20 Sep 2021

Integration of Autonomous Electric Transport Vehicles into a Tactical Microgrid: Final Report

Abstract: The objective of the Autonomous Transport Innovation (ATI) technical research program is to investigate current gaps and challenges and develop solutions to integrate emerging electric transport vehicles, vehicle autonomy, vehicle-to-grid (V2G) charging and microgrid technologies with military legacy equipment. The ATI research area objectives are to: identify unique military requirements for autonomous transportation technologies; identify currently available technologies that can be adopted for military applications and validate the suitability of these technologies to close need gaps; identify research and operational tests for autonomous transport vehicles; investigate requirements for testing and demonstrating of bidirectional-vehicle charging within a tactical environment; develop requirements for a sensored, living laboratory that will be used to assess the performance of autonomous innovations; and integrate open standards to promote interoperability and broad-platform compatibility. This final report summarizes the team’s research, which resulted in an approach to develop a sensored, living laboratory with operational testing capability to assess the safety, utility, interoperability, and resiliency of autonomous electric transport and V2G technologies in a tactical microgrid. The living laboratory will support research and assessment of emerging technologies and determine the prospect for implementation in defense transport operations and contingency base energy resilience.

20 Sep 2021

Autonomous Navigation and Mapping in a Simulated Environment

Abstract: Unknown Environment Exploration (UEE) with an Unmanned Ground Vehicle (UGV) is extremely challenging. This report investigates a frontier exploration approach, in simulation, that leverages Simultaneous Localization And Mapping (SLAM) to efficiently explore unknown areas by finding navigable routes. The solution utilizes a diverse sensor payload that includes wheel encoders, three-dimensional (3-D) LIDAR, and Red, Green, Blue and Depth (RGBD) cameras. The main goal of this effort is to leverage frontier-based exploration with a UGV to produce a 3-D map (up to 10 cm resolution). The solution provided leverages the Robot Operating System (ROS).

20 Sep 2021

A Multi-biome Study of Tree Cover Detection Using the Forest Cover Index

Abstract: Tree cover maps derived from satellite and aerial imagery directly support civil and military operations. However, distinguishing tree cover from other vegetative land covers is an analytical challenge. While the commonly used Normalized Difference Vegetation Index (NDVI) can identify vegetative cover, it does not consistently distinguish between tree and low-stature vegetation. The Forest Cover Index (FCI) algorithm was developed to take the multiplicative product of the red and near infrared bands and apply a threshold to separate tree cover from non-tree cover in multispectral imagery (MSI). Previous testing focused on one study site using 2-m resolution commercial MSI from WorldView-2 and 30-m resolution imagery from Landsat-7. New testing in this work used 3-m imagery from PlanetScope and 10-m imagery from Sentinel-2 in imagery in sites across 12 biomes in South and Central America and North Korea. Overall accuracy ranged between 23% and 97% for Sentinel-2 imagery and between 51% and 98% for PlanetScope imagery. Future research will focus on automating the identification of the threshold that separates tree from other land covers, exploring use of the output for machine learning applications, and incorporating ancillary data such as digital surface models and existing tree cover maps.

20 Sep 2021

Performance Testing and Modeling of a Transpired Ventilation Preheat Solar Wall: Performance Evaluation of Facilities at Fort Drum, NY, and Kansas Air National Guard, Topeka, KS

Abstract: This work performed measurement and verification of installed, operational solar wall systems at Fort Drum, NY, and Forbes Field, Air National Guard, Topeka, KS. Actual annual savings were compared estimated savings generated by a solar wall modeling tool (RETScreen). A comparison with the RETScreen modeling tool shows that the measured actively heated air provided by the solar wall provides 57% more heat than the RETScreen tool predicted, after accounting for boiler efficiency. The solar wall at Fort Drum yields a net savings of $851/yr, for a simple payback of 146 years and a SIR of 0.16. RETScreen models indicate that the solar wall system at Forbes Field, Kansas Air National Guard, Topeka, KS saves $9,350/yr, for a simple payback of 58.8 years and a SIR of 0.34. Although results showed that, due to low natural gas prices, the Fort Drum system was not economically viable, it was recommended that the system still be used to meet renewable energy and fossil fuel reduction goals. The current system becomes economical (SIR 1.00) at a natural gas rate of $16.00/MMBTU or $1.60 /therm.

17 Sep 2021

Morphodynamics of Barrier-Inlet Systems in the Context of Regional Sediment Management, with Case Studies from West-Central Florida, USA

Abstract: The temporal and spatial scales controlling the morphodynamics of barrier-inlet systems are critical components of regional sediment management practice. This paper discusses regional sediment management methods employed at multiple barrier-inlet systems, with case studies from West-Central Florida. A decision-support tool is proposed for regional sediment management with discussion of its application to barrier-inlet systems. Connecting multiple barrier islands and inlets at appropriate spatio-temporal scales is critical in developing an appropriately scoped sediment management plan for a barrier-inlet system. Evaluating sediment bypassing capacity and overall inlet morphodynamics can better inform regional sand sharing along barrier-inlet coastlines; particularly where sediment resources are scarce and a close coupling between inlet dredging and beach placement is vital to long-term sustainable management. Continued sea-level rise and anthropogenic activities may intensify the need for investigating longer-term processes and expanding regional planning at a centennial timescale and are acknowledged as challenging tasks for RSM studies. Specifically, we suggested that a regionally focused, multi-inlet study was necessary for management plan of individual inlet for the west-central Florida case studies. Key recommendations based on the case studies are included.

