***THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION'S (NOAA) ACQUISITION & GRANTS OFFICE, EASTERN ACQUISITION DIVISION-NORFOLK, NATIONAL OCEAN SERVICE (NOS) NATIONAL GEODETIC SURVEY (NGS) OFFICE, INTENDS TO NEGOTIATE AND AWARD A PURCHASE ORDER, ON A SOLE SOURCE BASIS, UNDER AUTHORITY OF RFO FAR 6.103-1, WITH THE UNIVERSITY OF NOTRE DAME FOR MODIFICATIONS TO THE DEPTH-AVERAGED WATER DENSITY ENGINE, ADVANCED CIRCULATION (ADCIRC), IN ORDER TO PROVIDE GLOBAL GRIDS (WATER LEVEL DATUMS) AND OTHER MULTI-YEAR WATER LEVEL PRODUCTS THAT WILL IMPROVE NOAA TIDALLY-REFERENCE AIRBORNE OPERATIONS. NO SET ASIDE IS TO BE USED FOR THIS SOLE SOURCE REQUIREMENT. THE ASSOCIATED NAICS CODE IS 541715. ***THE SOLE SOURCE DETERMINATION IS BASED ON NOAA'S REQUIREMENT THAT THE UNIVERSITY OF NOTRE DAME IS THE ORIGINAL DEVELOPER OF THE ADCIRC OCEAN MODEL AND NO OTHER VENDORS HAVE AN OCEAN MODEL PROGRAM THAT MEETS NOAA'S TIDALLY-REFERENCED AERIAL IMAGERY OPERATIONAL REQUIREMENTS. LONG-TERM HINDCAST MARINE GRIDS (AT DIFFERENT WATER LEVEL DATUMS) AND IMPROVEMENTS TO THE OCEAN MODEL WILL ALLOW INVESTIGATION OF APPROPRIATE TIME WINDOWS MONTHS AHEAD OF PLANNED FLIGHTS. IT WILL RELY ONLY ON ASTRONOMICAL TIDAL INFORMATION, WHICH IS AVAILABLE WITH MONTHS TO YEARS OF LEAD TIME. THESE REQUIREMENTS ARE MEANT TO INCLUDE FACTORS, SUCH AS ATMOSPHERIC FORCING MEANS THAT THE OBSERVED WATER LEVELS MAY DIFFER FROM PREDICTIONS. THEREFORE, TIME WINDOWS MAY ALSO DIFFER FROM THOSE CALCULATED WITH MODEL WATER LEVELS. THE STEPS REQUIRED FOR THE DEVELOPMENT INCLUDE: IDENTIFICATION OF APPROPRIATE DATA SOURCES AND OR MODELS. INTERFACE WITH EXISTING PACKAGE ARCHITECTURE. TESTING THE DEPTH-AVERAGED WATER DENSITY ENGINE, CALLED ADVANCED CIRCULATION (ADCIRC), WAS IDENTIFIED AS AN OPERATION READY OPEN-SOURCE MODEL ENGINE THAT CAN GENERATE TIDALLY-REFERENCE MARINE GRIDS. THE ENGINE ALREADY PROVIDES SHORT-TERM PREDICTION, AND HAS THE INFRASTRUCTURE TO GENERATE LONG-TERM HINDCAST PREDICTIONS (UP TO 20 YEARS) AND PRELIMINARY QUALITY CONTROL AT THE FIELD AND FINAL QUALITY CONTROL EVALUATION BACK IN THE OFFICE. BASED ON MARKET RESEARCH OF SUCCESSFUL WATER-LEVEL MODELS THAT ARE USED IN OPERATIONS AND ARE INDEPENDENT FROM GEOID MODELS IN NOAA AND IN THE U.S. ARMY CORPS OF ENGINEERS. WE WERE NOT ABLE TO IDENTIFY ANY OTHER OPEN SOURCE OR COMMERCIAL OCEAN MODELS THAT CAN PROVIDE THE MARINE GRIDS WITH GEODETIC CONTROL ACCORDING TO THE OPERATIONAL REQUIREMENTS NEEDED FOR TIDALLY-REFERENCED AERIAL OPERATIONS. THIS MODEL WAS DEVELOPED BY THE UNIVERSITY OF NOTRE DAME. THE TIDALLY-REFERENCED MARINE GRIDS FROM THE IMPROVEMENT WATER MODEL (WITH RESPECT TO THE ELLIPSOID) MUST BE COMPATIBLE IN ALL ASPECTS (FILE FORMAT, EPOCH, AND SPECIFIC TIDAL STAGE) WITH THE EXISTING OPERATIONAL FRAMEWORK USED FOR AERIAL OPERATIONS. THE ADCIRC MODEL IS UNIQUELY QUALIFIED TO MEET THESE REQUIREMENTS BASED ON PROOF OF CONCEPT TESTING; INTEGRATION OF THE SHORT-TERM ADCIRC MODEL INTO THE NGS AERIAL OPERATIONS FRAMEWORK HAS BEEN SUCCESSFUL. …