Browse Topic: Terrain

Items (142)

Collection, Processing, and Accuracy of Mobile Terrestrial LiDAR Survey Data in the Coastal Environment

20AERP10_0810/01/2020

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. Army Engineer Research and Development Center (ERDC), Kitty Hawk, North Carolina Monitoring the coastline and its surroundings necessitates frequent sampling and mapping to understand the coastal processes and provide guidance for management decisions. Obstacles include continuous tide and wave influence on the morphology as well as the stability of permanent control monuments. The challenges of mapping and monitoring the coastal terrain given the dynamic nature of the system have evolved over the years, with increased spatial and temporal sampling. Early techniques relied on repeated, cross-shore transects using a survey transit and level rod. The electronic transit integrated with a distance meter (total station theodolite) increased the number of measurements. This was followed by the development of the

Use of Mass-Flux Measurement and Vapor-Phase Tomography to Quantify Vadose-Zone Source Strength and Distribution

20AERP08_1008/01/2020

Use of advanced technologies could improve evaluation of vadose zone source impacts on groundwater and vapor intrusion, leading to improved remediation decisions. Environmental Security Technology Certification Program, Alexandria, Virginia The goal of this project was to demonstrate that the multistage vapor-phase contaminant mass discharge (MS-CMD) test and vapor-phase tomography (VPT) can effectively characterize persistent volatile organic compound (VOC) sources in the vadose zone and measure their associated mass discharge. It is anticipated that these technologies will improve evaluation of vadose zone source impacts on groundwater and vapor intrusion. The U.S. Department of Defense (DoD) has focused significant effort on characterizing and treating chlorinated solvent sources in groundwater. There are two primary concerns associated with sites that contain vadose zone volatile organic compound (VOC) sources. First, discharge of contaminant vapor from the vadose zone source may

Use of Mass-Flux Measurement and Vapor-Phase Tomography to Quantify Vadose-Zone Source Strength and Distribution

TBMG-3737408/01/2020

The goal of this project was to demonstrate that the multistage vapor-phase contaminant mass discharge (MS-CMD) test and vapor-phase tomography (VPT) can effectively characterize persistent volatile organic compound (VOC) sources in the vadose zone and measure their associated mass discharge. It is anticipated that these technologies will improve evaluation of vadose zone source impacts on groundwater and vapor intrusion.

Characterizing Richness of Previously Unmapped Terrain and its Impact on Navigation Using 3D Range Sensors

TBMG-3684205/01/2020

Landers to large planetary bodies such as Mars typically use a secondary reconnaissance spacecraft to generate high-fidelity 3D terrain maps that are subsequently used for landing site selection and creating onboard maps for terrain-relative navigation systems. This luxury does not exist with small primitive bodies such as comets and asteroids. For these bodies, the landing spacecraft has to perform the 3D mapping and, with possible help from ground control, choose a feasible landing site. To enable this operation, the spacecraft would need to carry a 3D ranging sensor system such as a LiDAR. With the spacecraft placed in extended mapping orbits, 3D range measurement data is then used to create a shape model of the object. Terrain-based navigation schemes that employ cameras could then be used to image, detect, match, and track features against the map database to provide a 6-degrees-of-freedom (DOF) navigation solution during descent. Camera-based systems, however, are not robust to

EXTENSIBLE MARKUP LANGUAGE (XML) ENCODING AND COMPRESSION STANDARD

ARINC814-1 (Current)01/18/2019

ARINC 814 defines an XML encoding and compression standard for aviation. It is based on the Open Geospatial Consortium (OGC) Binary XML document. Binary XML encoding is extended in a way that is both flexible and robust. Compression is added on top of the binary encoding. ARINC 814 is expected to be used with Aeronautical Databases, in particular, ARINC Specification 813: Embedded Interchange Format for Terrain Databases, ARINC Specification 815: Embedded Interchange Format for Obstacle Databases, and ARINC Specification 816: Embedded Interchange Format for Airport Mapping Database.

Airlines Electronic Engineering Committee

EMBEDDED INTERCHANGE FORMAT FOR TERRAIN DATABASES

ARINC813 (Current)12/21/2018

This document defines an open encoding format for terrain databases. This format, when designed and implemented, will enable a quick, economic, and efficient use of Terrain Databases (TerrDBs). However, since industry does not require applications to be standardized, data interpretation is not addressed in this document.

