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FEDERAL GEOSPATIAL SUMMIT MAY 11, 2010 SILVER SPRING, MARYLAND PROBLEMS AND SOLUTIONS DURING THE NAD 83 & NAVD 88: LOOKING BACK. JOHN D. BOSSLER REAR ADMIRAL NOAA (RET.), PROFESSOR EMERITUS, OHIO STATE UNIVERSITY. IN THE SEQUEL. FINANCIAL PROBLEMS TECHNICAL PROBLEMS USER PROBLEMS
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FEDERAL GEOSPATIAL SUMMIT MAY 11, 2010 SILVER SPRING, MARYLAND PROBLEMS AND SOLUTIONS DURING THE NAD 83 & NAVD 88: LOOKING BACK JOHN D. BOSSLER REAR ADMIRAL NOAA (RET.), PROFESSOR EMERITUS, OHIO STATE UNIVERSITY
IN THE SEQUEL • FINANCIAL PROBLEMS • TECHNICAL PROBLEMS • USER PROBLEMS • INTERESTING USER EXAMPLE • BOSSLER ON REDEFINITIONS
FINANCIAL PROBLEMS P: OVERALL INITIAL BUDGET WAS INADEQUATE S: BEGGED TOWNSEND and CALIO FOR MORE MONEY P: COST OVERUNS ON SOFTWARE AND DATA CONVERSION S: RESULTED IN 50% CONTRACTS AND IN HOUSE P: KEY ALL THE DESCRIPTIONS? S: USE CONVICTS TO KEY DATA P = PROBLEMS S = SOLUTIONS
TECHNICAL PROBLEMS P: ROUND OFF ERRORS S: PETER MEISSEL CAME TO NGS FOR A YEAR P: TOO MANY EQUATIONS S: REDUCED SPACE NEEDED (R.SNAY) P: CORRECT WEIGHTING NEEDED S: VARIANCE COMPONENT STUDY (TEAM OF B. CARTER, E. MCKAY, ET AL)
TECHNICAL PROBLEMS P: CORRECT ITERARTION OF EQUATIONS S: USED “PITFALLS” (A. POPE, J .ISNER) P: GEOID REFINEMENT AND ENHANCEMENT S: GATHER NEW DATA, R & D ON METHODS (TEAM OF B. STRANGE, T. SOLER, R. FURY AND C. GOAD) P: DATA MANGEMENT S: BACKUP AT HOME, DEVELOPED PROCESS (L.WADE, G. YOUNG, M. VORHAUER)
USER PROBLEMS P: SURVEYORS DIDN’T UNDERSTAND S: HELD USER MEETINGS AT NGS, CONFERENCES P: USGS AND OTHER FEDS SLOW TO ACCEPT S: COMPUTED ESTIMATED MAP CORNERS P: C&GS RESISTED S: CREATED A SCHEDULE CHANGING NAD 29 TO 83
NAVD 88 MANY PROBLEMS WERE SOLVED in NAD 83, DESCRIPTIONS, SOFTWARE, HELMERT BLOCKING, ETC P: MONEY PROBLEMS EXISTED S: TOOK FROM C & GS, TOWNSEND P: TECHNICAL PROBLEMS STILL EXISTED, E.G., ORIGIN S: SOLVED BY C. WHALEN, D. ZILKOWSKI, G. YOUNG
AN INTERESTING CONSULTING CASE • SMUGGLERS CROSSED FROM CANADA TO THE STATE OF • WASHINGTON. OVER THE BORDER? • PUBLIC DEFENDER ASSERTED THAT SMUGGLERS WERE • 800 FEET INTO CANADA ACCORDING TO GPS • STUDIED ZENITH TELESCOPES, METHODS, ETC. COULD NOT • FIND ERRORS = TO 800 FEET. WENT TO COURT • BEFORE I TESTIFIED, I USED INTERNET, GOT DEFLECTION • FROM NGS. IN THE MERIDIAN PLANE IT WAS 800 FEET
REDEFINITION OR NOT? • VERTICAL DATUM MOST IMPORTANT BECAUSE OF GPS AND • ACCURATE GEOID. THIS STRATEGY WILL PREVAIL. • USER CONSTANCY IS PREMIER • ACCURACY, ESPECIALLY ABSOLUTE POSITIONING, IS • SECONDARY. • NEW NGS PARADIGM(GPS) IS GREAT