Assessment of ocean prediction model for Naval Operations using acoustic preset

OCEANS2005, MTS/IEEE Conference Proceedings, DVD-ROMThe outcome of a battlefield engagement is often determined by the advantages and disadvantages held by each adversary. On the modern battlefield, the possessor of the best technology often has the upper hand, but only if that advanced technology is used properly and efficiently. In order to exploit this advantage and optimize the effectiveness of high technology sensor and weapon systems, it is essential to understand the impact on them by the environment. In the arena of Anti-Submarine Warfare (ASW), the ocean environment determines the performance of the acoustic sensors employed and the success of any associated weapon systems. Since acoustic sensors detect underwater sound waves, understanding how those waves propagate is crucial to knowing how the sensors will perform and being able to optimize their performance in a given situation. To gain this understanding, an accurate depiction of the ocean environment is necessary. How acoustic waves propagate from one location to another under water is determined by many factors, some of which are described by the sound speed profile (SSP). If the environmental properties of temperature and salinity are known over the entire depth range, the SSP can be compiled by using them in an empirical formula to calculate the expected sound speed in a vertical column of water. One way to determine these environmental properties is to measure them in situ, such as by conductivity-temperature-depth or expendable bathythermograph (XBT) casts. This method is not always tactically feasible and only gives the vertical profile at one location producing a very limited picture of the regional ocean structure. Another method is to estimate the ocean conditions using numerical models. The valued-aided ocean prediction models to ASW is assessed in this study. Such quantitative analyses offer a means to optimize the ASW requirements and technical capabilities of new weapon systems. We use observed and modeled 3-D fields of temperature, salinity, and sound speed. Compare model profiles to observed profiles. Do ocean models predict the vertical features of the observational data? Run representative modeled and observed SSP profiles through Navy’s acoustic models to see if there is an acoustic difference in propagation and weapon preset

The multidimensionality of the niche reveals functional diversity changes in benthic marine biotas across geological time

Abstract Despite growing attention on the influence of functional diversity changes on ecosystem functioning, a palaeoecological perspective on the long-term dynamic of functional diversity, including mass extinction crises, is still lacking. Here, using a novel multidimensional functional framework and comprehensive null-models, we compare the functional structure of Cambrian, Silurian and modern benthic marine biotas. We demonstrate that, after controlling for increases in taxonomic diversity, functional richness increased incrementally between each time interval with benthic taxa filling progressively more functional space, combined with a significant functional dissimilarity between periods. The modern benthic biota functionally overlaps with fossil biotas but some modern taxa, especially large predators, have new trait combinations that may allow more functions to be performed. From a methodological perspective, these results illustrate the benefits of using multidimensional instead of lower dimensional functional frameworks when studying changes in functional diversity over space and time

Pennsylvania Folklife Vol. 34, No. 4

• Coverlets • Sign Painting • Reverse Painting on Glass • Kites • Snake Lore • Horncraft • Weathervanes and Country Signs • Festival Focus • Sheep Shearing & Natural Knits • Bread Baking Among the Pennsylvania Dutch • The Craft of Rushing • Toy Soldier Casting • Pennsylvania Dutch Humor • Fireside Brooms and Whirligigs • Springerlehttps://digitalcommons.ursinus.edu/pafolklifemag/1108/thumbnail.jp

Rise of the Earliest Tetrapods: An Early Devonian Origin from Marine Environment

Tetrapod fossil tracks are known from the Middle Devonian (Eifelian at ca. 397 million years ago - MYA), and their earliest bony remains from the Upper Devonian (Frasnian at 375–385 MYA). Tetrapods are now generally considered to have colonized land during the Carboniferous (i.e., after 359 MYA), which is considered to be one of the major events in the history of life. Our analysis on tetrapod evolution was performed using molecular data consisting of 13 proteins from 17 species and different paleontological data. The analysis on the molecular data was performed with the program TreeSAAP and the results were analyzed to see if they had implications on the paleontological data collected. The results have shown that tetrapods evolved from marine environments during times of higher oxygen levels. The change in environmental conditions played a major role in their evolution. According to our analysis this evolution occurred at about 397–416 MYA during the Early Devonian unlike previously thought. This idea is supported by various environmental factors such as sea levels and oxygen rate, and biotic factors such as biodiversity of arthropods and coral reefs. The molecular data also strongly supports lungfish as tetrapod's closest living relative

