GIS Project Experience
American Disabilities Act (ADA) Ramp Location
GPS Data Collection & Mapping
FM 1717
SUE & GIS Conversion of SUE Data
City of Gonzales
Utility Locating & Mapping
North Cascades Glacier
Planimetrics / DTM / DEM Comparison
American Disabilities Act (ADA) Ramp Location
GPS Data Collection & Mapping
SAM, Inc. developed the project plan for a GPS field asset inventory of ADA ramps within the TxDOT right-of-ways within the Austin District, approximately 731 miles of roadway. This project plan included defining the scope of work, data capture procedures, equipment standards, training, and other requirements necessary to collect the required ADA ramp information within an 11 county area. SAM, Inc. also developed and tested the Data Dictionary used to collect up to 60 data features for each ramp.
SAM, Inc. served as the overall project coordinator directing the efforts of 7 additional survey consultants. With combined resources we were able to field 21 survey crews. This project required the collection of specific information for a district-wide inventory of intersections and ramps. This information allows TxDOT to assess and prioritize intersections and ramps that must be upgraded to be in compliance with the American Disabilities Act Pedestrian Accessibility Project.
As part of the data collection process SAM, Inc. established an FTP site. Each survey crew downloaded their daily data collection efforts to this site. SAM, Inc. technicians then processed and performed quality control of all data collected by the survey consultants to include Trimble Pathfinder Pro data dictionary .SSF data files and .JPEG format image files. SAM, Inc. performed QA/QC procedures and notified the survey consultants of any problems or necessary corrections. After the QA/QC was performed, the data was appended to a master set of files in ARCGIS 8. As part of this process the images were linked to the feature data using the hyperlink tool in ARCGIS 8.
SAM, Inc. also determined Texas Reference Marker and displacement information and added this to the feature data for all corners located. This data was determined using either digital or hardcopy RI-1 (Road Inventory) data provided by Austin District - TxDOT.
FM 1717
SUE & GIS Conversion of SUE Data
This project consisted of approximately 15,900 linear feet of existing storm drainage systems, electric distribution, communication, fiber optic systems, cable TV, nature gas, water, and wastewater systems. SUE Quality Levels B & A and GIS services were provided.
SAM, Inc. provided Subsurface Utility Engineering services that identified, designated and mapped (QL-B services) the existing utilities for this project. Once the design engineer with TxDOT reviewed the information presented, seven (7) test hole locations (QL-A services) were determined for obtaining vertical information on the storm drainage system.
GIS services for this project were developed to give the client faster access to utility information by converting MicroStation .dgn files to ESRI shapefiles using Arc Map 8.3. The shapefiles were then split into numerous layers to separate the various utilities found. The utility layers were then attributed with pertinent information such as: owner of utility; contact name; phone number; address; size of utility; utility status (active/inactive/abandoned), copy of permit and date issues; copy of record or as-built information received from the utility company, utility encasement material found, and test hole reports for line segments.. A road and feature base layer (provided by TxDOT) served as a background reference for the underground utility information collected in the field.
Permit records, as-built information and test hole reports were hyperlinked to all utility line segments to allow the user to click on an object to bring up linked utility information.
City of Gonzales
Utility Locating & Mapping
SAM, Inc. collected all utility features as specified by the Lower Colorado River Authority for the City of Gonzales . SAM, Inc. developed a data dictionary using Pathfinder Office software to enable GPS data collection crews to collect features and attributes that included fire hydrants, water valves, manholes, and paint stripe markings placed by the City of Gonzales utility personnel indicating underground water and wastewater lines.
Sub-meter accuracy positions were collected for features using a Trimble ProXRS Mapping-grade GPS receiver with OmniStar subscription. SAM, Inc. GIS technicians provided QA/QC of the feature data. Data was process using Pathfinder Office software with feature coordinates in Texas State Plane – Central Zone – Grid. Units were in US Feet. Feature data was exported into an ArcMap database file. Original hardcopies of the utility system maps were scanned and geo-referenced to the project coordinate system for use as base mapping for this project.
North Cascades Glacier
Planimetrics / DTM / DEM Comparison
North Cascades Glacier Project located in the North Cascade National Park, Washington. SAM, Inc. derived control values from USGS 7.5' quadrangle maps to control color aerial photography provided by the National Park Service. Project coordinate values were based on North American Datum 1927, UTM Zone 11 North, Meters. Vertical control was based on National Geodetic Vertical Datum 1929.
Digital Aerial-Triangulation software was used to perform fully digital aero-triangulation on color images for the four project areas. Softcopy workstations were used to collect the planimetric feature data and DTM data suitable for producing 1-meter contours. SAM, Inc. converted historic USGS Raster DEM files to Arc Shapefiles, then used ArcMAP 3D analyst to create surface TIN files. Final comparison of historic data sets and current data sets was performed using ArcMap Spatial Analyst to derive volume change values. SAM, Inc. produced thematic maps showing volume changes over 10-meter elevation bands.
