Use of Advanced Geospatial Data, Tools, Technologies, and Information in Department of Transportation Projects (2013)

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55 Many agencies [FGDC 1998; National Digital Elevation Pro- gram (NDEP) 2004; NOAA 2010; FAA 2011; USGS (Heid- mann 2012)] have provided recommendations, guidelines, or standards for delivering geospatial data. However, given the rapid pace of technology development, the trend is to develop guidelines that enable flexibility as technologies evolve, rather than rigid standards that may stifle innovation. In addition, many standards remain in draft form, rather than being offi- cially released as a final document owing to the time and effort necessary for their creation. Performance-based standards and guidelines are becoming increasingly common because they can ensure the desired results are obtained, while still enabling flexibility in how the work is done. Technical documents that provide help to develop quality management procedures can be categorized as follows (in order of increasing rigidness): 1. White papers, technical documents 2. Best practices 3. Guidelines 4. Specifications 5. Standards Several organizations are involved in general standards creation, including • American National Standards Institute, www.ansi.org • ANSI INCITS L1—Geographic Information, www. incits-l1.org/ • ASTM international, www.astm.org • Federal Geographic Data Committee Standards, www. fgdc.gov/standards • Federal Emergency Management Agency, www.fema. gov • United States Geological Survey, www.usgs.gov • General Services Administration, www.gsa.gov • International Standards Organization, www.iso.org • ISO Technical Committee 211—Geographic Informa- tion, www.isotc211.org/ • National Institute of Standards and Technology (NIST), www.nist.gov • Open Geospatial Consortium, www.opengeospatial.org • Standards Setting Organizations, www.consortiuminfo. org/links/ • Standards.Gov. standards.gov (Note: This list was modified from ASPRS.) In addition, several agencies have created internal stan- dards, guidelines, and best practices to suit their needs (Table 24). Often these documents are used as reference by multiple other agencies, outside of their original intent owing to the time and effort necessary to develop the documents for each organization. In addition, many state DOTs (as dis- cussed in chapters two and three) have developed their own standards and manuals to fit their needs (Table 25). Note that some form of geospatial standards were found for 38 of 50 (76%) state DOTs. This compares well with the results of the DOT questionnaire, in which 75% of the DOTs indicated that they had available standards. However, note that this does not indicate that the standards cover advanced technologies for all of the DOTs. Just as it is difficult for national standards to keep pace with technologies, many transportation agencies are struggling to produce adequate standards for some of the newer technologies. Common themes and needs among documents include: 1. Verify geometric accuracy (and in some cases, clas- sification accuracy). 2. Provide appropriate deliverables. 3. Provide documentation showing a lineage for the data that documents data manipulation from acquisition to processing. An important consideration is that QA/QC procedures that have worked in the past may not work with newer technologies. Given the large size of the data sets, it becomes increasingly difficult to detect errors. Certification sites are one possibility that has received attention: 1. National Centers for Coastal Ocean Science (NCCOS), NGS, NOAA, National Park Service (NPS), and USGS have created a bathymetric mapping test site in the U.S. Virgin Islands. 2. The NGS maintains a LIDAR calibration site in Virginia. 3. Utah DOT has established a certification site for a recent Mobile LIDAR request for services. The agency also required an independent QA/QC firm for the certi- fication and project. GEOSPATIAL DATA ACCURACY The Federal Geographic Data Committee (1998) developed the National Standard for Spatial Data Accuracy (NSSDA), which provides guidance for reporting spatial data accuracies, chapter seven QUALITY MANAGEMENT PROCEDURES

56 including the need for confidence intervals. This document provides the backbone for reporting in most available stan- dards and guidelines. The NSSDA uses a root mean square error to estimate positional accuracy. However, the accura- cies are reported in ground distances at 95% confidence. Data sets should be tested with a minimum of 20 control points and reported as: Tested ____ (meters, feet) vertical (or horizontal) accu- racy at 95% confidence level However, in cases where the data were not tested but accuracy merely has been estimated, the following statement is used: Compiled to meet ____ (meters, feet) vertical (or horizon- tal) accuracy at 95% confidence level The National Data Elevation Plan (Guidelines 2004) was developed by representatives from several federal organiza- tions to provide guidance on digital elevation data in various forms. These guidelines further developed the concepts of the NSSDA to include three types of accuracy reporting: fun- damental vertical accuracy (open terrain, best conditions), consolidated vertical accuracy (combined accuracies for all land covers), and supplemental vertical accuracy (accuracies reported for individual land covers). It also provides guid- ance on integrating bathymetric data and modeling hydro- logic features (e.g., culverts under roadways). Technology Published Documentation Pending Documentation Geospatial • FGDC-STD-007.3, 1998 • NDEP, 2004 • ASPRS procurement guidelines, 2009 • ASPRS procurement, 2011 • FAA Advisory Circular 150/5300-17C, 2011 CAD • USDA\USFS CAD standards manual, 2010 GIS • OGC Standards (various) • GSDI Cookbook (Wiki) • International Organization for Standardization (ISO) Technical Committee 211 (TC 2110) • ASPRS Style Guide for GIS, 2007 • ASPRS Manual of GIS, 2009 GPS • USDA\BLM, Cadastral surveys using GPS, 2001 • NOAA Technical Memorandum NOS NGS 59 GPS-derived Orthometric Heights, 2008 • NGS CORS guidelines • USFS GPS data accuracy standard, 2003 • FGDC, Geometric Geodetic Accuracy Standards for GPS, 1989 GPR • AASHTO PP40-00 • NTIA, 2011 • AASHTO TP36, 1993 • ASTM D6432-11 • ASTM D6087-08 • ASTM D478-10 LIDAR • ASPRS LAS format V1.4, 2011 • ASPRS Vertical Accuracy for LIDAR (airborne), 2004 • ASTM E57 3D imaging exchange format • NOAA SOW Airport Surveying, 2009 • FEMA’s Mapping and Surveying Guidelines and Specifications • USGS-Base Specification v1.0 • NCHRP 15-44—Mobile LIDAR for transportation applications • ASPRS Mobile Mapping Committee • ASPRS Horizontal Accuracy for LIDAR (airborne), 2004 • ASTM E-57 • NOAA SOW Shoreline Mapping, LIDAR, 2009 (DRAFT) • ASPRS Airborne Topographic LIDAR Manual Automated Machine Guidance • NCHRP 10-77—Use of Automated Machine Guidance (AMG) within the Transportation Industry Photography Imagery • ASPRS (Photogrammetry) • NOAA Shoreline Mapping, 2004 • U.S. Army Corps of Engineers Surveying • NGS, Benchmark Reset Procedures, 2011 • NGS CORS Site Monumentation, 2006 • FGDC Standards and Specifications for Geodetic Control Networks Note: Many titles have been abbreviated. TABLE 24 CURRENT AND PENDING GEOSPATIAL GUIDELINES

