Carl J Legleiter
(He/him)Carl joined the U.S. Geological Survey in 2016 and has a Ph.D. in Geography from the University of California Santa Barbara.
As a member of the USGS Water Resources Mission Area Hydrologic Remote Sensing Branch, Carl conducts research on remote sensing of rivers, specifically retrieval of depth, velocity, and other channel attributes from various types of image data. Current efforts are focused on the development and testing of methods for estimating surface flow velocities from videos and image time series acquired from Uncrewed Aircraft Systems (UAS, or drones), helicopters, and moving aircraft. In addition, he is actively involved in ongoing studies seeking to advance our ability to characterize potentially harmful algal blooms (HABs) via hyperspectral imaging. Another topic of continued interest is a collaborative project with the USGS Ecosystems Mission Area to assess habitat for pallid sturgeon on the Missouri River by conducting tracer experiments. This study involves estimating concentrations of the tracer dye from remotely sensed data to better understand dispersion processes operating within the river.
Professional Experience
2016-present: Research Hydrologist, USGS Water Resources Mission Area, Hydrologic Remote Sensing Branch
2015-2016: Associate Professor, Geography, University of Wyoming
2009-2015: Assistant Professor, Geography, University of Wyoming
2009-2015: Faculty Affiliate and volunteer, USGS Geomorphology & Sediment Transport Laboratory
2009: Hydrologist, USGS Geomorphology & Sediment Transport Laboratory
2004-2006: Graduate Student Assistant, San Joaquin District River Management Section, California Department of Water Resources
Education and Certifications
B.S. – Earth Sciences, Montana State University, Bozeman, Montana (2002)
B.S. – Mathematical Sciences, Montana State University, Bozeman, Montana (2002)
M.A. – Geography, UC Santa Barbara, Santa Barbara, California (2004)
Ph.D. – Geography, UC Santa Barbara, Santa Barbara, California (2008)
Science and Products
Site visit cross section surveys and multispectral image data from gaging stations throughout the Willamette and Delaware River Basins from 2022 and code for Bathymetric Mapping using Gage Records and Image Databases (BaMGRID)
Helicopter-based videos and orthomosaic maps produced for Integrated Water Science basin riverine study sites, 2022
Video acquired from an Uncrewed Aerial System, UAS, and hydroacoustic measurements of flow velocity obtained along the North Santiam River, Oregon, in July 2022
Remotely sensed data from a reach of the Sacramento River near Glenn, California, used to perform Particle Image Velocimetry (PIV) within the Robot Operating System (ROS)
Hydrodynamic model output and image simulation code for evaluating image-based river velocimetry from a case study on the Sacramento River near Glenn, California
Bathymetric and topographic surveys of the Upper Colorado River, May 13, 2021, to July 26, 2023
Multispectral images and field measurements of water depth from the Sacramento River near Glenn, California, acquired September 14-16, 2021
Digital orthophotos and field measurements of flow velocity from the Tanana and Nenana Rivers, Alaska, from August 2021
Topographic LiDAR surveys of rivers in Alaska, July 24-26, 2019
Digital elevation models (DEMs) and field measurements of flow velocity used to develop and test a multidimensional hydrodynamic model for a reach of the upper Sacramento River in northern California
Remotely sensed data and field measurements for mapping visible dye concentrations during a tracer experiment on the Missouri River near Columbia, MO, May 5, 2021
Remotely sensed data and field measurements of water depth and percent cover of benthic algae from two reaches of the Buffalo National River in Arkansas acquired in August 2021
Evaluating the potential for efficient, UAS-based reach-scale mapping of river channel bathymetry from multispectral images
A Robot Operating System (ROS) package for mapping flow fields in rivers via Particle Image Velocimetry (PIV)
A framework to facilitate development and testing of image-based river velocimetry algorithms
Performance evaluation of a channel rehabilitation project on the Lower Missouri River and implications for the dispersal of larval pallid sturgeon
The Toolbox for River Velocimetry using Images from Aircraft (TRiVIA)
Moving Aircraft River Velocimetry (MARV): Framework and proof-of-concept on the Tanana River
Evaluating the sensitivity of multi-dimensional model predictions of salmon habitat to the source of remotely sensed river bathymetry
Bathymetry retrieval from CubeSat image sequences with short time lags
River bathymetry retrieval from Landsat-9 images based on neural networks and comparison to SuperDove and Sentinel-2
Spectral mixture analysis for surveillance of harmful algal blooms (SMASH): A field-, laboratory-, and satellite-based approach to identifying cyanobacteria genera from remotely sensed data
Remote sensing of visible dye concentrations during a tracer experiment on a large, turbid river
