Technology

What is Z-Blade?

Ashtech, a Trimble company, invests heavily in the development of cutting-edge technology to further strengthen its position as a leading designer and developer of precision positioning technology. Recent developments have produced greater product integration and progressive augmentations to GPS/GNSS. These advances are apparent in the latest line of OEM products including the new Ashtech Z-Blade™ Technology.

Z-BLADE: the Ultimate GNSS Technology
Z-Blade is Ashtech’s proprietary, state-of-art Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) and Differential GNSS (DGNSS) engine that is the core GNSS data processing technology in Ashtech’s OEM products. Z-Blade contains patented techniques for the optimal combination of different GNSS signals or with just a single satellite group.

Most existing RTK engines were created as GPS (L1 only or L1&L2) engines. They were not initially designed to properly support other GNSS signals for each RTK-specific application. Adding other GNSS signals and specific functions to existing GPS-only source code may lead to non-optimal performance. Z-Blade was initially designed as a complete GNSS multiband engine (GPS+GLONASS+SBAS+Galileo or other GNSS signals, L1&L2 or other bands) to support a very wide range of RTK applications from classic RTK/DGNSS rover against static Base/Network up to exotic applications like RTK against a moving base or attitude determination.

A growing number of available satellites are providing significantly improved GNSS receiver performance in difficult satellite tracking conditions. However, the majority of GPS solutions rely on GPS-centric technology. There must be a GPS satellite in the mix to provide RTK results. With Z-Blade, a GPS satellite does not have to be visible. Z-Blade can use a mix of satellites or only satellites in a single constellation. The result is more reliable measurement processing and usage than with competing board or GNSS receiver offerings.

The Key Distinguishing Features of the Z-Blade Engine Include:

High-end Z-BLADE performance is achieved not only by optimal processing of GNSS raw data (Ashtech and third party), but also with the proper usage of other available information (e.g. atmospheric parameters at base and rover).

How Z-Blade Benefits L1 Solutions:
The L1 GPS RTK solution from Ashtech allows SBAS measurements to be used in the RTK process, thus making it a true affordable GNSS technology. SBAS gives extra GPS-like measurements that improve satellite geometry and allow centimeter- level accuracy to be achieved faster than with the GPS only.

Z-Blade technology enables Ashtech L1 GPS RTK solutions to outperform other single-frequency RTK receivers. Z-Blade’s unique GPS+SBAS RTK algorithm ensures quick initialization with single frequency receivers and takes full advantage of the maximum satellite coverage from the dual constellation.

Z-BLADE Benefits for Float RTK operations:
The goal of Float RTK is to insure position convergence to decimeter level. Float RTK never tries to fix the ambiguity, so there is no such thing as reliability. Usually, L1 RTK is float-ambiguity RTK, because single-band data (even with open sky and short baseline) cannot guarantee reliable and fast ambiguity fixing. The main disadvantage of Float RTK is the quite slow position convergence to decimeter level.
Thanks to Z-Blade, Ashtech has created a so called Flying RTK solution that enables improving the Float RTK performance of Ashtech receivers. Z-BLADE improves standard Float RTK performance as it dramatically reduces the time of convergence, it enables Ashtech solution to reach the decimeter accuracy level quicker at a lower cost than competing systems.

Additionally, Z-Blade enables Ashtech GNSS boards and receivers to work with any other manufacturer's base or reference stations by automatically measuring and removing the biases that are inherent with the Frequency Dependent Multiple Access (FDMA) technique used in GLONASS. The Ashtech Professional boards, sensors or complete receiver solutions with Z-Blade technology inside get the full benefit of any available GLONASS corrections