D -- VALIDATE AND PARAMETERIZE TWO SHIP TARGETS UTILIZING RESULTS FROM RIGOROUS HYDRODYNAMIC WAKE MODELS

Notice Date

September 17, 2001

Contracting Office

Bid Office, SPAWARSYSCEN, Code D21B, 53570 Silvergate Avenue, Bldg. A33, Room 0061, San Diego, CA 92152-5112

ZIP Code

92152-5112

Solicitation Number

N66001-01-Q-3284

Response Due

September 23, 2001

Point of Contact

Purchasing Agent, Ms. Gina Bennett, 2212, (619) 553-5208. Contracting Officer, Ms. Sylvia Proffit, 2211, (619) 553-3292.

Description

This is a combined synopsis/solicitation prepared in accordance with FAR Part 13. No RFQ will be prepared or made available. The Government intends to award, on a Sole Source basis, an order to ThermoAnalytics, Inc. in accordance with the below statement of work. Validate and Parameterize Two Ship Targets using results from Rigorous Hydrodynamic Wake Models. Paragraph 1.0. BACKGROUND AND DESCRIPTION OF TASK. Paragraph 1.1. This task will improve the target thermal radiance calculations for moving ship targets in the Target Acquisition Weather Software (TAWS) and the Multi-Service Electro-optic Signature (MuSES) calculation software. TAWS is a strike warfare tactical decision aid developed by the Air Force Research Laboratory (AFRL). The purpose of TAWS is to predict the performance of airborne electrooptical weapons systems for a given set of targets, backgrounds and forecast weather conditions. TAWS calculates target-background contrasts to predict detection range, recognition range, lock-on range, optimum approach azimuth, best altitude, and thermal crossover times for a large variety of airborne sensors. MuSES is both a standalone target builder and thermal effects modeling product. The MuSES thermal processor module is part of TAWS and the standalone MuSES engineering package is used separately to build new targets as needed for TAWS. For more information on MuSES, see http://www.thermoanalytics.com/products/muses/index.html. Paragraph 1.2. The Navy is leveraging on this multimillion-dollar Air Force TAWS effort and steering future development to be more inline with the needs of the Navy and the marine environment. This task furthers this goal. Paragraph 1.3. The current thermal models of ship targets in MuSES and TAWS need a prediction of wake effects sufficiently accurate and comprehensive to correctly manifest the observable IR signature. An initial empirically based Wake Model was developed by ThermoAnalytics that provides some of the wake effects for use in TAWS. This task will provide a number of benchmarks with which the empirical model can be compared to the results of a computationally intensive, state-of-the-art computational fluid dynamics (CFD) wake prediction. During the comparison, any opportunity to bring the empirical model in closer agreement with the CFD results will be explored. In addition, the sensitivity of the IR signature to accuracy of the wake properties will be evaluated to assess the model accuracy versus performance requirements. Techniques such as enhancing current model features, adding other important omitted physical processes to the empirical model, and interpolating stored CFD results will be considered. Two types of ship targets are of interest, a displacement motion vessel, such as the Research Vessel Point Sur (or alternatively the DD963) and a hydroplaning motion vessel, the Boghammer. Any future ship targets added to MuSES or TAWS will be considered as separate future tasks depending on the results of this task and how much the wake properties differ from these two types of ships. Paragraph 1.4. The effects of the Kelvin wave field, bow wake, transom stern wake, and near-field turbulent wake and bubble fields are to be included in the rigorous CFD models. These hydrodynamic models will give a representation of the topography (i.e., facet tilt and direction coordinates) and speciation properties (e.g., foam content, emissive properties, physical temperature relative to sea surface temperature, etc.) for each facet in a multi-faceted grid describing the near-field wake area for the given ship type and speed. Paragraph 1.5. Criteria will be established to define the boundaries of the wake area to be modeled. Perhaps, one beam width on either side of the ship and one to three ship lengths behind the ship. Criteria also will be established to determine which near-field wake facet radiances will eventually be combined with the thermal radiance of the ship structure itself. For example, those facets with a significant variance, say three db, from the surrounding ocean background radiance or at least fifty percent foam content may be considered part of the target wake. Flexibility will be given to the developer to use whatever criteria and algorithms make sense in considering optimization between accuracy, runtimes, and costs. Paragraph 1.6. The deliverables from this task will provide: (1) subroutines/functions for TAWS that provide source radiance terms for determining detection ranges for these new ship-plus-wake targets, and (2) a MuSES software visualization that matches the state-of-the-art CFD models for the cases of low and high ship speeds. Paragraph 1.7. This task requires detailed knowledge of both MuSES and TAWS design and theory of operation. This task must coordinate with the overall TAWS program development, scheduling, and configuration management so that we will support the TAWS delivery schedule as set by the Air Force. Coordination, communication, and cooperative efforts with the TAWS developers and the hydrodynamics community are essential. ThermoAnalytics, Inc. is the sole developer of MuSES and a co-developer of TAWS. They are responsible for both the software development and maintenance of the overall MuSES product and similar for the TAWS product. They have many years of related experience working on these projects and similar Weather Impacted Decision Aids (WIDA). For these reasons this task will be sole-source because it is unlikely that any other source can meet these requirements. Paragraph 2.0. SCOPE. Paragraph 2.1. The developer will employ computationally intensive state-of-the-art hydrodynamic wake modeling to characterize the surface wake area at an appropriate grid space resolutions for two ships at two ship speeds. It is assumed the developer for this task will work closely with the hydrodynamics community, providing funding and input information, such as CAD wireframe diagrams of the ships, in return for the required CFD model runs and consultant time for the hydrodynamics part of the task. Paragraph 2.2. The two ships whose wake effects are to be modeled are the Research Vessel Point Sur or DD-963 as a displacement moving vessel, and