Mapping benthic algae and cyanobacteria in river channels from aerial photographs and satellite images: A proof-of-concept investigation on the Buffalo National River, AR, USA
SAS: Software Application for SMASH (Spectral Mixture Analysis for Surveillance of Harmful Algal Blooms)
Toolbox for River Velocimetry using Images from Aircraft (TRiVIA)
ORByT - Optical River Bathymetry Toolkit
Science and Products
- Data
Filter Total Items: 43
Site visit cross section surveys and multispectral image data from gaging stations throughout the Willamette and Delaware River Basins from 2022 and code for Bathymetric Mapping using Gage Records and Image Databases (BaMGRID)
This data release includes cross section survey data collected during site visits to USGS gaging stations located throughout the Willamette and Delaware River Basins and multispectral images of these locations acquired as close in time as possible to the date of each site visit. In addition, MATLAB source code developed for the Bathymetric Mapping using Gage Records and Image Databases (BaMGRID) fHelicopter-based videos and orthomosaic maps produced for Integrated Water Science basin riverine study sites, 2022
A Bell 407 helicopter with a gyro-stabilized gimbal was used to collect aerial videos of Integrated Water Science basin riverine study sites in 2022. Videos were collected using both natural color and thermal infrared cameras. These videos were used to determine the feasibility of estimating river surface velocity using aerial imagery. Orthomosaic maps were produced from the natural color videos uVideo acquired from an Uncrewed Aerial System, UAS, and hydroacoustic measurements of flow velocity obtained along the North Santiam River, Oregon, in July 2022
A reach of the North Santiam River, Oregon, was used as a case study in an ongoing effort to develop and test image velocimetry algorithms for estimating surface flow velocities in river channels from remotely sensed data. Video was acquired from an unoccupied aircraft system, UAS, and used as input to the image velocimetry algorithms. Direct measurements of flow velocity were obtained using an acRemotely sensed data from a reach of the Sacramento River near Glenn, California, used to perform Particle Image Velocimetry (PIV) within the Robot Operating System (ROS)
This data release provides an example data set to accompany the manuscript titled "A Robot Operating System (ROS) package for mapping flow fields in rivers via Particle Image Velocimetry (PIV)", submitted to the journal Software X. This ROS *.bag file contains remotely sensed data acquired during an Uncrewed Aircraft System (UAS) flight along a reach of the Sacramento River near Glenn, California,Hydrodynamic model output and image simulation code for evaluating image-based river velocimetry from a case study on the Sacramento River near Glenn, California
This data release includes the data and code used for the paper titled "A framework to facilitate development and testing of image-based river velocimetry algorithms", published in the journal Earth Surface Processes and Landforms. Three *.csv files and five *.m files with MATLAB source code are included below. Each *.csv file contains output from a hydrodynamic model of a reach of the SacramentoBathymetric and topographic surveys of the Upper Colorado River, May 13, 2021, to July 26, 2023
Bathymetric and topographic surveys were collected along an approximately 47-kilometer reach of the Colorado River beginning at the Pumphouse Recreation site and extending downstream to the USGS streamgage located near the Colorado River Road (Catamount) bridge. The surveys were collected using real-time kinematic Global Navigation Satellite System (GNSS) receivers by USGS personnel during severalMultispectral images and field measurements of water depth from the Sacramento River near Glenn, California, acquired September 14-16, 2021
This data release includes multispectral images and field measurements of water depth from the Sacramento River near Glenn, California, used to evaluate the potential for efficient reach-scale mapping of river bathymetry using Uncrewed Aircraft Systems (UAS). The images were acquired by a MicaSense RedEdge-MX Dual Camera deployed from a Trinity F90 vertical take-off and landing (VTOL) UAS. The 4 kDigital orthophotos and field measurements of flow velocity from the Tanana and Nenana Rivers, Alaska, from August 2021
This data release includes digital orthophotos acquired from a fixed-wing aircraft and field measurements of flow velocity from the Tanana and Nenana Rivers near Nenana, Alaska, obtained on August 18 and 19, 2021. This parent data release includes links to child pages for two data sets produced during the study: 1. Acoustic Doppler Current Profiler (ADCP) field measurements of flow velocity fromTopographic LiDAR surveys of rivers in Alaska, July 24-26, 2019
