Aerial Mapping & Topographic Surveys
Large scale mapping and photogrammetric projects have used GPS technology to economize the cost of ground control. Airborne GPS (ABGPS) greatly reduces the amount of costly ground control. By adding a precise GPS receiver to the aircraft and one or more base receivers occupying known control points on the ground, precise photo center coordinates can be obtained. ASE supports your mapping project with Airborne GPS, collection of data, and processing of photo centers.
- Conventional Site and Corridor Mapping
- Digital Aerial Mapping, Digital Orthoimagery (DOI)
- Airborne GPS Controlled Mapping
· Cook County Aerial Mapping. As a survey subconsultant to Merrick & Co., ASE provided Horizontal and vertical GPS control surveys for aerial photos covering Cook County. We supplied coordinate NGS points to Illinois State Plane and provided ground crews to assist with support of Airborne GPS data acquisition. We recovered, photo targeted (paneled) and surveyed 46 existing NGS points.
ASE (as a subconsultant to Merrick) provided aerial photogrammetric control paneling, recovered 43 existing and placed of 82 new photo control points. Horizontal and vertical control surveys we achieved by GPS, including network design, observations of 82 new and 5 replaced points, GPS data processing with control dossier, report with data conforming to FDGC Metadata standards. Also provided ground support for Airborne GPS and surveyed 3D positions for all photo centers. ASE provided ground-truthing surveys sufficient for all project locations.
ASE and Merrick have been re-contracted on a periodic basis to update, maintain and improve the Cook Co. photo mapping and control. We are in the process of completing the 2009 installments of this important project.
· Aerial LiDAR of I-355 South Extension As-Built. After completing construction on the new I-355 South extension from I-55 to I-80, the Tollway contracted Aero-Metric to perform as-built mapping with aerial LiDAR. In support of the aerial mission, ASE provided GPS ground observations during the flight from two control stations. In addition, ASE provided ground truthing of the LiDAR results by performing cross sections at ten locations and checked ten horizontal and vertical control points.
· Minneapolis/St. Paul MN Airborne GPS. Central corridor route study for commuter rail system in Ramsey and Hennepin Counties, Minnesota. Tasks included GPS control to set 9 check points and set 2 base stations, airborne GPS mission, process photo centers and verification of aircraft, camera center and antennae center at flight attitude.
· Lake County (IL) Photogrammetry/GPS. ASE was the ground surveying subconsultant to Merrick & Co. on this photo mapping project. ASE provided aerial photogrammetric control paneling and recovery of photo control points for countywide mapping project. We paneled and observed every 1st order control point within the county and then densified horizontal and vertical control by GPS including network design, observations of existing control points, replacement of missing points, paneling for all control, delivery of control dossier and data file using FDGC Metadata standards. ASE and Merrick have been re-contracted on an annual basis to update, maintain and improve the photo mapping and control for this project.
· City of Lake Forest GPS/Digital Orthophotography/DTM. ASE was the ground surveying consultant on this photo mapping project for the City of Lake Forest. We provided control for development of Digital Terrain Model in Lake County, Illinois. We provided recon and recovered 43 existing City benchmarks, set 30 new semi-permanent control points and 18 new permanent concrete monuments; target all 91 points. We occupied 10 existing control points to ensure that new points tie into existing system. Horizontal GPS control to 1:100,000; vertical GPS to within one-tenth (0.1) of a foot. One hundred percent redundant observations were included in network configuration. Extra work included an additional 29 benchmarks requiring GPS observations.
· AT&T Aerial Photo Control Project. ASE coordinated the subconsultants for aerial photography & computer training. We also provided ground control by GPS technology and established a coordinate system. Project also required cadastral and photogrammetric mapping. ASE delivered digital orthoimagery and topographic mapping. ($38,025).
· Camp Shelby, Mississippi. ASE was ground surveying subconsultant to Polyengineering for GPS surveys for multipurpose artillery range complex to Order 2(2-II) for aerial photography. Control assumed 34 control points (28 new).
· Rice County, MN Airborne GPS. Subcontractor to Martinez Corp. In support of a county-wide aerial photography and mapping project, ASE performed aerial control using Airborne GPS techniques. Rice County is 511 square miles just south of Minneapolis-St. Paul. Twenty-five horizontal and vertical control check points were targeted for the entire photo mission. Two base stations were also established from which the ABGPS would be done. The photography was completed in four photo missions over two days. The GPS receiver in the aircraft and base stations on the ground allowed us to establish accurate 3D coordinates for every photo center on the project. Analytical aerial triangulation was done using photo centers and checking into the 25 check points. Accuracies exceeded those required for the 2-foot contour mapping proposed for the entire county.
Topographic and Engineering Pre-Design Surveys
ASE has a depth of experience in performing and drafting topographic surveys and mapping for major civil engineering improvements that cover vast project areas. For our topographic survey contributions, we were named with the team that won the 2009 ACEC Eminent Conceptor Award for the design of the recent improvements to the Dan Ryan Expressway in Chicago. Our work on the Prairie Parkway required us to perform detailed topographic surveys on vast areas (36-mile corridor). Our topographic mapping work on the new I-57/I-294 interchange involved over 10 miles of roadways. We performed a topographic survey of the underground utilities in a 7.4 mile corridor that covered both Illinois and Iowa in our work on the new I-74 bridge over the Mississippi. We have performed topographic surveys on airfields, in buildings, elevated train platforms and under the ground in subway tunnels, as well as more conventional topographic surveys. Our topographic surveys have been used in engineering designs, lawsuits, criminal cases and environmental remediation studies.