a planning boat, the Boghammer, each at two speeds, as described below. Paragraph 2.3. Given the surface wake characteristics from the CFD models, the radiance of the significant wake area will then be determined based on emissive wake radiance and reflected atmospheric radiance as a function of view angle and wind speed and wind direction. It is assumed that the various emissivities of the whitewater bow spray, turbulent bubble fields, and slope areas can be estimated based on known foam and seawater properties and radiances calculated based on typical wake temperatures relative to a given sea surface temperature. It is assumed that this model will represent an average random sea condition, temperature profile and surfactant distribution. It is assumed that this task will not account for changes in ocean swell direction or wave spectra, salinity, subsurface temperature profiles, or surfactant concentrations for these are not currently available as inputs to TAWS. However, the developer should keep in mind that these may be available in future tasks. Paragraph 2.4. A library function (or functions) will be created for TAWS to make the radiance calculations and combine the total radiance of the significant wake area with the apparent ship radiance. This combined radiance will be suitable for TAWS in calculating target-plus-wake minus background contrast values for detection range predictions. Paragraph 2.5. The wake grid and thermal effects will also be incorporated into the standalone MuSES engineering package for visualization and validation purposes. Paragraph 3.0. TECHNICAL REQUIREMENTS. Paragraph 3.1. The contractor/developer shall research options and utilize the best high performance hydrodynamic models available for modeling wake effects. These shall include effects of the bow wake, transom stern wake, Kelvin wave field, and near-field turbulent stern wake. The developer shall purchase consultation as needed and purchase model runs for two ships at two ship speeds. The two ships (R/V Pt Sur or DD-963 and Boghammer) shall be modeled at high cruising speed and low maneuvering speed. The results of these CFD runs will be topographic descriptions of the wake area near the ship with sufficient facet information to calculate the thermal radiance properties for TAWS and MuSES. The developer will work with the hydrodynamics modelers to define appropriate wake boundary areas and grid spacing based on attainable accuracies, wake spread, and typical TAWS sensor fields-of-view. Paragraph 3.2. The developer shall research and determine methods or algorithms for estimating any unavailable parameters needed to determine thermal radiance. This may include variance of wake emissive properties or estimating typical wake temperatures relative to given sea surface temperatures. The developer shall also determine reasonable criteria for determining which wake facets should be considered target rather than ocean background. Only those wake facets that have a significant radiance contrast compared to the sea background and clutter variance should be added to the target radiance for detection range calculations (see section 1.5 above for an example). Paragraph 3.3. The developer shall create target library functions for TAWS in accordance with the design and concept of operation of TAWS version 4. The functions shall predict wake and target radiances over each combination of ships and speeds for detection range predictions in TAWS. The exercised idling (zero speed) state will be used in TAWS for identification, recognition, and lock-on range calculations. Paragraph 3.4. The developer shall create a modular object oriented computer code that makes MuSES capable of displaying and varying the thermal effects of the ship with the wake. This is useful for scene visualization and for validating the distribution of radiance among the facets. Paragraph 3.5. The developer shall provide status reports by email to the government technical representative for this task prior to each billing for services performed. Paragraph 3.6. The deliverables shall include: (1) library functions suitable for integration into TAWS for making detection range calculations utilizing the new wake models, and identification, recognition, and lock-on range calculations without wake effects for each of the two boat targets, (2) documentation for TAWS developers to integrate the new target/wake modules, (3) a complete and easily installable working copy of the most current version of MuSES that includes the wake effects describe above, (4) operating instructions for using MuSES that include the new wake features, (5) a report with technical descriptions and algorithms used for accomplishing this task, and (6) software source code and modules with instructions for compiling upon request. Paragraph 3.7. All delivered software modules will be Year 2000 compliant and consistent with the DIICOE level six goals for TAWS version 4. Paragraph 3.8. The developer shall provide technical problem support and bug fixes for six months following final acceptance of software. Paragraph 4.0. GOVERNMENT FURNISHED EQUIPMENT/MATERIALS. None. Paragraph 5.0. TRAVEL. None. Paragraph 6.0 OTHER. Paragraph 6.1 Security: SECRET GENSER. Much of the ship-wake hydrodynamics modeling effort is highly classified. The materials used for development of this task are SECRET. At least this level of clearance is required for communications and for CFD model operation. Additionally, it is possible that the output products of this task may be also be classified. The classification guidelines are outlined in the DD-254 form provided with this contract. Paragraph 6.2. Place of Performance: 100% contractor-owned facilities. Paragraph 6.3 Inspection and Acceptance: Technical Representative is: Mr. Charles P. McGrath, SPAWAR Systems Center, D858, 49170 Propagation Path, San Diego, CA 92152-7385, (619) 553-1416, DSN 553-1416, FAX 553-1417. Email address: mcgrath@spawar.navy.mil. Paragraph 6.4. Completion: Estimated at 6 months after date of award. Facsimile quotations may be sent to (619) 553-1062. Numbered Note 22 applies, however, all offers received within 7 days (in lieu of 45 days) after date of publication of this synopsis will be considered by the government. See numbered notes from any Monday edition of the CBD. The applicable North American Industry Classification System (NAICS) is 541330. Note: The full text of the Federal Acquisition Regulation (FAR) can be accessed on the Internet at http://farsite.hill.af.mil/. Offerors must complete and submit with their quote, a copy of FAR 52.219-1 Alt I/II, Small Business Program Representation.

Record

Loren Data Corp. 20010919/DSOL002.HTM (W-260 SN50X844)