ALB Evaluation for NOAA charting requirements

The National Oceanic and Atmospheric Administration (NOAA) acquires hydrographic data around the coasts of the US and its territories using in-house surveys and contracting resources. Hydrographic data are primarily collected using sonar systems, while a small percent is acquired via Airborne Lidar Bathymetry (ALB) for nearshore areas. NOAA has an ongoing requirement, as per the Coast and Geodetic Survey Act of 1947, to survey nearshore areas as part of its coastal mapping activities, including updating nautical charts, creating hydrodynamic models and supporting coastal planning and habitat mapping. NOAA has initiated a project to investigate the potential use of ALB data from non-hydrographic survey programmes (i.e., programmes designed to support objectives other than nautical charting and with specifications and requirements that differ from those of NOAA hydrographic surveys) in order to increase the amount of data available to meet these nearshore mapping requirements. THIS PAPER PRESENTS AN evaluation of ALB data from the US Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP) for use by NOAA’s Offi ce of Coast Survey (OCS). Th ese NCMP datasets were evaluated through a statistical comparison to bathymetric surfaces derived from hydrographic NOAA surveys. Th e objectives of the analysis were: 1. to assess the level of agreement between the NCMP and OCS data in areas of overlap in a variety of coastal environments and 2. to determine whether NCMP ALB survey data can be compiled with NOAA OCS hydrographic data to generate seamless shallowbathymetry digital elevation modes (DEMs)

A Review of LIDAR Radiometric Processing: From Ad Hoc Intensity Correction to Rigorous Radiometric Calibration

In addition to precise 3D coordinates, most light detection and ranging (LIDAR) systems also record “intensity”, loosely defined as the strength of the backscattered echo for each measured point. To date, LIDAR intensity data have proven beneficial in a wide range of applications because they are related to surface parameters, such as reflectance. While numerous procedures have been introduced in the scientific literature, and even commercial software, to enhance the utility of intensity data through a variety of “normalization”, “correction”, or “calibration” techniques, the current situation is complicated by a lack of standardization, as well as confusing, inconsistent use of terminology. In this paper, we first provide an overview of basic principles of LIDAR intensity measurements and applications utilizing intensity information from terrestrial, airborne topographic, and airborne bathymetric LIDAR. Next, we review effective parameters on intensity measurements, basic theory, and current intensity processing methods. We define terminology adopted from the most commonly-used conventions based on a review of current literature. Finally, we identify topics in need of further research. Ultimately, the presented information helps lay the foundation for future standards and specifications for LIDAR radiometric calibration.Keywords: calibration, normalization, radiometric, correction, intensity, LIDAR, laser scanningThis is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/sensor

Space Warps II. New Gravitational Lens Candidates from the CFHTLS Discovered through Citizen Science

We report the discovery of 29 promising (and 59 total) new lens candidates from the CFHT Legacy Survey (CFHTLS) based on about 11 million classifications performed by citizen scientists as part of the first Space Warps lens search. The goal of the blind lens search was to identify lens candidates missed by robots (the RingFinder on galaxy scales and ArcFinder on group/cluster scales) which had been previously used to mine the CFHTLS for lenses. We compare some properties of the samples detected by these algorithms to the Space Warps sample and find them to be broadly similar. The image separation distribution calculated from the Space Warps sample shows that previous constraints on the average density profile of lens galaxies are robust. SpaceWarps recovers about 65% of known lenses, while the new candidates show a richer variety compared to those found by the two robots. This detection rate could be increased to 80% by only using classifications performed by expert volunteers (albeit at the cost of a lower purity), indicating that the training and performance calibration of the citizen scientists is very important for the success of Space Warps. In this work we present the SIMCT pipeline, used for generating in situ a sample of realistic simulated lensed images. This training sample, along with the false positives identified during the search, has a legacy value for testing future lens finding algorithms. We make the pipeline and the training set publicly available.Comment: 23 pages, 12 figures, MNRAS accepted, minor to moderate changes in this versio

