From the sky to the ground

Since the late 1990s, the heavy construction industry has increasingly benefitted from GPS technology to achieve highly accurate grade information to complete earth-moving jobs quickly and precisely.

Without a correction of the satellite signals from a reference station with a known position, a machine control solution’s GPS system would have an accuracy only higher than a couple of metres similar to an in-car navigation system. This is not accurate enough for the construction industry that needs positioning precision down to a couple of centimetres.

The machine control solutions therefore need to receive corrected signals using a technique called Real Time Kinematics (RTK) from either a single RTK base station or an RTK network, which is a network of permanent GPS and/or GNSS receivers whose combined data is used to correct transmissions errors from the satellites.

HxGN SmartNet is a worldwide RTK network service based on Leica Geosystems’ GNSS technology. With easy access to precise correction data, users experience the best availability, reliability and traceability using internationally recognised standards, together with flexible and affordable subscription options. Many professionals benefit from HxGN SmartNet to efficiently complete their daily tasks, such as:

• machine control
• surveying
• engineering
• construction
• agriculture
• utility surveys
• archaeology
• monitoring
• and many more.

Smartnet in Denmark

With a total of 57 reference stations, controlled and approved by the Danish Geodata Agency, HxGN SmartNet has the most extensive RTK network and ensures the best coverage across the whole country. The 3D machine control solutions offered by Leica Geosystems Machine Control Division use a correction signal from a reference station or reference station network once every second.

Customers subscribed to HxGN SmartNet receive a SIM card for the earth moving machine's GNSS receiver that connects automatically via the telephone network to the closest reference stations. This allows the machine operator to receive centimetre accurate coordinates from the satellites to his in-cabin panel.

"I depend 100 per cent on SmartNet in my daily work. I receive the project drawings and use the Rover CG60 from Leica Geosystems to mark out roads, wells, cables and so forth. I see instantly if there is something wrong, either with the satellite coverage or with the SmartNet signal, which, by the way, happens very rarely," said Jakob Lind, surveyor at Søren Kristiansen A/S.

A precise positioning network you can trust

The automatic and precise positioning service integrated into machine control solutions only requires a mobile data connection and an acceptable internet connection. This 24/7 GNSS Network RTK and correction service, built on the world's largest reference network, goes unnoticed by its users while it quickly determines precise positions.

"I don't really notice the correction service because it normally works automatically and very well. If I temporarily loose internet connection, I receive a warning on the panel inside my machine," said Thomas Petersen from Fuglsanggard A/S.

This service continuously provides a highly-available infrastructure and even offers all customers a free text message service that reports if there is a problem with HxGN SmartNet and provides information about atmospheric errors. Built to provide high-precision and high-availability, signals affected by solar storms are restored in a couple of minutes and users can follow the information about solar flares and ionospheric errors on the website.

"Signals from the satellites can be affected by trees or tall buildings, and even the time of the day can have an effect on the satellite coverage. The 3D machine control solution gives users a warning on the panel if there is connection to less than the required four satellites or if the RTK signals are too slow," explains Christian Hansen, responsible for the HxGN SmartNet solution in Denmark. "In places with intensive data traffic, for example in the vicinity of large educational institutions, the correction signal can be delayed. If the caused inaccuracy is higher than 5 centimetres due to slow signals, the system will automatically shut down."

With several years' of experience as a machine operator Rune Lodall, sales consultant for Leica Geosystems Denmark recalled, "10 years ago the majority of construction companies used base stations on their job site, but today HxGN SmartNet offers such precise data that it is used for most projects, even for grading jobs that require maximum accuracy."