impact on vehicle performance could improve vehicle winter mobility modeling. Engineered Resilient Systems A new application called TradeAnalyzer provides multiple visualization methods to examine, sort, and filter the attributes of data.
Green's Function Extraction from Atmospheric Acoustic Propagation19AERP10_0810/1/2019
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 sensing techniques of the atmosphere. By extracting the medium impulse response, or Green's function, one may obtain information about the medium channel in order to overcome the medium effects or deduce information about the medium. For example, in acoustic communications, information is sent through a medium from a host station to client stations. The transmitted information is subjected to a variety of signal distortions and noise caused by the medium. Using time-reversal processing, it is possible to extract the channel medium impulse response from the transmission of a known pilot signal through the channel medium. This Green's function was then used to modify the subsequent signals to overcome distortion in the channel.
Green’s Function Extraction from Atmospheric Acoustic PropagationTBMG-3536310/1/2019
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.
Precise Temperature Measurements with Invisible LightTBMG-351399/1/2019
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 Aircraft2019-01-19826/10/2019
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 particle size distribution (PSD) and on ZPHI® algorithm for precipitation retrieval. Their combination helps retrieving parameter N0* able to represent alone the variability of the PSD, for rain or ice particles whatever. The main interest of the combination between dual pol radar and ZPHI® software for inflight application is: To be able to measure ice concentration in altitude by implementing a new version of ZPHI® describing the along beam N0* evolution, in order to interpret the radar reflectivity in terms of ice particle concentration; To be able to calibrate the radar using self-consistency of polarimetric variables.
Testud, Jacques Victor, Moreau, Emmanuel, Le Bouar, Erwan
On the Safety of Autonomous Driving: A Dynamic Deep Object Detection Approach2019-01-10444/2/2019
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 fed by the output of a deep convolutional neural network. Eventually, the proposed system could make a decision about each front vehicle not only by utilizing the data during a predefined span of the video, but also enhance the performance of system to determine the object as whether a car or not. Results shows that the performance of system compared to convolutional neural network based vehicle detector, is more precise in the case of discerning cars.
Fekri, Pedram, Zadeh, Mehrdad, Dargahi, Javad
Measurement Technique for Continuous-Wave, Modulated, and Pulsed Monochromatic RadiationTBMG-341774/1/2019
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-336942/1/2019
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-3339812/1/2018
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-3323911/1/2018
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-3322411/1/2018
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-3302510/1/2018
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.
How to Specify Intrinsically Safe Remote Monitoring Sensor SystemsTBMG-328669/1/2018
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-297217/1/2018
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-285133/1/2018
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-2797312/1/2017
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-2765010/1/2017
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-2766310/1/2017
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.
Wire Sensors Detect Dangerous Conditions in the CloudsTBMG-270576/1/2017
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.
Digital Beamforming InterferometryTBMG-270246/1/2017
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).
Chip-Based Power Measurement SensorTBMG-270196/1/2017
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.
Active Remote Sensing RadiometerTBMG-266694/1/2017
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-264893/1/2017
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-264913/1/2017
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-264693/1/2017
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-261861/1/2017
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-2600512/1/2016
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-253249/1/2016
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-251358/1/2016
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-249397/1/2016
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)5/24/2016
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 instruments. Solid state instruments or automatic test instrumentation may require other test procedures. Such differing procedures shall be justified prior to use.
A-4 Air Data Subcommittee
2.2-Micron, Uncooled, InGaAs Photodiodes and Balanced Photoreceivers up to 25-GHz BandwidthTBMG-245865/1/2016
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.
Rapid Forest Triage by Sub-Canopy Micro Air VehiclesTBMG-240893/1/2016
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-241193/1/2016
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%.
Disturbance-Free, High-Resolution Imaging from SpaceTBMG-241223/1/2016
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.
When Sensors Mesh: How Sensor Networks Improve PerformanceTBMG-239942/1/2016
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.
Generating a Laser Linear Frequency Modulation Waveform for Application in Coherent Doppler LidarTBMG-238572/1/2016
Frequency modulation of a single-frequency laser with a linear triangular waveform is of great interest to many laser remote sensing and interferometry applications. Linear frequency modulation of a continuous-wave (CW) laser beam can make target distance measurements with great precision. If the frequency modulation is perfectly linear with time, such a laser radar (lidar) system will have higher resolution and accuracy compared with pulsed lasers.
