As-built plans are prepared and delivered by the contractor at the completion of the job. As built plans confirm the project as it has been actually built, showing any changes that were made from the planned and approved plans. SIEA checks the as-built plans to verify and assess their reliability. To accomplish this, SIEA personnel survey and record the actual position of the completed work to compare actual location and the submitted as-built plans. In the process, SIEA produces an accurate reference map for future maintenance and excavation accident prevention.
To start the verification, the as-built plans are downloaded into the EdiPocket software residing on the ProMark 500 rover’s field terminal. The “Measure” menu has a function called “Accuracy Verification” that enables the operator to survey and record the position of the buried line at verification points as the operator follows the covered trench. According to Bruno Forget, SIEA GIS Department manager, most of the current checking is done on newly laid fibre-optic cables. A typical fibre-optic trench, filled in just after cable laying, is about 10 cm wide, which is more than adequate for accuracy verification. The positions are saved in a Shapefile then transferred to an Excel file, which makes the verification calculation and gives the result as-built plan “accepted” or “rejected.”
SIEA uses the Ashtech ProMark 500 receiver, in L1/L2 GPS mode receiving real-time corrections from TERIA, the French GNSS reference station network, and a MobileMapper® CX field terminal. The reliability and ease-of-use of the ProMark 500 rover makes it possible for virtually any operators to perform verification surveys with centimetre-level accuracy in real-time.
Bruno Forget adds that the ProMark 500 receiver with the software EdiPocket not only saves time for SIEA verification crews, but also increases the reliability and consistency of the entire geographic information system for SIEA.
Editop® and EdiPocket® are GIS software products developed by SIRAP which distributes Ashtech products in France. www.sirap.fr
Syndicat Intercommunal d'énergie et de e-communication de l'Ain. www.siea.fr/
About the Ashtech Brand
Recognized as an industry leading brand, Ashtech has been developing GNSS technology for more than 25 years. Ashtech is the creator of BLADE technology, which is a unique method for using multiple GNSS constellations for high-accuracy positioning. Ashtech also introduced the MobileMapper series of products for GIS and mapping, as well as the ProFlex™ 500 and ProMark series, including the ProMark 500, ProMark 200 and ProMark 100, a well-recognized GNSS land survey product line currently on the market.
Following the recent acquisition of Ashtech by Trimble, the Ashtech teams, GNSS solutions portfolio and distribution networks are now part of the Spectra Precision Business.
The Ashtech brand has a worldwide presence and is located in Carquefou, France, with offices in Beijing, China, and Singapore, as well as affiliates in Santa Clara, Calif. and Moscow.
About the Spectra Precision Brand
Spectra Precision has long been an established brand, known for delivering quality products to the construction market. Focusing on the specific needs of the conventional surveying market, the Spectra Precision brand offers a complete product portfolio including Global Navigation Satellite Systems (GNSS), Global Positioning Systems (GPS), optical total stations, data collection hardware, field and office software, as well as a wide range of construction tools.
Spectra Precision surveying equipment is an economical choice that utilizes technologies for optimal efficiency. With convenience and reliability as the foundation of the Spectra Precision brand, it is an ideal choice for value. The Spectra Precision brand is backed with the strong technical support that users have come to expect from a quality name in surveying and construction.
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