Skip to main content

Posts

Showing posts from July, 2016

How to connect Precis-BX305 to base and reference station?

Precis-BX305 L1/L2 GNSS RTK Boards can connect to reference via radio or Internet. For radio case, you need external radio module for data link. For Internet case, you need an external Bluetooth module to connect to your phone. A quick start video describes how to connect and configure is coming soon. If you have further questions, feel free to contact us to   info@tersus-gnss.com   or visit our official website   www.tersus-gnss.com Tersus Available on Facebook, Twitter, LinkedIn We have created our Fan Page to keep you updated through the most used social network in the world. Come to "Like" or "Follow" us. Facebook:   https://www.facebook.com/tersusgnss Twitter:   https://twitter.com/wwen0920 LinkedIn:   https://www.linkedin.com/company/tersus-gnss

Which RTCM version does Precis-BX305 support (in case to use network RTK)?

Precis-BX305 L1/L2 GNSS RTK Boards support RTCM 2.X and 3.2. The details of supported RTCM messaged can be found in the Precis-BX305 User Guide. The RTCM 2.X only supports GPS and GLONASS. If you want to use network RTK, you may need a serial modem to connect the board to Internet as the board does not has built-in network access feature. If you have further questions, feel free to contact us to   info@tersus-gnss.com   or visit our official website   www.tersus-gnss.com Tersus Available on Facebook, Twitter, LinkedIn We have created our Fan Page to keep you updated through the most used social network in the world. Come to "Like" or "Follow" us. Facebook:   https://www.facebook.com/tersusgnss Twitter:   https://twitter.com/wwen0920 LinkedIn:   https://www.linkedin.com/company/tersus-gnss

Can Precis GNSS RTK Boards connect to Pixhawk/Autopilots? How?

Precis-BX305 GPS RTK board can be integrated with autopilots. In this article, the connecting to Pixhawk flight control is used as an example. A cable is used to connect the COM1 port of Precis-BX305 board and the GPS port of the Pixhawk (see Figure 1). It is noticed that the GPS port need a 6pin PicoBlade connector while the COM1 port is a 5pin PicoBlade connector. The pin definition of the Pixhawk GPS port is listed in Table 1. With regarding to the power consumption, we recommend using external power sources. Please also pay attention to the baud rate setting of Pixhawk as the default baud rate of Precis-BX305 board is 115200. The Pixhawk can only recognize the NMEA sentence with GP NMEA talker. Incorrect NMEA talker configuration may cause connection failure. Table 1: Pin definition of Pixhawk GPS port (from left to right) Figure 1: Demonstration of Integration with Pixhawk Autopilot Then you need to mount the GNSS antenna and tether the board on your vehicle. ...

What is GNSS/GPS RTK and how does it work?

GNSS is short for Global Navigation Satellite Systems and RTK is for Real-Time Kinematic. The positioning modes we described in the article “What is the principle of GNSS positioning?” illustrate the difference between standard point positioning (SPP) and precise point positioning (PPP) as well as Differential Global Positioning System (DGPS) and RTK. For applications that require higher accuracies, RTK is a technique that uses carrier-based ranging and provides ranges that are hundreds of times more precise than those available through point-based positioning. GNSS RTK is a precise relative positioning technique, which achieves centimeter positioning accuracy. RTK positioning requires two set of Tersus RTK boards at minimum, which are used as the base station and the rover station respectively. Normally, the base station is set up on a fixed known point and it consistently transmits differential corrections to the rover station. The rover station receives differential correct...

Precis-BX305 Quick Start Guide for GNSS/GPS RTK Boards/Receivers Released

Welcome to the Precis-BX305 Quick Start Guide. Here you will find instructions for how to use the Precis-BX305 RTK board in some simple steps with illustration. Of course, more details of its application could be found in Precis-BX305 User Guide. We are also glad to share with you that Tersus GNSS Center V1.0, which is the official configuration software for all Precis RTK boards is available now. It is a PC tool to help users configure the RTK board and visualize running status. The Quick Start Guide of this software is on the way. Stay tuned. To download the Precis-BX305 Quick Start Guide and Tersus GNSS Center, please visit www.tersus-gnss.com/pages/document-software or contact us at info@tersus-gnss.com

What can I do if Precis GPS RTK board (BX305) cannot position?

The problem can be diagnosed by following procedure. -Check whether indicator lights are blinking. If not, then check power supply system, e.g. whether the wire is well connected. -Check whether Precis output NMEA data. If not, configure output of Precis with configuration tools. -Check NMEA data, if NMEA does not contains valid data, e.g. $GPGGA,051502.00,,,,,0,00,99.99,,,,,,*7B, then check whether antenna is connected to Precis. -Check NMEA sentence $GPGGA, if the GPS status section in $GPGGA sentence is 1, and then it means Tersus/Precis is working in point position mode, then check the status of RTCM data stream. If GPS status section is 4 or 5, it means Tersus/Precis is working in relative positioning mode and everything goes well. If the GPS status is 4, then you get centimeter level RTK fixed solution. If the GPS status is 5 then you get sub-meter level RTK float solution. Remark: the seventh section in $GPGGA sentence in the GPS status, which is after ‘E’ o...

How do Precis GPS RTK boards provide synchronization with camera shutter?

It depends on which solution (Precis GPS RTK boards) you are using. For Precis-BX305, it supports PPS output, which is useful in shuttle synchronization. For Precis-BX316, it can work with event marker. This version will be released in Q4 this year. If you have further questions, feel free to contact us to  sales@tersus-gnss.com  or visit our official website  www.tersus-gnss.com Tersus Available on Facebook, Twitter, LinkedIn We have created our Fan Page to keep you updated through the most used social network in the world. Come to "Like" or "Follow" us. Facebook:  https://www.facebook.com/tersusgnss Twitter:  https://twitter.com/wwen0920 LinkedIn:  https://www.linkedin.com/company/tersus-gnss

Can Precis GPS RTK boards log raw observation data for post process?

All Precis GPS RTK boards (BX305 and BX316) support raw observation data logging. They boards support external data logger. The logged binary observation data can be converted in to Rinex 3.2 with Tersus Rinex Converter. If you have further questions, feel free to contact us to  sales@tersus-gnss.com  or visit our official website  www.tersus-gnss.com Tersus Available on Facebook, Twitter, LinkedIn We have created our Fan Page to keep you updated through the most used social network in the world. Come to "Like" or "Follow" us. Facebook:  https://www.facebook.com/tersusgnss Twitter:  https://twitter.com/wwen0920 LinkedIn:  https://www.linkedin.com/company/tersus-gnss

What is the principle of GNSS positioning?

Satellite based positioning relies on measuring distance between satellite and receivers. With known satellite position and measured distance between satellite and receiver, the coordinate of receiver can be calculated. However, the electromagnetic signals emitted by satellites are perturbed by atmosphere and clock errors, which degrade GNSS positioning accuracy. There are two types of positioning mode, one is point position and the other is relative position (see Fig 1). Point positioning includes standard point positioning (SPP) and precise point positioning (PPP). Their major difference is whether use the carrier phase observation. Relative positioning also includes two types: DGPS and RTK. Their difference is the latter one uses carrier phase observation as well. Relative positioning cancels most error sources in distance measurement by making difference between two receivers, so it is more simple and reliable, but it only measures relative position. In practice, the coordinate of...