Multiple-Frequency-Band Software-Defined RadiometerTBMG-236551/1/2016
Remote sensing — the use of spacebased satellite technologies to obtain information on environmental variables — in combination with other types of data, can provide information on changes in the Earth’s surface and atmosphere that are critical for weather forecasting and responding to human welfare issues (disease outbreaks, food shortages, and floods). Satellites and other remote sensing tools have gathered a great deal of useful data on the Earth’s climate systems, drainage systems, geologic structures, thermal anomalies, geomorphologic features, and distribution of vegetation.
Using Black Polyimide/Kevlar as a Metering Structure Multi-Layer Insulation (MLI)TBMG-2321211/1/2015
Metering structures of remote sensing instruments often have large openings or access holes. Shear panels that are X-shaped, such as those proposed for the Neutron Star Interior Composition Explorer (NICER), generally consist of C-channels and L-brackets to minimize structural distortion. This type of metering structure has large openings on the sides. Structural panels that have large access holes, such as those studied for the Landsat Operational Land Imager (OLI), generally consist of aluminum honeycomb panels with composite facesheets. Both types of metering structure require multilayer insulation (MLI) blankets to shield the internal components such as optics from sunlight and Earth albedo, and to minimize heat loss to 3K space by radiation. The issues of conventional MLI blankets for these metering structures include MLI sagging, stray light, and risk of micrometeoroid damage to optics.
An Overview of Data Transmission Used in UAVs for Remote Sensing Surveillance and Environmental Management Systems2015-36-05439/22/2015
The increasing development of Unmanned Aerial Vehicle (UAV) technologies has allowed greater use of UAVs as remote sensing platforms to enhance satellite and manned aerial vehicle remote sensing surveillance and environmental management systems. Particularly, the Brazilian National Institute for Space Research - INPE has an Environmental Data Collection System (SCD) since 1993. Recently, the MCTI (Ministry of Science, Technology and Innovation) opened the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN). Both may need additional resources for their expansions in the near future as offered by UAV technologies. These needs illustrate the potential of UAV technologies as complement to existing or future systems. This paper presents an overview of data transmission used in UAVs for remote sensing surveillance and environmental management systems. This includes post-disaster assessment, environmental management and monitoring of infrastructure development with emphasis on imagery data communication system between the users and the aerial vehicle - link via satellite, available mobile communication networks and direct line of sight. Modulation types and allocated frequency bands for these applications are presented. These allows an image data signal captured by the surveillance camera be either displayed on the terminals in real time, or stored on ground for future off-line analysis. So, this overview aims to contribute to the expansion of current and future remote sensing surveillance and environmental management systems in Brazil using UAV technologies.
da Silva Araujo, Rodolfo Antonio, Rodrigues, José Antonio, de Oliveira e Souza, Marcelo Lopes
Visual Environment for Remote Virtual Exploration (VERVE) v2TBMG-228619/1/2015
VERVE is a 3D visualization system that provides situational awareness, science analysis tools, and data understanding capabilities for robotics researchers and exploration science operations. VERVE includes telemetry views that show remote system status, and can be extended to support various types of robots. VERVE is highly modular, extensible, and includes a 3D scenegraph database, interactive 3D viewer, and associated graphical user interfaces (GUIs) to OSGI (Java standards organization) plug-in based applications.
Domain-Engineered Magnesium-Oxide-Doped Lithium Niobate for Lidar-Based Remote SensingTBMG-224287/1/2015
There are several frequency conversion applications associated with lidar-based remote sensing that would benefit from the use of high-quality, complex (i.e., chirped, multi-section, or otherwise modulated) domain-engineered magnesiumoxide- doped lithium niobate (MgO:LN). While congruently melting lithium niobate (CLN) has been explored in detail over the last decades, it is known to be highly susceptible to photorefractive damage, which has limited the achievable performance of some QPM-assisted (quasi phase matching) structures that are commercially available. The demand for high-performance engineered nonlinear optical (NLO) materials, in terms of power handling, efficiency, conversion bandwidth, and accessible wavelength range, has driven the development of high-quality, large-area wafers of MgO:LN. While commercial outlets for these materials exist, there is still a need to expand the achievable performance of these structures (i.e. larger aperture bulk structures, higher efficiency waveguide structures, and implementation of sophisticated poling designs that increase achievable conversion bandwidths).
