Very Shallow Water Bathymetry Retrieval from Hyperspectral Imagery at the Virginia Coast Reserve (VCR\u2707) Multi-Sensor Campaign

A number of institutions, including the Naval Research Laboratory (NRL), have developed look up tables for remote retrieval of bathymetry and in-water optical properties from hyperspectral imagery (HSI) [6]. For bathymetry retrieval, the lower limit is the very shallow water case (here defined as \u3c 2m), a depth zone which is not well resolved by many existing bathymetric LIDAR sensors, such as SHOALS [4]. The ability to rapidly model these shallow water depths from HSI directly has potential benefits for combined HSI/LIDAR systems such as the Compact Hydrographic Airborne Rapid Total Survey (CHARTS) [10]. In this study, we focused on the validation of a near infra-red feature, corresponding to a local minimum in absorption (and therefore a local peak in reflectance), which can be correlated directly to bathymetry with a high degree of confidence. Compared to other VNIR wavelengths, this particular near-IR feature corresponds to a peak in the correlation with depth in this very shallow water regime, and this is a spectral range where reflectance depends primarily on water depth (water absorption) and bottom type, with suspended constituents playing a secondary role

No room to roam: King Cobras reduce movement in agriculture

Background Studying animal movement provides insights into how animals react to land-use changes. As agriculture expands, we can use animal movement to examine how animals change their behaviour in response. Recent reviews show a tendency for mammalian species to reduce movements in response to increased human landscape modification, but reptile movements have not been as extensively studied. Methods We examined movements of a large reptilian predator, the King Cobra (Ophiophagus hannah), in Northeast Thailand. We used a consistent regime of radio telemetry tracking to document movements across protected forest and adjacent agricultural areas. Using dynamic Brownian Bridge Movement Model derived motion variance, Integrated Step-Selection Functions, and metrics of site reuse, we examined how King Cobra movements changed in agricultural areas. Results Motion variance values indicated that King Cobra movements increased in forested areas and tended to decrease in agricultural areas. Our Integrated Step-Selection Functions revealed that when moving in agricultural areas King Cobras restricted their movements to remain within vegetated semi-natural areas, often located along the banks of irrigation canals. Site reuse metrics of residency time and number of revisits appeared unaffected by distance to landscape features (forests, semi-natural areas, settlements, water bodies, and roads). Neither motion variance nor reuse metrics were consistently affected by the presence of threatening landscape features (e.g. roads, human settlements), suggesting that King Cobras will remain in close proximity to threats, provided habitat patches are available. Conclusions Although King Cobras displayed individual heterogeneity in their response to agricultural landscapes, the overall trend suggested reduced movements when faced with fragmented habitat patches embedded in an otherwise inhospitable land-use matrix. Movement reductions are consistent with findings for mammals and forest specialist species.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Exploration of the Colorado River of the West and its tributaries : explored in 1869, 1870, 1871, and 1872, under the direction of the Secretary of the Smithsonian Institution /

Map and profile in pocket. Chapters 1-9 of pt. 1, with six chapters added, were pub. later (Meadville, Pa., 1895) under title: Canyons of the Colorado, by J.W. Powell ... pt. 1. History of the explorations of the cañons of the Colorado [May 24-Sept. 20, 1869] Report on a trip to the mouth of the Dirty Devil River [May 27-July 11, 1872] by A.H. Thompson.--pt. 2. On the physical features of the valley of the Colorado.--pt. 3. Zoology: Abstracts of results of a study of the genera Geomys and Thomomys, by Elliott Coues. Addendum A. The cranial and dental characters of Geomydæ, by Elliott Coues. Addendum B. Notes on the salamander of Florida (Geomys Tueza) by G.B. Goode. The present report does not include a narrative of the second descent of the river in 1871-1872, a detailed account of which may be found in F.S. Dellenbaugh's A canyon voyage, New York, 1908.Includes index.The present report does not include a narrative of the second descent of the river in 1871-1872, a detailed account of which may be found in F.S. Dellenbaugh's A canyon voyage, New York, 1908.Map and profile in pocket.pt. 1. History of the explorations of the cañons of the Colorado [May 24-Sept. 20, 1869]. Report on a trip to the mouth of the Dirty Devil River [May 27-July 11, 1872] / by A.H. Thompson -- pt. 2. On the physical features of the valley of the Colorado -- pt. 3. Zoology: Abstracts of results of a study of the genera Geomys and Thomomys / by Elliott Coues. Addendum A. The cranial and dental characters of Geomyidae. Addendum B. Notes on the "salamander" of Florida (Geomys Tueza) / by G. Brown Goode.J.W. Powell in charge.Map and profile in pocket. Chapters 1-9 of pt. 1, with six chapters added, were pub. later (Meadville, Pa., 1895) under title: Canyons of the Colorado, by J.W. Powell ... pt. 1. History of the explorations of the cañons of the Colorado [May 24-Sept. 20, 1869] Report on a trip to the mouth of the Dirty Devil River [May 27-July 11, 1872] by A.H. Thompson.--pt. 2. On the physical features of the valley of the Colorado.--pt. 3. Zoology: Abstracts of results of a study of the genera Geomys and Thomomys, by Elliott Coues. Addendum A. The cranial and dental characters of Geomydæ, by Elliott Coues. Addendum B. Notes on the salamander of Florida (Geomys Tueza) by G.B. Goode. The present report does not include a narrative of the second descent of the river in 1871-1872, a detailed account of which may be found in F.S. Dellenbaugh's A canyon voyage, New York, 1908.Mode of access: Internet.Blue cloth

Bathymetry Retrieval from Hyperspectral Imagery in the Very Shallow Water Limit: a Case Study from the 2007 Virginia Coast Reserve (VCR\u2707) Multi-Sensor Campaign

We focus on the validation of a simplified approach to bathymetry retrieval from hyperspectral imagery (HSI) in the very shallow water limit (less than 1–2 m), where many existing bathymetric LIDAR sensors perform poorly. In this depth regime, near infra-red (NIR) reflectance depends primarily on water depth (water absorption) and bottom type, with suspended constituents playing a secondary role. Our processing framework exploits two optimal regions where a simple model depending on bottom type and water depth can be applied in the very shallow limit. These two optimal spectral regions are at a local maximum in the near infra-red reflectance near 810 nm, corresponding to a local minimum in absorption, and a maximum in the first derivative of the reflectance near 720 nm. These two regions correspond to peaks in spectral correlation with bathymetry at these depths