Airlines Electronic Engineering Committee

All-Terrain Wheelchair

TBMG-2905506/01/2018

Researchers have developed an innovative design for a wheelchair that can more easily navigate on soft and uneven outdoor terrain such as grass and gravel. The chair uses three wheels — two wheels in the front (approximately the same size as the rear wheels on a traditional four-wheeled chair), and a third wheel in the back that is roughly two-thirds as tall as the front wheels.

Ride Analysis under a Random Road Model with Interval Parameters

2017-01-041503/28/2017

This work is motivated by the fact that the surface of a terrain may vary with local pavement properties and number of passes of the vehicle, which means the roughness coefficient and waviness of the terrain may vary in specific intervals. However, in traditional random terrain models, the roughness coefficient and waviness of the terrain are assumed as constants. Therefore, this assumption may be not very reasonable. A novel random terrain model is presented where the roughness coefficient and waviness of the terrain are expressed by interval numbers instead of constants. A 5-degree-of-freedom ride dynamic model of the vehicle with uncertain parameters is derived. The power spectral density (PSD) and root mean square value (RMS) of the vehicle ride responses are shown and analyzed. Analysis results indicate that the vehicle responses vary in specific intervals under the random terrain excitation with interval parameters.

Feng, Xingxing, Xu, Peijun, Fu, Penglei, Zhang, Yunqing

Off-Road Tire-Terrain Interaction: An Analytical Solution

2016-01-802909/27/2016

A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.

Papazafeiropoulos, George, Prins, Jan, Bekakos, Chrysostomos-Alexandros, O'Boy, Dan J., Mavros, George

EXTENSIBLE MARKUP LANGUAGE (XML) ENCODING AND COMPRESSION STANDARD

ARINC814 (Current)12/11/2015

ARINC 814 defines an XML encoding and compression standard for aviation. It is based on the Open Geospatial Consortium (OGC) Binary XML document. Binary XML encoding is extended in a way that is both flexible and robust. Compression is added on top of the binary encoding. ARINC 814 is expected to be used with Aeronautical Databases, and in particular, the Airport Map databases defined by ARINC 816 and the proposed ARINC Project Paper 815 Terrain and Obstacle databases.

Airlines Electronic Engineering Committee

CubeSat-Compatible, High-Resolution, Thermal Infrared Imager

07/01/2015

A small, adaptable, and stable thermal imaging system was developed that can be flown on an aircraft, deployed on the International Space Station as an attached payload, launched on a ride-share as an entirely self-contained 3U CubeSat, flown on a small satellite, or be a co-manifested satellite instrument. When the instrument design is proven, multiple copies of it could be assembled and aligned into an instrument array to enable large-swath thermal imaging from space, all to provide more detailed spatial and temporal data for biomass burning and land surface temperature studies than has heretofore been available from orbit. The instrument has an Earth-observing expected noise equivalent differential temperature (NEDT)

COTS Rugged Systems

06/01/2015

North Atlantic Industries (NAI) recently received an initial contract from L-3 Maritime Systems for Custom-on-Standard Architecture™ (COSA™) COTS rugged systems for the Ship to Shore Connector (SSC) Data Acquisition Unit. The advanced, rugged intelligent I/O and communications subsystem delivers significant advantages for data acquisition and control solutions for the U.S. Navy’s new SSC program. The SSC is the successor to the Navy’s versatile Landing Craft Air Cushion (LCAC) vehicle, which is nearing its expected service life. Prime contractor for the detail design and construction of the Ship to Shore Connector, awarded under Naval Sea Systems Command (NAVSEA) Contract N00024-12-C-2401, is Textron Systems.

Enhanced Auditory Alert Systems

TBMG-2004407/01/2014

Auditory warning systems for human interfaces are often designed around criteria that depend primarily upon signal loudness. It is well understood from the auditory literature that, by making an alert signal substantially louder than the measured background noise level, one can insure that an alert signal will be detectable. Such auditory alert systems have been used in the aviation industry for a number of years in order to raise the awareness of the crew for terrain proximity, for example. However, if an alert signal amplitude is too loud, the alert signal may produce a “startle effect” that hinders performance in some high-stress situations.