Initial Results from Radiometer and Polarimetric Radar-based Icing Algorithms Compared to In-situ Data2015-01-21536/15/2015
In early 2015, a field campaign was conducted at the NASA Glenn Research Center in Cleveland, Ohio, USA. The purpose of the campaign is to test several prototype algorithms meant to detect the location and severity of in-flight icing (or icing aloft, as opposed to ground icing) within the terminal airspace. Terminal airspace for this project is currently defined as within 25 kilometers horizontal distance of the terminal, which in this instance is Hopkins International Airport in Cleveland. Two new and improved algorithms that utilize ground-based remote sensing instrumentation have been developed and were operated during the field campaign. The first is the ‘NASA Icing Remote Sensing System’, or NIRSS. The second algorithm is the ‘Radar Icing Algorithm’, or RadIA. In addition to these algorithms, which were derived from ground-based remote sensors, in-situ icing measurements of the profiles of supercooled liquid water (SLW) collected with vibrating wire sondes attached to weather balloons produced a comprehensive database for comparison. Key fields from the SLW-sondes include air temperature, humidity and liquid water content, cataloged by time and 3-D location. This work gives an overview of the NIRSS and RadIA products and results are compared to in-situ SLW-sonde data from one icing case study. The location and quantity of supercooled liquid as measured by the insitu probes provide a measure of the utility of these prototype hazard-sensing algorithms.
Serke, David, King, Michael, Reehorst, Andrew
Aircraft In Situ Validation of Hydrometeors and Icing Conditions Inferred by Ground-based NEXRAD Polarimetric Radar2015-01-21526/15/2015
MIT Lincoln Laboratory is tasked by the U.S. Federal Aviation Administration to investigate the use of the NEXRAD polarimetric radars* for the remote sensing of icing conditions hazardous to aircraft. A critical aspect of the investigation concerns validation that has relied upon commercial airline icing pilot reports and a dedicated campaign of in situ flights in winter storms. During the month of February in 2012 and 2013, the Convair-580 aircraft operated by the National Research Council of Canada was used for in situ validation of snowstorm characteristics under simultaneous observation by NEXRAD radars in Cleveland, Ohio and Buffalo, New York. The most anisotropic and easily distinguished winter targets to dual pol radar are ice crystals. Accordingly, laboratory diffusion chamber measurements in a tightly-controlled parameter space of temperature and humidity provide the linkage between shape and the expectation for the presence/absence of water saturation conditions necessary for icing hazard in situ. In agreement with the laboratory measurements pertaining to dendritic and hexagonal flat plate crystals, the aircraft measurements have verified the presence of supercooled water in mainly low concentrations coincident with regions showing layered anomalies of positive differential reflectivity (ZDR) by ground-based radar, otherwise known as +ZDR ‘bright bands’. Extreme values of ZDR (up to +8 dB) have also been found to be coincident with hexagonal flat plate crystals and intermittent supercooled water, also consistent with laboratory measurements. The icing conditions found with the anisotropic description are considered non-classical (condensation/collision-coalescence) and require the ascent of air and availability of ice nuclei. A modest ascent rate (<1 m/s) is needed for preservation of the anisotropic ice crystal shapes, making them identifiable to dual-pol radar. In the other limit of strong ascent (several m/s and greater), a vigorous riming process is present leading to graupel and hail, and with attendant radar reflectivity of 30 dBZ and greater. These rimed hydrometeors are also readily verified by dual pol hydrometeor classification and in situ aircraft measurements. For the intermediate level of ascent speed, snow can become rimed, diluting its anisotropy, and presents a challenge to unambiguous detection of an icing condition by dual pol radar. This challenge is under current study.
Williams, Earle, Donovan, Michael F., Smalley, David J., Hallowell, Robert G., Griffin, Elaine P., Hood, Kenta T., Bennett, Betty J., Wolde, Mengistu, Korolev, Alexei V.
Improved Calibration Shows Images’ True ColorsTBMG-222576/1/2015
In satellite images, the true color of a body of water, or anything else they depict, is not precise. Radiometric calibration, which improves the color accuracy of an image and enables it to be used to solve remote sensing problems, has always been a costly endeavor. A cooperative effort between Stennis Space Center and Innovative Imaging and Research Corporation (I2R), a small business located on the center’s campus in southern Mississippi, is changing that.
Neo-Geography Toolkit (NGT) v2TBMG-221766/1/2015
The Neo-Geography Toolkit (NGT) is a collection of open-source software tools for the automated processing of geospatial data, including images and maps. It can process raw raster data from remote sensing instruments and transform it into useful cartographic products such as visible image base maps, topographic models, etc. It can also perform data processing on extremely large geospatial data sets (up to several tens of terabytes) via parallel processing pipelines. Finally, it can transform raw metadata, vector data, and geo-tagged datasets into standard Neo-Geography data formats such as KML.
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