57 GENERAL REMOTE SENSING GUIDELINES The FAA has produced a draft Advisory Circular discuss- ing remote sensing technologies for airport surveys (specifi- cally, aerial imagery, digital orthoimagery, LIDAR, satellite imagery, and subsequent deliverables). PROCUREMENT GUIDELINES ASPRS has produced a draft document to help entities with the best approach to commercial geospatial products, defined with a COTS specification. The document distinguishes between professional/technical services and commercial geospatial products. It also recognizes state and federal laws. A proposed procurement methodology of license data terms and condi- tions, cost/value, service provider-defined technical specifica- tion, services to support geospatial products, and deliverables are covered. LIDAR GUIDELINES Because LIDAR technology has been evolving rapidly, there are limited standards and specifications in place. Currently, the industry tends to favor guidelines to provide leeway for future technological developments. A key challenge with LIDAR is data management and storage. Although data formats for other geospatial technologies have been stan- dardized through CAD and GIS, work is still in process to standardize LIDAR data for delivery and exchange. Two important efforts are the ASPRS LAS and ASTM E57 data formats. Relevant information sources regarding LIDAR acquisition and processing are listed here. Note that many are in draft form and are meant as guidelines to support future changes in the technology. Many are specific to airborne LIDAR, whereas others can be applied to multiple LIDAR platforms. • ASPRS vertical accuracy guidelines for airborne LIDAR (draft). This document reinforces the NSSDA and NDEP guidelines and provides guidance for establishing control specific to airborne LIDAR. • ASPRS horizontal accuracy guidelines for airborne LIDAR (draft). This document provides background on the difficulties in determining horizontal accuracies from airborne LIDAR. • The USGS developed base LIDAR specifications (air- borne focus) focused on accuracy, resolution, and clas- sification of LIDAR data for mapping purposes. TLS = terrestrial laser scanning. State Survey LIDAR Photo GPS State Survey LIDAR Photo GPS AL MT X X X AK NE X AZ X X X X NV X X X AR X X NH X CA X TLS X X NJ X X X CO X X X NM X X CT X X NY X TLS X X DE NC X X X X FL X X ND X X X GA X X X X OH X X X HI OK X X X ID OR X X X X IL X X X PA X TLS X X IN X X X RI IA X SC X X KS X SD X X X KY X X X TN X X X LA X TX X X ME UT X MD VT X MA X VA X X X MI X X X WA X X X MN X X WV MS X WI MO X X WY X X X TABLE 25 STATE REFERENCE MANUALS AVAILABLE ONLINE

58 • The ASPRS Mobile Mapping Committee is developing guidelines for mobile mapping systems. This document is a work in progress at the outline stage. • A current NCHRP project (15-44) is under way to develop performance-based, technology neutral guide- lines for the use of Mobile LIDAR in transportation appli- cations. This project will be completed in March 2013. These guidelines will be applicable to a wide range of transportation personnel. • The FAA circular mentioned previously includes a section discussing considerations for the use of several forms of LIDAR (static, mobile, and airborne) for air- port surveys and anticipated accuracies and resolutions for each form. • Chapter 15 of the Caltrans (2011) Surveys Manual is one of the first developed sets of specifications that explicitly addresses the required information and data quality that should be provided with a static or Mobile LIDAR survey. The Florida DOT (2012) has adapted this document into a draft document. • ASPRS has developed the LAS format for LIDAR point cloud exchange. This is the de facto standard for- mat in the airborne LIDAR industry. This format sup- ports classification schemes and metadata for the point cloud. A recent development, LASzip, enables a signifi- cant reduction in required storage space for archiving point cloud data. • The ASTM E57 subcommittee has developed an exchange format for 3D imaging systems. This format is being adopted as an exchange and archive format for static and mobile laser scanned data. • Knaak (2012) has developed a set of best practices for Mobile LIDAR project requirements based on consult- ing experience. The document defines three distinct lev- els of data collection as well as requirements for vehicle trajectory, point cloud, file management, and images.