Aerospace & Defense Technology: May 2014

14AERP0505/01/2014

Simulating lightweight vehicles operating on discrete terrain Researchers characterize the mobility of autonomous reconnaissance vehicles on terrain considered to be deformable, and represented as a collection of bodies of spherical shape.

Robust Semi-Active Ride Control under Stochastic Excitation

2014-01-014504/01/2014

Ride control of military vehicles is challenging due to varied terrain and mission requirements such as operating weight. Achieving top speeds on rough terrain is typically considered a key performance parameter, which is always constrained by ride discomfort. Many military vehicles using passive suspensions suffer with compromised performance due to single tuning solution. To further stretch the performance domain to achieving higher speeds on rough roads, semi-active suspensions may offer a wide range of damping possibilities under varying conditions. In this paper, various semi-active control strategies are examined, and improvements have been made, particularly, to the acceleration-driven damper (ADD) strategy to make the approach more robust for varying operating conditions. A seven degrees of freedom ride model and a quarter-car model were developed that were excited by a random road process input modeled using an auto-regressive time series model. The proposed strategy shows

Kolansky, Jeremy, Singh, Amandeep, Goryca, Jill

Power Consumption Analysis of a Flexible-Wheel Suspension Planetary Rover Operating upon Deformable Terrain

2013-01-238409/24/2013

This study analyzes the power consumption of a specific Planetary Exploration Vehicle (PEV) subsystem known as Flexible-Wheel (FW) suspension, more specifically the interaction between a FW and the deformable terrain upon which it traverses. To achieve this a systematic and analytical calculation procedure has been developed, which culminates in the definition of three dimensionless properties to capture the FW-soil interaction. Aimed towards the design engineer participating in concept evaluation, and the control engineer conducting initial analyses, this study has found that the resistance coefficient for the interaction between a FW and the deformable terrain can, in general, be several orders of magnitude higher than the rolling resistance of a pneumatic tire operating upon rigid terrain. The sensitivity analyses also unveiled certain design parameters which have much more effect on the resistance coefficient than others, enabling the engineer to concentrate their efforts more

Jesson, Peter, Cao, Dongpu

Using Performance Margin and Dynamic Simulation for Location Aware Adaptation of Vehicle Dynamics

2013-01-070304/08/2013

One seminal question that faces a vehicle's driver (either human or computer) is predicting the capability of the vehicle as it encounters upcoming terrain. A Performance Margin (PM) is defined in this work as the ratio of the required tractive effort to the available tractive effort for the front and rear respectively. This simple definition stems from and incorporates many traditional handling metrics and is robust in its scope of applicability. The PM is implemented in an Intervention Strategy demonstrating its use to avoid situations in which the vehicle exceeds its handling capabilities. Results from a design case study are presented to show the potential efficacy of developing a PM-based control system.

Matthews, Cullen C., Cho, Sukhwan, Ferris, John, Schlinkheider, Joerg, Montgomery, Matthew

Developing a Compact Continuous-State Markov Chain for Terrain Road Profiles

2013-01-062904/08/2013

Accurate terrain models provide the chassis designer with a powerful tool to make informed design decisions early in the design process. It is beneficial to characterize the terrain as a stochastic process, allowing limitless amounts of synthetic terrain to be created from a small number of parameters. A continuous-state Markov chain is proposed as an alternative to the traditional discrete-state chain currently used in terrain modeling practice. For discrete-state chains, the profile transitions are quantized then characterized by a transition matrix (with many values). In contrast, the transition function of a continuous-state chain represents the probability density of transitioning between any two states in the continuum of terrain heights. The transition function developed in this work uses a location-scale distribution with polynomials modeling the parameters as functions of the current state. A maximum likelihood estimator is used to parameterize the coefficients of these

Lambeth, Jacob N., Ferris, John, Reid, Alexander, Gorsich, David

Regolith Advanced Surface Systems Operations Robot Excavator

TBMG-1547101/01/2013

The Regolith Advanced Surface Systems Operations Robot (RASSOR) excavator robot is a teleoperated mobility platform with a space regolith excavation capability. This more compact, lightweight design (

