GIS Support
for
Survey Data
Caltrans District 5
Andy Richardson
Andy.Richardson@dot.ca.gov
Overview
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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
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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
Demo Survey Data Viewer
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 AddIn 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
DEMO
Control
Centerline Monuments
Property Corners
Alignments
• Centerline, Right of Way, Parcel
• Digital Alignment files
• .aln or .xml
• ArcObjects to convert
• View Related Docs
Add-In to download
& save file
• Paper records
• Co, Rte, PM stored
in DB
• Python to DynSeg
postmiles & buffer to
create polygons
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
DEMO
Scanned Maps
Field Books
• Python to DynSeg
postmiles & 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
DEMO
County Mapping
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
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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
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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?