The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of four rivers in Alaska from July 24-26, 2019 to support research related to remote sensing of river discharge. Data were acquired for the Matanuska, Chena, Salcha, and Tanana Rivers using a Riegl VQ-580 LiDAR. The LiDAR wasDigital elevation models (DEMs) and field measurements of flow velocity used to develop and test a multidimensional hydrodynamic model for a reach of the upper Sacramento River in northern California
This data release includes the input topographic data sets, model parameters, and validation field measurements of flow velocity used to develop and test multidimensional hydraulic models for a reach of the upper Sacramento River in northern California. Digital elevation models (DEMs) were developed by combining water depth maps of the reach, created using spectrally-based remote sensing methods,Remotely sensed data and field measurements for mapping visible dye concentrations during a tracer experiment on the Missouri River near Columbia, MO, May 5, 2021
This data release includes field spectra, UAS-based RGB videos, and digital orthophotography acquired from a manned fixed-wing aircraft, as well as in situ measurements of turbidity and Rhodamine WT dye concentration acquired during a tracer experiment performed on the Missouri River near Columbia, Missouri, on May 5, 2021. One of the primary goals of this tracer experiment was to assess the feasRemotely sensed data and field measurements of water depth and percent cover of benthic algae from two reaches of the Buffalo National River in Arkansas acquired in August 2021
This data release includes field measurements and remotely sensed data from two reaches of the Buffalo National River in northern Arkansas acquired in August and September of 2021 to support research on remote sensing of benthic algae from aerial photographs and satellite images. This landing page has links to child items where each type of data can be accessed: Field measurements of water depth - Publications
Filter Total Items: 42
Evaluating the potential for efficient, UAS-based reach-scale mapping of river channel bathymetry from multispectral images
Introduction: Information on spatial patterns of water depth in river channels is valuable for numerous applications, but such data can be difficult to obtain via traditional field methods. Ongoing developments in remote sensing technology have enabled various image-based approaches for mapping river bathymetry; this study evaluated the potential to retrieve depth from multispectral images acquireAuthorsCarl J. Legleiter, Lee R. HarrisonA Robot Operating System (ROS) package for mapping flow fields in rivers via Particle Image Velocimetry (PIV)
Non-contact, remote sensing approaches to measuring flow velocities in river channels are widely used, but typical workflows involve acquiring images in the field and then processing data later in the office. To reduce latency between acquisition and output, with the ultimate goal of enabling real-time image velocimetry, we developed a Robot Operating System (ROS) package for Particle Image VelociAuthorsCarl J. Legleiter, Michael DilleA framework to facilitate development and testing of image-based river velocimetry algorithms
Image-based methods have compelling, demonstrated potential for characterizing flow fields in rivers, but algorithms like particle image velocimetry (PIV) must be further tested and improved to enable more effective use of these techniques. This paper presents a framework designed for this exact purpose: Simulating Hydraulics and Images for Velocimetry Evaluation and Refinement (SHIVER). The approAuthorsCarl J. Legleiter, Paul J. KinzelPerformance evaluation of a channel rehabilitation project on the Lower Missouri River and implications for the dispersal of larval pallid sturgeon
In the Lower Missouri River, extensive channel modifications have altered hydraulic and morphologic conditions and reduced the river's ecological integrity. One species that has been adversely affected by these changes is the pallid sturgeon (Scaphirhynchus albus). Mainstem dams on the Missouri River restrict the upstream migration of adults and limit the downstream dispersal of larvae. ChannelizaAuthorsBrandon James Sansom, Bruce Call, Carl J. Legleiter, R. B. JacobsonThe Toolbox for River Velocimetry using Images from Aircraft (TRiVIA)
Accurate knowledge of the speed at which water moves along a river is essential for understanding ecohydraulic processes and managing natural resources. Measuring flow velocity via remote sensing can be more efficient than conventional field methods, and powerful computational techniques for inferring velocity fields from videos or image time series have been developed. The development of dedicateAuthorsCarl J. Legleiter, Paul J. KinzelMoving Aircraft River Velocimetry (MARV): Framework and proof-of-concept on the Tanana River
Information on velocity fields in rivers is critical for designing infrastructure, modeling contaminant transport, and assessing habitat. Although non-contact approaches to measuring flow velocity are well established, these methods assume a stationary imaging platform. This study eliminates this constraint by introducing a framework for moving aircraft river velocimetry (MARV). The workflow takesAuthorsCarl J. Legleiter, Paul J. Kinzel, Mark Laker, Jeff ConawayEvaluating the sensitivity of multi-dimensional model predictions of salmon habitat to the source of remotely sensed river bathymetry