Wind-Driven Wireless Networked System of Mobile Sensors for Mars Exploration

TBMG-1547401/01/2013

A revolutionary way is proposed of studying the surface of Mars using a wind-driven network of mobile sensors: GOWON. GOWON would be a scalable, self-powered and autonomous distributed system that could allow in situ mapping of a wide range of environmental phenomena in a much larger portion of the surface of Mars compared to earlier missions. It could improve the possibility of finding rare phenomena such as “blueberries” or bio-signatures and mapping their occurrence, through random wind-driven search. It would explore difficult terrains that were beyond the reach of previous missions, such as regions with very steep slopes and cluttered surfaces. GOWON has a potentially long life span, as individual elements can be added to the array periodically. It could potentially provide a costeffective solution for mapping wide areas of Martian terrain, enabling leaving a long-lasting sensing and searching infrastructure on the surface of Mars.

Using Multispectral Imaging for Ecological Observations

TBMG-1536112/01/2012

With an airborne camera capable of making precise and detailed ecological observations, biologists at Applied Ecological Services (Brodhead, WI) are bringing satellite imagery closer to earth.

Image Sensors Enable Curiosity to Capture High-Definition Images From Mars

TBMG-1535812/01/2012

The Mars Science Laboratory rover, Curiosity, is designed to assess whether Mars ever had an environment able to support life by deploying the most advanced set of scientific instruments ever sent to the planet. As part of that instrument suite, all four science cameras on the rover are designed using image sensors from Truesense Imaging to capture high-resolution color images of the planet.

A Distributive, Non-Destructive, Real-Time Approach to Snowpack Monitoring

TBMG-1527012/01/2012

This invention is designed to ascertain the snow water equivalence (SWE) of snowpacks with better spatial and temporal resolutions than present techniques. The approach is ground-based, as opposed to some techniques that are air-based. In addition, the approach is compact, non-destructive, and can be communicated with remotely, and thus can be deployed in areas not possible with current methods.

Autonomous Rover Traverse and Precise Arm Placement on Remotely Designated Targets

TBMG-1466609/01/2012

This software controls a rover platform to traverse rocky terrain autonomously, plan paths, and avoid obstacles using its stereo hazard and navigation cameras. It does so while continuously tracking a target of interest selected from 10–20 m away. The rover drives and tracks the target until it reaches the vicinity of the target. The rover then positions itself to approach the target, deploys its robotic arm, and places the end effector instrument on the designated target to within 2–3-cm accuracy of the originally selected target.

Large Terrain Continuous Level of Detail 3D Visualization Tool

TBMG-1468009/01/2012

This software solved the problem of displaying terrains that are usually too large to be displayed on standard workstations in real time. The software can visualize terrain data sets composed of billions of vertices, and can display these data sets at greater than 30 frames per second.

Vision-Aided Autonomous Landing and Ingress of Micro Aerial Vehicles

TBMG-1462509/01/2012

Micro aerial vehicles have limited sensor suites and computational power. For reconnaissance tasks and to conserve energy, these systems need the ability to autonomously land at vantage points or enter buildings (ingress). But for autonomous navigation, information is needed to identify and guide the vehicle to the target. Vision algorithms can provide egomotion estimation and target detection using input from cameras that are easy to include in miniature systems.

Water Detection Based on Color Variation

TBMG-1387906/01/2012

This software has been designed to detect water bodies that are out in the open on cross-country terrain at close range (out to 30 meters), using imagery acquired from a stereo pair of color cameras mounted on a terrestrial, unmanned ground vehicle (UGV). This detector exploits the fact that the color variation across water bodies is generally larger and more uniform than that of other naturally occurring types of terrain, such as soil and vegetation. Non-traversable water bodies, such as large puddles, ponds, and lakes, are detected based on color variation, image intensity variance, image intensity gradient, size, and shape.

DspaceOgreTerrain 3D Terrain Visualization Tool

TBMG-1387706/01/2012

DspaceOgreTerrain is an extension to the DspaceOgre 3D visualization tool that supports real-time visualization of various terrain types, including digital elevation maps, planets, and meshes. DspaceOgreTerrain supports creating 3D representations of terrains and placing them in a scene graph. The 3D representations allow for a continuous level of detail, GPU-based rendering, and overlaying graphics like wheel tracks and shadows. It supports reading data from the SimScape terrain-modeling library.

