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

A -- ADVANCED DEVELOPMENT OF HARDWARE FOR TESTING, ENGINEERING DEVELOPMENT SOL N66001-00-Q-A160 DUE 040700 POC Purchasing Agent, Melissa Dolan (619) 553-6336, Contracting Officer, Sylvia Proffit (619) 553-3292 This is a combined synopsis/solicitation prepared in accordance with FAR Part 13. NoRFQ will be prepared or made available for distribution. The government intends to award, on a Sole Source basis, an order to Science & Technology Corporation for the following tasking: AEROSOL Modeling. BACKGROUND: Marine Aerosol Modeling Electrooptic (EO) systems represent a critical Navy technology for detection or identification of high precision, low-intensity, easy to launch anti-ship weaponry. As the operational scenario of the Navy changes to include more coastal regions, it finds itself increasingly more exposed to the threat of sophisticated short-range, low-flying missiles. It is imperative to know the effects and impact of the atmosphere on EO systems to ensure that EO systems under development will perform as expected. The aerosol modeling effort addresses the investigation, development, and evaluation of these ocean and coastal aerosol models and evaluates their effects on IR propagation. One such aerosol model is the Navy Aerosol Model (NAM). NAM is the core aerosol model used in the LOWTRAN / MODTRAN propagation codes. It was developed utilizing aerosol size distribution measurements made at shipboard heights and represents aerosols at that height.The Navy Oceanic Vertical Aerosol Model (NOVAM), an extension of NAM, models the vertical profiles from shipboard upward. NOVAM has been incorporated into the MODTRAN propagation code. The Advanced Navy Aerosol Model (ANAM) was developed as an extension of the NAM/NOVAM to account for aerosols near the ocean surface. An extension of these models to include the effects of aerosol produced by the breaking surf on the total aerosol over the coastal regions of the ocean (Coastal Aerosol Model, CAM) is to be planned and build based on the set of experiments known as EOPACE. This model must include the effect of fetch, swell, and wind direction and perhaps sea bottom characteristics as well as the other normal meteorological measurements needed in the NAM/NOVAM/ANAM family of models. Sub-Stratus Aerosol Cloud Modeling Another such aerosol model is the Sub-Stratus aerosol model. The primary sources of infrared (IR) sky radiance backgrounds affecting system performance are thermal emissions of the atmosphere and scattered radiation from suspended particulate (aerosols). Previously, an aerosol model was developed for use in the codes to describe the far IR wavelength band beneath stratus clouds. In this effort, the wavelength dependent extinction and absorption coefficients (normalized to the 0.55 micron scattering coefficient) and the asymmetry factors were described by a multiplying array for four different altitude regions of the stratus regime. This model (while not yet transitioned into the computer codes) provided near a factor of 3 better agreement between measured and calculated performance ranges than did the default stratus models presently available in the codes. A similar model for the mid-IR band was developed and initial evaluation performed. Extended evaluation of sub-stratus cloud aerosol model for both the mid- and long-IR bands utilizing the SSC-SD EOPACE database needs to be performed. SCOPE: Marine Aerosol Modeling. Analyze the SSC-SD EOPACE database of aerosol size distribution data from pier, boat and shore and develop a first-cut CAM model to lead to a transition into the propagation codes. Evaluate the modifications to NOVAM and incorporate the changes into the MODTRAN propagation code. Sub-Stratus Aerosol Cloud Modeling . Evaluate the sub-cloud aerosol model for both the mid- and long-IR bands utilizing the existing SSC-SD database. TECHNICAL REQUIREMENTS: Marine Aerosol Modeling Evaluate/analyze the EOPACE database for the development of a coastal aerosol model (CAM) including: 1) analysis of the Duck NC database, 2) wave/surf aerosol generation/transport, and 3) sea bottom effects on aerosol production. Build an advection component for the surf aerosol model, in cooperation with the effort by TNO (Netherlands). Prepare a final report on: 1) NOVAM modification evaluation, 2) analysis of the Duck NC database for wave/surf aerosol generation/transport (including sea bottom effects), and 3) the progress of developing an advection component for the surf aerosol model. Sub-Stratus Aerosol Cloud Modeling: Evaluate the sub-cloud aerosol model for both the mid- and long-IR bands utilizing the existing SSC-SD database and document findings. GOVERNMENT FURNISHED EQUIPMENT/MATERIALS Access to NAM/NOVAM/ANAM aerosol codes and the SSC-SD EOPACE databases used for model development. The government will provide the contractor access to information and documentation (relative to the requirements, procurement, integration, testing, and evaluation) within 10 days of receipt of contractor's request. Contractor will have access to necessary SSC-SD computer facilities, thermal-imaging systems, databases and appropriate computer hardware and software. TRAVEL: Travel to technical symposiums to present papers as designated and approved in advance by the COR. Estimate one trip, one person, three days, San Diego, CA, to Washington, DC. OTHER: Security: This task is unclassified. Place of Performance: SPAWARSYSCEN San Diego D858, located in Bldg. 323, San Diego, CA. Inspection and Acceptance: Technical Coordinator: Dr. D. R. Jensen, Code D858, (619) 553-1415. COR: N. M. Vorce, Code D8502, (619) 553-3054. Period of Performance: Estimated at six 6 months from date of award. NOTE: The above tasking is intended to be awarded in the Simplified Acquisitions arena to act as a bridge until formal contract is awarded. RFP N66001-00-R-5019 will be issued in April 00 on a competitive basis. Interested parties should refer back to the CBD at that time for information regarding that solicitation. Facsimile quotations (for this bridge only) may be sent to (619) 553-1062. Questions may be directed to Melissa Dolan (619) 553-6336, email: dolanm@spawar.navy.mil. Note 22 applies, however, all offers received within 15 days (in lieu of 45 days) after date of publication of this synopsis will be consideredby the government. See numbered notes from any Monday edition of the CBD. The applicable Standard Industrial Classification Code and Size Standard is: 8731/500 employees. 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 52.219-1 Alt I/II, Small Business Program Representations. Central Contractor Registration is required for resulting award. Information may be found at http://www.ccr2000.com/. Posted 03/20/00 (W-SN436298). (0080)

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