17 Sep 2021

Evaluation of light limitation and depth on germinated seeds of two species of water chestnut cultured under experimental conditions

Abstract: This technical note describes the results of a mesocosm experiment to determine the light and depth limitations of growth chamber germinated seeds of two species of water chestnut (Trapa spp.) naturalized in the northeastern United States.

17 Sep 2021

Associated Words Explorer (AWE) User Manual

Abstract: This manual is intended for new users with minimal or no experience with using the Associated Word Explorer (AWE) tool. The goal of this document is to give an overview of the main functions of AWE. The primary focus of this document is to demonstrate functionality. Every effort has been made to ensure this document is an accurate representation of the functionality of the AWE tool. For additional information about this manual, contact ERDC.JAIC@erdc.dren.mil

16 Sep 2021

An Investigation of the Feasibility of Assimilating COSMOS Soil Moisture into GeoWATCH

Abstract: This project objective evaluated the potential of improving linked weather-and-mobility model predictions by blending soil moisture observations from a Cosmic-ray Soil Moisture Observing System (COSMOS) sensor with weather-informed predictions of soil moisture and soil strength from the Geospatial Weather-Affected Terrain Conditions and Hazards (GeoWATCH). Assimilating vehicle-borne COSMOS observations that measure local effects model predictions of soil moisture offered potential to produce more accurate soil strength and vehicle mobility forecast was the hypothesis. This project compared soil moisture observations from a COSMOS mobile sensor driven around an area near Iowa Falls, IA, with both GeoWATCH soil moisture predictions and in situ probe observations. The evaluation of the COSMOS rover data finds that the soil moisture measurements contain a low measurement bias while the GeoWATCH estimates more closely matched the in situ data. The COSMOS rover captured a larger dynamic range of soil moisture conditions as compared to GeoWATCH, capturing both very wet and very dry soil conditions, which may better flag areas of high risk for mobility considerations. Overall, more study of the COSMOS rover is needed to better understand sensor performance in a variety of soil conditions to determine the feasibility of assimilating the COSMOS rover estimates into GeoWATCH.

16 Sep 2021

Penetration Modeling of Ultra‐High Performance Concrete using Multiscale Meshfree Methods

Abstract: Terminal ballistics of concrete is of extreme importance to the military and civil communities. Over the past few decades, ultra‐high performance concrete (UHPC) has been developed for various applications in the design of protective structures because UHPC has an enhanced ballistic resistance over conventional strength concrete. Developing predictive numerical models of UHPC subjected to penetration is critical in understanding the material's enhanced performance. This study employs the advanced fundamental concrete (AFC) model, and it runs inside the reproducing kernel particle method (RKPM)‐based code known as the nonlinear meshfree analysis program (NMAP). NMAP is advantageous for modeling impact and penetration problems that exhibit extreme deformation and material fragmentation. A comprehensive experimental study was conducted to characterize the UHPC. The investigation consisted of fracture toughness testing, the utilization of nondestructive microcomputed tomography analysis, and projectile penetration shots on the UHPC targets. To improve the accuracy of the model, a new scaled damage evolution law (SDEL) is employed within the microcrack informed damage model. During the homogenized macroscopic calculation, the corresponding microscopic cell needs to be dimensionally equivalent to the mesh dimension when the partial differential equation becomes ill posed and strain softening ensues. Results of numerical investigations will be compared with results of penetration experiments.

16 Sep 2021

Natural Language Indexing for Pedoinformatics

Abstract: The multiple schema for the classification of soils rely on differing criteria but the major soil science systems, including the United States Department of Agriculture (USDA) and the international harmonized World Reference Base for Soil Resources soil classification systems, are primarily based on inferred pedogenesis. Largely these classifications are compiled from individual observations of soil characteristics within soil profiles, and the vast majority of this pedologic information is contained in non-quantitative text descriptions. We present initial text mining analyses of parsed text in the digitally available USDA soil taxonomy documentation and the Soil Survey Geographic database. Previous research has shown that latent information structure can be extracted from scientific literature using Natural Language Processing techniques, and we show that this latent information can be used to expedite query performance by using syntactic elements and part-of-speech tags as indices. Technical vocabulary often poses a text mining challenge due to the rarity of its diction in the broader context. We introduce an extension to the common English vocabulary that allows for nearly-complete indexing of USDA Soil Series Descriptions.