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Executive Summary Developments in both information technology and in positioning technology are heightening expectations for significant cost reductions and major im- provements in acquiring, manipulating, and retrieving spatial data. Federal program managers have increasing needs and opportunities for analyzing data retrieved from diverse large spatial data files. The growing awareness of land and resource managers of the potential power of spatial analysis is increasing the incentive to integrate spatial data files. Early in this study the Committee on Integrated Land Data Mapping (ILDM) centered on the Public Land Survey System (PLSS) as a significant focus of federal interest and responsibility in the noncoordinate side of the coordinate-noncoordinate data dichotomy. The Committee reviewed the present status and importance of the PLSS with regard to both present federal lands and rights and the larger national interest in the PLSS on patented lands. The immense importance of PLSS corners and records in supporting property ownership rights in itself is sufficient grounds for perpetuating the system. Also recognized by the committee is the national tradition of the public's "right to know" both the identity of property owners or managers and the quality and quantity of the land. Also recognized is the extensive use of the PLSS as a noncoordinate spatial referencing system in coding natural-resource inventory data. Thus, it is evident that the value of the PLSS iS increasing with the passage of time. The Committee compared the values and uses of the PLSS with programs or activities established to maintain, develop, and improve the PLSS. There is widespread recognition that maintenance of the system is haphazard, and .^ l

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2 MODERNIZATION OF THE PUBLIC LAND SURVEY SYSTEM responsibility for this maintenance remains ill-defned and poorly exercised, even though the responsibility for monument maintenance is a statutory item in Mary states. Knowledge available to the public to relate ownership units to land quality is highly variable because of the variability of coverage and scale of land-quality data and the low positional accuracy of PLSS and parcel data. The Committee recognized two general areas of need for and interest in coordinate data for PASS corners, widely separated on a spectrum of posi- tional accuracy. At the coarse end of this spectrum is the community of users primarily involved in linking natural-resource records to base maps for pur- poses of spatial analysis. Their positional accuracy requirements are relatively well served by the National Map Accuracy Standards governing the 7.5-minute topographic series. Their needs apparently are served adequately by coordi- nates derivable from the National Cartographic Data Base at minimal cost. On the other hand, at the fine end of the positional-accuracy spectrum are users whose needs have been either unmet or met only by costly surveys. At the federal level this group consists of administrators and program managers, who must deal on a daily basis with uncertainties in the boundaries between federal and nonfederal lands that have the potential of diminishing the federal resource base and of litigation. The emerging positional technology promises to meet the needs of this latter group by improvements in accuracy accom- panied by dramatic time and cost reductions. Federal program administrators, together with a broad array of managers and others from both the public and private sectors, have an important on- going need to relate land qualities to ownership and jurisdictional entities. This spatial referencing and analysis, when directed by federal objectives, in- volves reference to the PLSS, with its vast population of township and section monumented and unmonumented corners. The deterioration of these PLSS corner monuments needs to be arrested. A comprehensive corner-mair~tenance program needs to be developed and implemented immediately. This mainte- nance program may involve the retracement of original surveys and re-estab- lishment of monuments. In addition, the PLSS together with federal cadastral surveying standards need to be modernized in order to transform positions of PLSS corners to a coordinate-based system tied to the national geodetic net- work. The emerging positioning technology will make the task of placing pre- cise coordinates on monumented PLSS corners possible at a reasonable cost. The needs for coordinate data for PLSS corners can be met most effec- tively by creating a national digital coordinate PLSS data base. This file should contain data-quality codes that would facilitate the progressive im- provement of coordinate data. The Department of the Interior should build such a file; should adopt data standards recommended for the multipurpose cadastre; and should, in cooperation with user groups, define the federal, state, and local responsibilities for the development and maintenance of the

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Executive Summary 3 file. Initially this file should be the responsibility of the Bureau of Land Management, and institutional arrangements should be made to encourage maximum participation of other federal, state, local, and private units in data- acquisition activities. This program should redirect the current federal cadastral surveying operations to the establishment of PLSS corner coordinates that meet recommended multipurpose cadastre standards. The file should also in- clude PLSS corner positions derived from the National Cartographic Data Base, with appropriate coding for data quality and source. This file should meet the near-term needs of a significant population of resource managers and scientists to relate data that are georeferenced to PLSS corners to a variety of coordinate-based data sets. In the longer term, the progressive upgrading of PUSS corner-position accuracy will contribute to the creation of a national multipurpose cadastre. Such a program would support the multipurpose cadastre in a cost-effec- tive manner, sharpen the spatial definition of areas falling under federal pro- gram administration, and facilitate the integration of diverse data files for spatial analysis by bridging the coordinate-noncoordinate dichotomy. As the need to assemble and relate data from various files increases, as the storage and retrieval of data in these files become more critical, and as the accuracy to which both of these tasks can be achieved gains importance, the disciplines of geodesy (particularly horizontal and vertical control), cadastral surveying, and cartography become more closely intertwined. This is particu- larly evident with the emerging interest in the development of geographic in- formation systems and, in particular, in the establishment of a national multi- purpose cadastre. Meeting the increased requirements for more accurate and up-to-date maps, charts, surveys, and land-related information is critical for the prudent use of resources and for the national defense. At the federal level, these activities are primarily the province of three separate agencies: the National Geodetic Survey of the National Oceanic and Atmospheric Administration in the Department of Commerce is responsible for the hori- zontal and vertical control networks, the Division of Cadastral Survey of the Bureau of Land Management in the Department of the Interior is responsible for cadastral surveying on federal lands and for the Public Land Survey Sys- tem on such lands, and the National Mapping Division of the U.S. Geological Survey in the Department of the Interior is responsible for the National Mapping Program. Such division of responsibility places an extreme burden on the close cooperation that is essential for an orderly and smooth develop- ment of the needed data files and maps. Therefore, this Committee endorses the recommendation of the Committee on Geodesy (1981) in the report Federal Surveying and Mapping that a Federal Surveying and Mapping Ad- ministration be established that would include these functions. Even before such an administration is formed, we recommend that an interagency working

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4 MODERNIZATION OF THE PUBLIC LAND SURVEY SYSTEM group be formed with participation of all relevant federal agencies and inter- ested groups at the state, local, and private-sector levels to integrate the geodetic, cadastral, and mapping activities necessary for the modernization of the Public Land Survey System. The Office of Management and Budget could encourage this kind of cooperative program by revising the scope of Circular No. A-16 to include cadastral surveying and incorporating in this circular mandatory compliance. The revision should provide the authority for effec- tive coordination of federal civilian programs for the modernization of the PLSS and should give recognition to the user community and to liaison with national engineering and scientific societies.