Impact of GFO satellite on naval antisubmarine warfare

NATO RTB-SPSM01 Specialists Meeting on "Emerging and Future Technologies for Space Based Operations Support to NATO Military Operations", DVD-ROMThe purpose of this study is to assess the benefit of assimilating satellite altimeter data especially the US Navy’s GFO into the Modular Ocean Data Assimilation System (MODAS). To accomplish this, two different MODAS fields are used by the Weapon Acoustic Preset Program (WAPP) to determine suggested presets for a Mk 48 variant torpedo. The MODAS fields differ in that one uses altimeter data assimilated from three satellites while the other uses no altimeter data. The metric used to compare the two sets of outputs is the relative difference in acoustic coverage area generated by WAPP. Output presets are created for five different scenarios, two Anti-Surface Warfare scenarios and three Anti-Submarine Warfare scenarios, in each of three regions: the East China Sea, Sea of Japan, and an area south of Japan that includes the Kuroshio current. Analysis of the output reveals that, in some situations, WAPP output is very sensitive to the inclusion of the altimeter data because of the resulting differences in the subsurface predictions. The change in weapon presets could be so much that the effectiveness of the weapon might be affected

Satellite Data Assimilation for Naval Undersea Capability Improvement

OCEANS 2003, MTS/IEEE Conference Proceedings, DVD-RO

Ocean nowcast/forecast systems for improvement of Naval undersea capabilities

Marine Technology Society Journal, 41 (2), Summer 2007The U.S. Navy is a major investor in ocean model development. The pay-off of such an investment is the value-added ocean nowcast/forecast systems on naval operations and warfare effectiveness. The purpose of this paper is to investigate the value added of the Navy’s nowcast/forecast system to naval antisubmarine warfare (ASW) and anti-surface warfare (ASUW). The nowcast/forecast versus observational fields were used by the Weapon Acoustic Preset Program (WAPP) to determine the suggested presets for Mk 48 variant torpedo. The metric used to compare the two sets of outputs is the relative difference in acoustic coverage area generated by WAPP. Output presets are created for five different scenarios, two ASUW scenarios and three ASW scenarios in the South China Sea. The same metrics used in the nowcast/forecast case were used to generate and compare the acoustic coverage. Analysis of the output reveals that the ocean forecast system outperformed the nowcast system in most scenarios

The Radio Number of Biregular Paths

A radio labeling of a graph is function f:V(G)->{0,1,...,l} such that |f(u)-f(v)|>= diam(G)+1+d_G(u,v) for all u and v in V(G). The radio number of a graph G, denoted as rn(G), is the minimum span of any radio labeling of G. We provide background on some graphs with known radio numbers. We define a class of trees called biregularized paths which are formed by taking a path P and adding leaves to the vertices of P until each has the same degree m. We give bounds for the radio numbers of both the even and odd biregularized paths and give algorithms that attain each of these bounds respectively. We then discuss extending our results to a more general class of trees

Satellite data assimilation for improvement of Naval undersea capability

Marine Technology Society Journal, 38 (1), 11-23.Impact of satellite data assimilation on naval undersea capability is investigated using ocean hydrographic products without and with satellite data assimilation. The former is the Navy’s Global Digital Environmental Model (GDEM), providing a monthly mean; the latter is the Modular Ocean Data Assimilation System (MODAS) providing synoptic analyses based upon satellite data. The two environmental datasets are taken as the input into the Weapon Acoustic Preset Program to determine the suggested presets for an Mk 48 torpedo. The acoustic coverage area generated by the program will be used as the metric to compare the two sets of outputs. The output presets were created for two different scenarios, an anti-surface warfare (ASUW) and an anti-submarine warfare (ASW); and three different depth bands, shallow, mid, and deep. After analyzing the output, it became clear that there was a great difference in the presets for the shallow depth band, and that as depth increased, the difference between the presets decreased. Therefore, the MODAS product, and in turn the satellite data assimilation, had greatest impact in the shallow depth band. The ASW presets also seemed to be slightly less sensitive to differences than did presets in the ASUW scenario