|The role of the global positioning system (GPS) in terms of infrastructure is an integral and wide ranging role of critical importance today and one that is expanding.
Infrastructure can include roads, rail, utilities, buildings, bridges and other types of structures which are located on the earth’s surface and below it. GPS is used to locate these structures and their position relative to the earth and is often referred to as geo-referencing. Latitude and longitude are the most commonly known values for locating a (x,y) position. However, GPS are capable of providing elevation as well (x,y,z) and therefore hold the promise of locating objects in 3D space. This opens the door to 3D modelling as well.
The measurement of land or cadastral surveying uses GPS. There are numerous methods for applying GPS to achieve highly accurate and useful positioning information. The collected data is later, and usually, entered into a CAD based civil engineering software package allowing infrastructure design and planning to take place. Thus, a connection between the field data collector, usually surveyor, and a design / planning professional takes place, an inter-dependent relationship occurring between the two.
Not all GPS are the same. Mass market or consumer grade GPS are different than professional and surveying grade GPS equipment. One is likely to find their location within 10 m using these devices. Infrastructure involves the use of professional grade GPS hardware, usually providing sub-meter and centimeter accuracies. Levels of accuracy and the means employed to achieve that accuracy are key differences between the two, in addition to other considerations.
Professional grade GPS often include considerations for advanced software processing of the data and often include wireless support, ability to fix in difficult locations, time to fix and other features. The key point here is that infrastructure applications will depend on professional equipment, for obvious reasons. Total Stations have also expanded and developed to include GPS. This means these instruments can be tied into control networks quickly and easily using GPS, as well.
The connection of GPS to support of surveying tasks is important to understand. It provides the means for infrastructure to be planned and designed, built and operated. This means GIS, CAD and supporting software systems, each of which are used during these processes, will often rely upon survey data obtained through the use of GPS.
You will find Virtual GPS Networks (Virtual Reference Systems or VRS) in France, Serbia, Poland, Ireland, Canada, UK and Australia and many other places. These networks provide the technologies which enable professional grade GPS equipment to perform highly accurate measurements across wide areas in a consistent manner, enabling the advanced features of professional GPS to perform. VRS enable infrastructure like pipelines, river systems, roads and other widely spaced features to be surveyed and coupled into one useable network, economically, quickly and with high quality results across many users and projects. This is an important point, since, most countries approach infrastructure with a view to regional or national geodetic survey – linking all forms of infrastructure together.
Machinery automation is a large area that is benefitting from the use and application of GPS. Graders, for example, may have their blades operated through the application of GPS. You may not think 5 cm. of asphalt or gravel on a road is a big deal, but through more precise grading of long stretches of road, significant quantities of money can be saved. Last spring at the Bauma show in Munich, I saw a soil packer operating with GPS and no driver, it was robotic!
The applications for building and automating infrastructure that employ GPS not only saves money, but improves quality. The link of survey collected data to road planning and design, is one example of ‘integrated’ or ‘connecting processes’ together. This is a high level of integration, but is now growing due to the attractiveness of enabling entire organisations and their workflows together with processes into a framework where one data set is distributed and re-used, depending upon individual process needs.
But GPS for infrastructure does not stop here. Infrastructure needs to be operated and maintained. For that reason, monitoring and continuous measurement or observation may be necessary. Bridges needed to be inspected, building shift or deflection needs to be determined and hydro installations need monitoring etc. Often aerial resources are used to obtain this information. Inertial navigation systems (INS) employ GPS to enable airplanes to fly straight and on-target (pitch-roll-yaw). This means any camera or measuring device on board, is acquiring data uniformly with respect to the ground. Thus, a connection can be made between remote sensing and GPS for infrastructure.
Europeans have been deep in discussions about GALILEO GPS of late, perhaps a more important point is the relevance and understanding of how the European Union is positioning GPS respective of transport, energy and security.
While we may be tempted to say GPS is connected to a local project, there is little doubt that it is enabling the connection of people to landbase and the associated infrastructures of living. Spatial Data Infrastructure (SDI) are part of the wider system connecting to GPS enabled environments.
I would suggest that GPS has allowed us to see the world as a series of connected systems and processes, collectively measured and integrated at higher and higher levels. For this reason, GPS enables dynamic and exciting infrastructure projects to be designed, built, visualised, operated and maintained around the world.
The coupling of CAD / GIS / remote sensing to GPS is enabling solutions of high functionality and usefulness. The technology enables us to build a sustainable world.
||GPS receivers are critical tools for infrastructure creation and maintenance. The dynamics of any construction site benefits greatly from precision tools that constantly update progress related to the plan.
The days of survey stakes are nearing their end. Instead, project managers will be able to monitor and manage site progress thanks to dynamic Web-based visualization systems with precision GPS receivers as the primary sensor.
Construction Site Management
GPS and surveying vendors have long understood the need for greater asset management on a construction site, and software tools and systems have begun to come online to greatly streamline construction operations. The use of GPS to track assets and personnel on a construction site, tied to a time line of tasks that need to be completed, can greatly increase efficiencies and provide significant cost savings.
The concept of a construction asset management solution for a connected construction site has come online this year. Trimble’s Construction Manager software is designed to combine into one view the locations of mobile assets (trucks, heavy equipment, etc.), portable assets (generators, compressors, etc.) and personnel. The system is marketed for its ability to help allocate resources effectively, reduce equipment rental, reduce maintenance and fuel cost, improve safety, improve worker efficiency and reduce overtime. All of these items has a dollar sign attached, and the net affect on bottom line promises significant ROI.
Topcon recently unveiled a similar job site management solution with their SiteLINK software. Topcon has designed their wireless network of in-cab devices to act as a mesh network that act as repeater stations and increase data transmission capabilities between each other and the office.
Another revolution on the construction site is the use of precision GPS on machinery for 3D grading and excavation. These systems use GS, laser and total stations to position the blade of earth movers in real time. Rather than requiring surveyors to stake and re-stake a construction site, these systems allow the machine operator to maintain consistent grade by keeping a close eye on the design plan within the cab.
Bringing the design into the cab gives the operator greater control and has been said to increase job satisfaction. There’s greater work site safety and efficiency because grade stakers and checkers aren’t required on the job site. The resulting grading is done with greater accuracy, more quickly with lower operating costs and reduced material cost.
Survey-grade GPS can be used to measure the movement of a structure due to wind deflection, traffic loading and temperature changes in real time. The active GPS monitoring of a structure provides a accurate record of movement in 3D space that when correlated with time provides monitoring information that is hard to match with any other combination of sensors.
I had the opportunity to see such a system up close on the Tsing-ma Bridge in Hong Kong in 2001 as a guest of Leica. This bridge is the longest span suspension bridge in the world and carries both road and rail traffic to the new Hong Kong airport.
The heavy loads on the span due to traffic is constantly monitored and managed to reduce stress on this span and decrease the need for maintenance. The bridge is also in an area that is susceptible to typhoon winds. The monitoring of the span during extreme weather events is critical for safety and provides a helpful performance record that can improve bridge design.
That trip gave me a great appreciation for engineering-grade GPS with millimeter level accuracy. Similar equipment has been installed to monitor dams, maintain slope stability, monitor skyscraper wind displacement, etc. Each of these monitoring systems is driven by the need for long-term maintenance planning and real-time safety.
GPS has an enormous role to play for increasing the efficiency of construction management, the accuracy of what’s built, as well as the safety and maintenance of our world’s infrastructure. I’m excited about the next wave of integrated spatial products that will combine multidisciplinary knowledge, taking the best of each area of expertise for the betterment of all.