Instead of purchasing a closed single- or dual-constellation receiver today — only to be forced to replace it when Galileo is operational – surveyors can invest in a triple-constellation GR-3 receiver, and grow its abilities as their needs change, or when Galileo is ready.
The bottom line is that GR-3 owners don’t have to pay for Galileo capabilities at the time of purchase. As their needs change, existing owners of the units will be able to purchase the Galileo option once the new constellation is up and running.
The new G3-powered GR-3 has 72 ‘universal’ channels. It can track up to 36 positioning satellites simultaneously, from any of the available satellite systems.
It can be used as either a base or a rover in a static or real-time kinematic (RTK) configuration. It can also be used as a rover in a GNSS network.
With an initialisation time typically less than five seconds, the GR-3 is very fast; it is also very accurate.
Carrier phase static positioning is 3 mm + 0.5 ppm horizontally and 5 mm + 0.5 ppm vertically. In RTK mode, accuracy is 10 mm + 1 ppm and 15 mm + 1 ppm respectively.
In addition to its triple-constellation tracking, the GR-3 receiver incorporates many other unique features.
These include dual, hot-swappable batteries, giving a battery life of more than 12 hours – the longest in the industry. The lithium-ion batteries ensure a full day’s operation without the need to shut the receiver down to change batteries. They can be changed during operation without loss of signal or position lock.
The two rechargeable battery packs are mounted on the exterior of the unit for easy access. They cover the SIM and SD media card slots, shielding them from the elements.
An extra battery housing is included, which accepts AA batteries for emergency operation. This makes the GR-3 the first RTK receiver on the market to accept off-the-shelf batteries. It means that users can continue to operate the unit, even when they forget to charge the batteries overnight.
It also has an on-board 900 MHz spread-spectrum radio, which provides reliable and interference-free RTK communication, even at a great distance from the base to rover unit.
In addition to the spread-spectrum radio, the unit can be used with an optional RE-S1 radio extension repeater, allowing the radio signal to be re-transmitted. This dramatically expands its coverage to allow a user to cover multiple job sites, or very long linear sites, such as major road construction.
Alternatively, one can use an internal GSM/GPRS SIM card modem for mobile connectivity where this is available.
The cellular communication system is installed through the easily accessible mobile phone card SIM slot. It enables the receiver to connect to a base in a GNSS network, sometimes referred to as a VRS (Virtual Reference Station) network.
Another feature is the use of Bluetooth wireless technology. This gives users completely cable-free operation between field controllers and other compatible devices. Provided the data collector and the radio remain within a few metres of the receiver, no cabling is necessary.
In designing the unit, Topcon engineers have been mindful of the fact that not all surveyors treat their equipment with the respect it deserves. The unit comes with a magnesium I-beam housing for durability.
It is designed to withstand a drop onto concrete from a two metre pole – recognition of the reality that in the field, this equipment is subject to occasional rough treatment.
All these features are designed to enhance ease of use and maximise uptime.
The GR-3 also incorporates a number of other significant features that can make a great deal of difference in the day-to-day operation of GNSS equipment.
The radio antenna is mounted on top of the GNSS receiver, instead of underneath. This provides extra radio range, saving operators the need for a second set-up of the base station in order to reach those last, far-away points with the rover.
The receiver is housed in a square box. It can be leaned up against a wall in order to maintain lock on the satellites. The more traditional round design would roll over and fall down.
A unique snap-mount has replaced the usual 5/8 inch thread. It takes only a second to mount the receiver to the pole.
A user-accessible slot for standard SD memory cards lets users decide how much memory the receiver should have.
Bright LEDs angled downward allow operators to easily check the status of the receiver.
All these ergonomic features are designed to improve productivity. At Topcon, our design philosophy is that a GNSS receiver should to be flexible and easy to use. It should work under all conditions.
We are confident that the GR-3 will be the benchmark of GNSS receivers for many years to come. We are very excited to be able to offer this receiver of the future to Australian and New Zealand surveyors today.
Topcon provides technical support and software version updates for its receivers free of charge throughout a product’s life, so support for the GR-3 is part of the purchase — not something that has to be bought separately.
The GR-3s all-inclusive triple-constellation satellite tracking capabilities means that it is quite possibly the last GNSS receiver a user will ever need.
Neil Other is Topcon Positioning Systems’ sales manager in Australasia. For more information visit www.topcon.com