Multi-dimensional numerical models are fundamental tools for investigating biophysical processes in aquatic ecosystems. Remote sensing techniques increase the feasibility of applying such models at riverscape scales, but tests of model performance on large rivers have been limited. We evaluated the potential to develop two-dimensional (2D) and three-dimensional (3D) hydrodynamic models for a 1.6-kAuthorsLee R. Harrison, Carl J. Legleiter, Vamsi K Sridharana, Peter Dudley, Miles E. DanielsBathymetry retrieval from CubeSat image sequences with short time lags
The rapid expansion of CubeSat constellations could revolutionize the way inland and nearshore coastal waters are monitored from space. This potential stems from the ability of CubeSats to provide daily imagery with global coverage at meter-scale spatial resolution. In this study, we explore the unique opportunity to improve the retrieval of bathymetry offered by CubeSats, specifically those of thAuthorsMilad Niroumand-Jadidi, Carl J. Legleiter, Francesca BovoloRiver bathymetry retrieval from Landsat-9 images based on neural networks and comparison to SuperDove and Sentinel-2
The Landsat mission has kept an eye on our planet, including water bodies, for 50 years. With the launch of Landsat-9 and its onboard Operational Land Imager 2 (OLI-2) in September 2021, more subtle variations in brightness (14-bit dynamic range) can be captured than previous sensors in the Landsat series (e.g., 12-bit Landsat-8). The enhanced radiometric resolution of OLI-2 appeals to the aquaticAuthorsMilad Niroumand-Jadidi, Carl J. Legleiter, Francesca BovoloSpectral mixture analysis for surveillance of harmful algal blooms (SMASH): A field-, laboratory-, and satellite-based approach to identifying cyanobacteria genera from remotely sensed data
Algal blooms around the world are increasing in frequency and severity, often with the possibility of adverse effects on human and ecosystem health. The health and economic impacts associated with harmful algal blooms, or HABs, provide compelling rationale for developing new methods for monitoring these events via remote sensing. Although concentrations of chlorophyll-a and key pigments like phycoAuthorsCarl J. Legleiter, Tyler Victor King, Kurt D. Carpenter, Natalie Celeste Hall, Adam Mumford, E. Terrence Slonecker, Jennifer L. Graham, Victoria G. Stengel, Nancy Simon, Barry H. RosenRemote sensing of visible dye concentrations during a tracer experiment on a large, turbid river
Understanding dispersion in rivers is critical for numerous applications, such as characterizing larval drift for endangered fish species and responding to spills of hazardous materials. Injecting a visible dye into the river can yield insight on dispersion processes, but conventional field instrumentation yields limited data on variations in dye concentration over time at a few, fixed points. RemAuthorsCarl J. Legleiter, Brandon James Sansom, R. B. JacobsonMapping benthic algae and cyanobacteria in river channels from aerial photographs and satellite images: A proof-of-concept investigation on the Buffalo National River, AR, USA
Although rivers are of immense practical, aesthetic, and recreational value, these aquatic habitats are particularly sensitive to environmental changes. Increasingly, changes in streamflow and water quality are resulting in blooms of bottom-attached (benthic) algae, also known as periphyton, which have become widespread in many water bodies of US national parks. Because these blooms degrade visitoAuthorsCarl J. Legleiter, Shawn W Hodges - Software
SAS: Software Application for SMASH (Spectral Mixture Analysis for Surveillance of Harmful Algal Blooms)
The Software Application for SMASH (Spectral Mixture Analysis for Surveillance of Harmful Algal Blooms), or SAS for short, is an application to facilitate mapping of potentially harmful algal blooms in reservoirs, rivers, and lakes from remotely sensed data. More specifically, SAS is designed to exploit the detailed observations of reflectance available within a hyperspectral image to infer whichToolbox for River Velocimetry using Images from Aircraft (TRiVIA)
# TRiVIA Toolbox for River Velocimetry using Images from Aircraft: TRiVIA ## Description The Toolbox for River Velocimetry using Images from Aircraft, or TRiVIA for short, is an application to facilitate estimation of surface flow velocities in river channels from various types of remotely sensed data acquired with a nadir-viewing geometry (i.e., looking straight down). Spatially distributed infoORByT - Optical River Bathymetry Toolkit
The Optical River Bathymetry Toolkit, ORByT, is an application to facilitate mapping water depth in river channels from passive optical image data. ORByT provides an integrated workflow for image processing, depth retrieval, and export of results.