Lunar Navigation Determination System — LaNDS

TBMG-1327204/01/2012

A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS — Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors.

Lunar Navigation Determination System — LaNDS

TBMG-TB-01327204/01/2012

A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS — Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors.

3D Visualization for Phoenix Mars Lander Science Operations

TBMG-1303603/01/2012

Planetary surface exploration missions present considerable operational challenges in the form of substantial communication delays, limited communication windows, and limited communication bandwidth. A 3D visualization software was developed and delivered to the 2008 Phoenix Mars Lander (PML) mission. The components of the system include an interactive 3D visualization environment called “Mercator,” terrain reconstruction software called the “Ames Stereo Pipeline,” and a server providing distributed access to terrain models. The software was successfully utilized during the mission for science analysis, site understanding, and science operations activity planning.

Lidar Luminance Quantizer

TBMG-1224212/01/2011

This innovation addresses challenges in lidar imaging, particularly with the detection scheme and the shapes of the detected signals. Ideally, the echoed pulse widths should be extremely narrow to resolve fine detail at high event rates. However, narrow pulses require wideband detection circuitry with increased power dissipation to minimize thermal noise. Filtering is also required to shape each received signal into a form suitable for processing by a constant fraction discriminator (CFD) followed by a time-to-digital converter (TDC). As the intervals between the echoes decrease, the finite bandwidth of the shaping circuits blends the pulses into an analog signal (luminance) with multiple modes, reducing the ability of the CFD to discriminate individual events.

In Situ Surface Characterization

TBMG-1222812/01/2011

Operation of in situ space assets, such as rovers and landers, requires operators to acquire a thorough understanding of the environment surrounding the spacecraft. The following programs help with that understanding by providing higherlevel information characterizing the surface, which is not immediately obvious by just looking at the XYZ terrain data. This software suite covers three primary programs: marsuvw, marsrough, and marsslope, and two secondary programs, which together use XYZ data derived from in situ stereo imagery to characterize the surface by determining surface normal, surface roughness, and various aspects of local slope, respectively.

New Video Documents Three-Year Trek by Mars Rover

TBMG-1221211/28/2011

A new video compiles 309 images taken by NASA’s Mars Exploration Rover Opportunity, providing an historic record of a three-year trek that totaled about 13 miles across a Martian plain pocked with smaller craters.

Surface Modeling to Support Small-Body Spacecraft Exploration and Proximity Operations

TBMG-1189211/01/2011

In order to simulate physically plausible surfaces that represent geologically evolved surfaces, demonstrating demanding surface-relative guidance navigation and control (GN&C) actions, such surfaces must be made to mimic the geological processes themselves. A report describes how, using software and algorithms to model body surfaces as a series of digital terrain maps, a series of processes was put in place that evolve the surface from some assumed nominal starting condition.

Coastal On-line Assessment and Synthesis Tool 2.0

TBMG-1093709/01/2011

COAST (Coastal On-line Assessment and Synthesis Tool) is a 3D, open-source Earth data browser developed by leveraging and enhancing previous NASA open-source tools. These tools use satellite imagery and elevation data in a way that allows any user to zoom from orbit view down into any place on Earth, and enables the user to experience Earth terrain in a visually rich 3D view. The benefits associated with taking advantage of an open-source geo-browser are that it is free, extensible, and offers a worldwide developer community that is available to provide additional development and improvement potential.

Coastal On-line Assessment and Synthesis Tool 2.0

TBMG-TB-01093709/01/2011

COAST (Coastal On-line Assessment and Synthesis Tool) is a 3D, open-source Earth data browser developed by leveraging and enhancing previous NASA open-source tools. These tools use satellite imagery and elevation data in a way that allows any user to zoom from orbit view down into any place on Earth, and enables the user to experience Earth terrain in a visually rich 3D view. The benefits associated with taking advantage of an open-source geo-browser are that it is free, extensible, and offers a worldwide developer community that is available to provide additional development and improvement potential.

