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GIS Support for Survey Data. Caltrans District 5 Andy Richardson Andy.Richardson@dot.ca.gov. Overview. Role of GIS in Caltrans D5 Surveys Survey GIS Viewer Datasets included in GIS Viewer Role of Surveys Database End user tools included in the viewer
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GIS Support for Survey Data Caltrans District 5 Andy Richardson Andy.Richardson@dot.ca.gov
Overview • Role of GIS in Caltrans D5 Surveys • Survey GIS Viewer • Datasets included in GIS Viewer • Role of Surveys Database • End user tools included in the viewer • Data conversion and processing tools
Role of GIS in Surveys • Primarily as an index to survey data • Tools to view and search for available survey data • Secondarily as a mapping tool • Generally for the purposes of providing maps to field surveyors to help located control, or for mission planning • Users • Primarily Survey staff • Also Design and other staff
Index to Survey Data • Survey data • Caltrans • Local agency • Reference data • Aerial photos • Highways • Postmiles • Streets • Custom tools • Hyperlinks • Exporters • Reports
Tools • VB.NET ArcObjects • Standalone executables for data conversion • Add-Ins for end user ArcMap tools • Python • For data conversion • Standalone scripts • Some have forms • ArcMap tool scripts • Easier to create a generic form
Staff • Jim Weirick (Surveys) • Took initiative years ago to start cataloging Surveys data • Relentless push to make this happen • Superhuman ability and willingness to do grunt work • Andy Richardson • All GIS development • Surveys Management • Provide resources and support • Select Surveys staff • Provide some of the labor to compile data, including acquisition of external data • All Surveys staff • Acceptance/adoption of tools, constructive feedback, promotion
Surveys Database (Access) • Master data catalog • Most current • Maintained daily by Jim Wierick • Source of all attributes • All converters pull information from here
Data Conversion • Sources of Data: • Eastings and Northings • Alignment files (.aln, .xml) • County, Route, Postmile references • Scanned maps • Conversion Tools: • VB.NET executables • Eastings/Northings • Alignment files • Python (ArcGIS) scripts • Dynamic Segmentation • Join attributes from Access • Copy GIS datasets to library • Manual • Georeference scanned maps • Digitize footprints • Store as File Geodatabase Feature Classes
Control & Property Corners • Data stored in Access • Northings and Eastings • VB.NET executable to convert to Feature Classes • Export to CSV Add-In to export selected features to Excel
Control & Property Corners • Python script to create template Feature Class • Python script to copy staged Feature Class to GIS Library
Alignments • View Related Docs Add-In to download & save file • Paper records • Co, Rte, PM stored in DB • Python to DynSegpostmiles & buffer to create polygons • Centerline, Right of Way, Parcel • Digital Alignment files • .aln or .xml • ArcObjects to convert
Scanned Maps • Georeferenced • Footprints Index layer • View Docs tool to add map to display or view as PDF • Surveys staff has georeferenced 1000’s of maps • Each map gets a footprint • Python scripts help ensure integrity among datasets
Field Books • Python to DynSegpostmiles & buffer to create polygons • View Docs Add-In to view PDF
County Maps • Various formats provided by various counties • Some maps stored on web site, others delivered • Index footprint layer also necessary • View Docs tool for most, custom tool for SLO County
Additional Datasets • Caltrans Survey • Survey RW Engineering • Python to postmile • View Docs tool to view PDF • RTK Calibrations • Digitize footprint • View Docs tool to view PDF or download data file • Other Caltrans data • Culvert Systems • State Highways • including old/former • Postmiles • Other reference data • Aerials • Scanned USGS Quads • Public Land Survey • Ranchos, Townships, Sections • Parcels • Streets, Rail • Cities, unincorporated areas, counties
Data Storage • Linked Source Data • Stored on network • Organized by theme, county • Easily referenced by Access and GIS links • Resulting GIS Data • Stored in GIS library • Very organized
Dynamic Segmentation(postmiling) • Method for converting tables containing County, Route, and Postmile(s) into GIS points or lines based on location along state highway • Requires reference linework (routes) with measures (postmiles) • AKA a Linear Referencing System (LRS) • Requires application to perform DynSeg • Python used for survey converters • Points and lines are buffered to create polygons • Resulting polygons are coded with Access attributes, and generally have links to related documents • Polygons are generally stacked on top of each other, representing multiple data in same locations
Tools – ArcObjects Add-Ins • Written in VB.NET or C# • Used for end-user ArcMap buttons and tools • Much faster and more professional than Python • Very highly functional forms • Add-Ins don’t require install program or DLL registration for each PC • This was a problem prior to Add-Ins • We have established an Add-In network folder • Each PC gets this registry setting as a part of ArcGIS install • Result is that buttons and tools added to an ArcMap document are automatically there for all District GIS users
Tools – Surveys Add-Ins • View Related Documents • Export Control to CSV • Export Display (georeferenced) • Change Data Frame Coordinate System • Report Display Coordinates • Export to CAD (Microstation or AutoCAD) • Locate County Parcel (by APN) • Locate Caltrans Parcel (by parcel #) • View non-Geographic Documents • View Reports • Page Setup
Tools – ArcObjects Executables • Written in VB.NET or C# • Used when performance or functionality is needed • Control2GIS • Need greater performance to converts thousands of points • Alignments2GIS • Need greater functionality to read .aln or .xml files
Tools - Python • Much simpler/quicker development than ArcObjects • Great solution for small and knowledgeable user base • We use for: • Template Feature Class creation • Conversion of smaller datasets to GIS format • Copy staged Feature Classes to GIS library • Standalone • Run from Python editor or DOS • ArcMap tool script • Very easy to create input form • Standalone with Python form • Why use ArcMap just to get an input form? • Python forms are a bit hokey though
Export Tools (planned) • Primarily to support external customers • Currently performed on an Ad hoc basis • Plans to develop Python tools to automate • Pick a county… • Copy datasets and supporting documents to staging folder • Transfer folder to requestor
Limitations • Using Access and not a multi-user database • SQL Server, PostgreSQL? • Not using a web-based solution • Current Caltrans solution is Google Earth • ArcGIS Server/ArcGIS Online? Open source? Image Services for aerials? • No web-based access to data • Georeferenced images stored on internal file server and not on external web server • Web Feature Services (WFS) to support external customers?