Space Warps: I. Crowd-sourcing the Discovery of Gravitational Lenses

We describe Space Warps, a novel gravitational lens discovery service that yields samples of high purity and completeness through crowd-sourced visual inspection. Carefully produced colour composite images are displayed to volunteers via a web- based classification interface, which records their estimates of the positions of candidate lensed features. Images of simulated lenses, as well as real images which lack lenses, are inserted into the image stream at random intervals; this training set is used to give the volunteers instantaneous feedback on their performance, as well as to calibrate a model of the system that provides dynamical updates to the probability that a classified image contains a lens. Low probability systems are retired from the site periodically, concentrating the sample towards a set of lens candidates. Having divided 160 square degrees of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) imaging into some 430,000 overlapping 82 by 82 arcsecond tiles and displaying them on the site, we were joined by around 37,000 volunteers who contributed 11 million image classifications over the course of 8 months. This Stage 1 search reduced the sample to 3381 images containing candidates; these were then refined in Stage 2 to yield a sample that we expect to be over 90% complete and 30% pure, based on our analysis of the volunteers performance on training images. We comment on the scalability of the SpaceWarps system to the wide field survey era, based on our projection that searches of 10$^5$ images could be performed by a crowd of 10$^5$ volunteers in 6 days.Comment: 21 pages, 13 figures, MNRAS accepted, minor to moderate changes in this versio

Abnormal Attention Modulation of Fear Circuit Function in Pediatric Generalized Anxiety Disorder

1. Context. Considerable work implicates abnormal neural activation and disrupted attention to facial-threat cues in adult anxiety disorders. However, in pediatric anxiety, no research has examined attention modulation of neural response to threat cues. 2. Objective. To determine whether attention modulates amygdala and cortical responses to facial threat cues differentially in adolescents with generalized anxiety disorder (GAD) and healthy adolescents. 3. Design. Case-control study. 4. Setting. Government clinical research institute. 5. Participants. Adolescent volunteers, 15 with GAD and 20 diagnosis-free. 6. Main Outcome Measure(s). Blood oxygenation level-dependent (BOLD) signal, as measured via functional magnetic resonance imaging (fMRI). During fMRI scans, participants completed a face-emotion rating task that systematically manipulated attention. 7. Results. While attending to their own subjective fear, patients, but not controls, showed greater activation to fearful than to happy faces (small volume corrected p’s \u3c .05) in a distributed network including the amygdala, ventral PFC (vPFC), and anterior cingulate cortex (ACC). Right amygdala findings appeared particularly strong. Functional connectivity analyses demonstrated positive correlations among the amygdala, vPFC, and cingulate. 8. Conclusions. Findings provide the first evidence in juveniles that GAD-associated patterns of pathological fear-circuit activation are particularly evident during certain attention states. Specifically, fear-circuit hyperactivation occurred in an attention state involving focus on subjectively-experienced fear. These findings underscore the importance of attention and its interaction with emotion in shaping function of the adolescent human fear circuit

Integrating Science Needs with Advanced Seafloor Sensor Engineering to Provide Early Warning of Geohazards: Visioning Workshop and Roadmap for the Future

The workshop was funded by the National Science Foundation (NSF), OCE Division of Ocean Sciences (Award # 1817257). This report summarizes the key findings, outcomes, and recommendations of the workshop and serves as a draft of the comprehensive roadmap

Planet Four: Probing springtime winds on Mars by mapping the southern polar CO2 jet deposits

The springtime sublimation process of Mars’ southern seasonal polar CO2 ice cap features dark fan-shaped de- posits appearing on the top of the thawing ice sheet. The fan material likely originates from the surface below the ice sheet, brought up via CO2 jets breaking through the seasonal ice cap. Once the dust and dirt is released into the atmosphere, the material may be blown by the surface winds into the dark streaks visible from orbit. The location, size and direction of these fans record a number of parameters important to quantifying seasonal winds and sublimation activity, the most important agent of geological change extant on Mars. We present results of a systematic mapping of these south polar seasonal fans with the Planet Four online citizen science project. Planet Four enlists the general public to map the shapes, directions, and sizes of the seasonal fans visible in orbital images. Over 80,000 volunteers have contributed to the Planet Four project, reviewing 221 images, from Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment) camera, taken in southern spring during Mars Years 29 and 30. We provide an overview of Planet Four and detail the processes of combining multiple volunteer assessments together to generate a high delity catalog of ∼ 400000 south polar seasonal fans. We present the results from analyzing the wind directions at several locations monitored by HiRISE over two Mars years, providing new insights into polar surface winds