INTEGRATED SURVEILLANCE SYSTEM

ARINC768-2 (Current)06/01/2011

This document defines an Integrated Surveillance System (ISS) capable of providing traffic, terrain and weather information to the flight deck crew. Supplement 2 provides enhancements in the traffic surveillance area to support ADS-B Out and ADS-B In functionality, ADS-Re-broadcast capability, and Traffic Information Services Broadcast (TIS-B).

Airlines Electronic Engineering Committee

Multi-Modal Image Registration and Matching for Localization of a Balloon on Titan

TBMG-945203/01/2011

A solution was developed that matches visible/IR imagery aboard a balloon in Saturn’s moon Titan’s atmosphere to SAR (synthetic aperture radar) and visible/IR data acquired from orbit. A balloon in Titan’s atmosphere must be able to localize itself autonomously both globally and with respect to local terrain. The orbital data is used to provide the balloon imagery with global context.

Intake System Design Approach for Turbocharged MPFI SI Engine

2011-26-000101/19/2011

The automotive industry is currently facing the challenge of significantly stringent requirements regarding CO₂ emission and fuel economy coming from both legislations and customer demand. Advanced engine technologies play a vital role for downsizing of gasoline engine. The development of key design technologies for high efficiency gasoline engines is required for the improvement of competitive power in the global automobile industry. This paper focused on effect of geometry of intake manifold of gas exchange process and consequently the performance of the engine. Specially, the optimal design technologies for the intake manifold and intake port shape must be established for high performance, increasingly stringent fuel economy and emission regulations. Space in vehicle or packaging constraints and cost are also important factors while consideration of the design. Two models of intake manifolds discussed in this paper, such as short runner intake manifold and long runner intake

Jagtap, Harishchandra, Vinayak, Chavan, Koli, Ravindra

Visual SLAM Using Variance Grid Maps

TBMG-902601/01/2011

An algorithm denoted “Gamma-SLAM” performs further processing, in real time, of preprocessed digitized images acquired by a stereoscopic pair of electronic cameras aboard an off-road robotic ground vehicle to build accurate maps of the terrain and determine the location of the vehicle with respect to the maps. Part of the name of the algorithm reflects the fact that the process of building the maps and determining the location with respect to them is denoted “simultaneous localization and mapping” (SLAM). Most prior real-time SLAM algorithms have been limited in applicability to (1) systems equipped with scanning laser range finders as the primary sensors in (2) indoor environments (or relatively simply structured outdoor environments). The few prior vision-based SLAM algorithms have been feature-based and not suitable for real-time applications and, hence, not suitable for autonomous navigation on irregularly structured terrain.

An Augmentation of G-Guidance Algorithms

TBMG-903001/01/2011

The original G-Guidance algorithm provided an autonomous guidance and control policy for small-body proximity operations that took into account uncertainty and dynamics disturbances. However, there was a lack of robustness in regards to object proximity while in autonomous mode. The modified G-Guidance algorithm was augmented with a second operational mode that allows switching into a safety hover mode. This will cause a spacecraft to hover in place until a mission-planning algorithm can compute a safe new trajectory. No state or control constraints are violated. When a new, feasible state trajectory is calculated, the spacecraft will return to standard mode and maneuver toward the target. The main goal of this augmentation is to protect the spacecraft in the event that a landing surface or obstacle is closer or further than anticipated. The algorithm can be used for the mitigation of any unexpected trajectory or state changes that occur during standard mode operations.

Mars Terrain Generation

TBMG-889812/01/2010

A suite of programs for the generation of disparity maps from stereo image pairs via correlation, and conversion of those disparity maps to XYZ maps, has been updated. This suite implements an automated method of deriving terrain from stereo images for use in the ground data system for in-situ (lander and rover) cameras. This differs from onboard correlation by concentrating more on accuracy than speed, since near-real-time is not a requirement on the ground. The final result is an XYZ value for every point in the image that passes several quality checks. A priori geometric camera calibration information is required for this suite to operate.

