它是如何工作的？是什么使它与众不同？

The GS18 T allows to measure and stake out points faster and more conveniently than ever before. With the GS18 T, it is not necessary to level the pole vertically while doing a measurement or while setting out. You can literally forget the bubble (#ForgetTheBubble). Following aLeica Geosystems GNSS业务总监Bernhard Richter的问答关于新产品，以下对Leica Geosystems应用程序工程师Paul Dainty的采访为我们提供了有关如何使用新Leica GS18 T及其工作原理的更深入的见解。

What makes the GS18 T different? How does it work?

TheLeica GS18 tis different from any other product in the market because it does not rely on a magnetometer to correct the pole tilt for each measurement. A magnetometer is affected by metallic objects, like vehicles, iron fences and beams or even reinforced concrete, all of which are often found on construction sites. In order to provide accurate and reliable tilt values, Leica Geosystems developed an application-specific, powerful and lightweight inertial micro unit (IMU), which is built into the GNSS antenna. The real -time tilt compensation combines GNSS data with the IMU’s tilt and direction values. Different to magnetometer-based GNSS antennas, the GS18 T’s tilt compensation does not need to be calibrated and is immune to metallic object interference.

What about the measurement performance in difficult conditions, such as urban canyons or woods with heavy canopy?

Like theLeica Viva GS16，Leica GS18 T是具有高级性能的自学习的GNSS智能天线。使用RTKPLU的这种自适应测量引擎通过自动选择最佳信号组合，在建筑工地上提供了最佳位置的测量工程师。此外，GS18T为未来做好了充分的准备。凭借其555个频道，它能够跟踪来自全球所有主要GNSS系统的所有信号，例如Glonass，Galileo，Beidou或QZSS（更多详细信息，请参见更多详细信息GS18 T datasheet).

通过倾斜补偿进行测量的准确性如何？

The accuracy depends on many factors. There is the accuracy of the GNSS position. If we look at the specified RTK solution, it is the same as with the GS16 – typically 8 mm + 1 ppm (single baseline length) Hz and 15 mm + 1 ppm (single baseline length) V. The accuracy of the tilt measurement is divided between the tilt accuracy and the direction of tilt accuracy. The tilt accuracy will typically be better than 0°12'00" and the direction of tilt accuracy typically better than 1°00'00". This means over a 1.8 metre pole length, the overall tilt accuracy is typically better than 20 mm at the pole tip with a tilt angle of 30°. This accuracy is comparable and most of the time better than using a conventional GNSS pole with a 20’ level bubble to make the pole vertical.

If the pole is tilted more than 30°, the accuracy of the tilted measurement reduces for two reasons:

1. Tilt accuracy declines as the tilt is increased and the direction of tilt accuracy has higher impact
2. With increasing the tilt angle, the antenna starts to lose track of some satellites, therefore reducing the GNSS position quality.

In any case, the position quality indicator inLeica Captivateshows the combined GNSS position quality and tilt quality, therefore representing the true pole tip accuracy.

极点尖端的精度为0.0175米，在现场屏幕上以Leica Captivate v3.0显示。

Does staking out also work with a tilted pole?

Yes, the tilt compensation can be used in any Captivate app where you can measure, meaning staking out is also much quicker and much more convenient than ever before. When setting out with conventional GNSS equipment, several different steps have to be done at the same time:

• Watching and interpreting the instructions on the screen
• 定向，根据说明移动杆子
• Holding the pole vertical.

Holding the pole vertical, though, is no longer needed. With the GS18 T and the newCaptivate v3.0, setting out is hugely simplified and a completely new experience. Utilising the tilted pole information and sensor heading, the intuitive 3D stake instructions now make it much easier to navigate to a stake point.

Staking out drastically simplified: With the powerful and intuitive 3D viewer, navigating to the point is easier.

What does Leica Geosystems mean with "Measure difficult to reach points that could not been measured before"?

使用常规的GNSS RTK漫游器，诸如障碍物之下的拐角，墙壁，围栏，轻柱或诸如汽车之类的点之类的点之类的点不能直接用垂直杆直接测量。例如，要测量建筑物的角落，您必须测量附近的一个点，并使用替代方法（例如总站）应用偏移或对其进行衡量 - 这两个选项都需要时间来降低生产力。使用GS18 T，可以直接测量建筑物角，因为可以将杆倾斜并轻松快速地放置到角落。对于所有其他难以到达对象的东西也是如此，这意味着GS18 t使测量比以往任何时候都更容易，更快。

For a better understanding, I would recommend to watch the GS18 T how-to-video:

Isn’t the accuracy going to be affected, measuring next to buildings?

That is a very good question and one that people have been asking. When measuring next to buildings, the amount of multipath is likely to increase and a part of the view to the sky will be obstructed by the buildings, reducing the number of visible satellites. This makes for challenging GNSS conditions. The GS18 T with RTKplus technology is self-learning, meaning the sensor will automatically use the best signals and widely mitigate the multipath signals to compute its position. As long as the sensor can track enough satellites, an RTK position will be computed and the GNSS position quality will be displayed. So, whilst the accuracy is not likely to be quite as good as when measuring with an open view of the sky, the displayed GNSS position quality can be trusted so that you always know what accuracy your measured point will have.

在哪里可以尝试新的Leica GS18 T？

轻松，只需联系您local Leica Geosystems distributorand ask for a hands-on demo.

Paul Dainty
Application Engineer at Leica Geosystems