Predicting Long-Range Traversability From Short-Range Stereo-Derived Geometry

TBMG-868511/01/2010

Based only on its appearance in imagery, this program uses close-range 3D terrain analysis to produce training data sufficient to estimate the traversability of terrain beyond 3D sensing range. This approach is called learning from stereo (LFS). In effect, the software transfers knowledge from middle distances, where 3D geometry provides training cues, into the far field where only appearance is available. This is a viable approach because the same obstacle classes, and sometimes the same obstacles, are typically present in the mid-field and the far-field. Learning thus extends the effective look-ahead distance of the sensors.

Predicting Long-Range Traversability From Short-Range Stereo-Derived Geometry

TBMG-TB-00868511/01/2010

Learning-based software improves obstacle avoidance by robotic ground vehicles. Based only on its appearance in imagery, this program uses close-range 3D terrain analysis to produce training data sufficient to estimate the traversability of terrain beyond 3D sensing range. This approach is called learning from stereo (LFS). In effect, the software transfers knowledge from middle distances, where 3D geometry provides training cues, into the far field where only appearance is available. This is a viable approach because the same obstacle classes, and sometimes the same obstacles, are typically present in the mid-field and the far-field. Learning thus extends the effective look-ahead distance of the sensors.

Water Detection Based on Sky Reflections

TBMG-843109/01/2010

This software has been designed to detect water bodies that are out in the open on cross-country terrain at mid- to far-range (approximately 20–100 meters), using imagery acquired from a stereo pair of color cameras mounted on a terrestrial, unmanned ground vehicle (UGV). Non-traversable water bodies, such as large puddles, ponds, and lakes, are indirectly detected by detecting reflections of the sky below the horizon in color imagery. The appearance of water bodies in color imagery largely depends on the ratio of light reflected off the water surface to the light coming out of the water body. When a water body is far away, the angle of incidence is large, and the light reflected off the water surface dominates. We have exploited this behavior to detect water bodies out in the open at mid- to far-range. When a water body is detected at far range, a UGV’s path planner can begin to look for alternate routes to the goal position sooner, rather than later. As a result, detecting water

JMISR INteractive eXplorer

TBMG-843309/01/2010

MISR (Multi-angle Imaging SpectroRadiometer) INteractive eXplorer (MINX) is an interactive visualization program that allows a user to digitize smoke, dust, or volcanic plumes in MISR multiangle images, and automatically retrieve height and wind profiles associated with those plumes. This innovation can perform 9-camera animations of MISR level-1 radiance images to study the 3D relationships of clouds and plumes. MINX also enables archiving MISR aerosol properties and Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power along with the heights and winds. It can correct geometric misregistration between cameras by correlating off-nadir camera scenes with corresponding nadir scenes and then warping the images to minimize the misregistration offsets. Plots of BRF (bidirectional reflectance factor) vs. camera angle for points clicked in an image can be displayed. Users get rapid access to map views of MISR path and orbit locations and overflight dates, and past or

Autonomous Exploration for Gathering Increased Science

TBMG-844209/01/2010

The Autonomous Exploration for Gathering Increased Science System (AEGIS) provides automated targeting for remote sensing instruments on the Mars Exploration Rover (MER) mission, which at the time of this reporting has had two rovers exploring the surface of Mars (see figure). Currently, targets for rover remote-sensing instruments must be selected manually based on imagery already on the ground with the operations team. AEGIS enables the rover flight software to analyze imagery onboard in order to autonomously select and sequence targeted remote-sensing observations in an opportunistic fashion. In particular, this technology will be used to automatically acquire sub-framed, high-resolution, targeted images taken with the MER panoramic cameras.

Simplified Vicarious Radiometric Calibration

TBMG-831008/01/2010

A measurement-based radiance estimation approach for vicarious radiometric calibration of spaceborne multispectral remote sensing systems has been developed. This simplified process eliminates the use of radiative transfer codes and reduces the number of atmospheric assumptions required to perform sensor calibrations. Like prior approaches, the simplified method involves the collection of ground truth data coincident

Launchable and Retrievable Tetherobot

TBMG-808106/01/2010

A proposed robotic system for scientific exploration of rough terrain would include a stationary or infrequently moving larger base robot, to which would be tethered a smaller hopping robot of the type described in the immediately preceding article. The two-robot design would extend the reach of the base robot, making it possible to explore nearby locations that might otherwise be inaccessible or too hazardous for the base robot.

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