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FAQs
Q
Will the Tersus PPK solution work with my autopilot/flight controller?
A

Yes! Tersus PPK solution is platform independent, which does not just mean that it can go from your fixed wing UAV to your Multi-rotor but also means that it operates independently of your flight controller. In fact, there is no connection between the Tersus system and your flight controller, unless you are using your flight controller to trigger event mark in Tersus system or use Tersus system for navigation purpose. So whether you are using an APM, Pixhawk, NAZA, WOOKONG, MICROPILOT, Mikrokopter, Microdrone, or any other flight controller, Tersus PPK solution will still work!

Q
How does Oscar realize Real-Time Kinematic Tilt Compensation with IMU? What is the principle?
A

Oscar combines IMU data and GNSS RTK results to real-time calculate the three-dimensional attitude of Oscar, thereby deduce Oscar's tilt angle. 

Q
What is the meaning of 2cm in 'Tilt Compensation Accuracy (within 30° ) ≤2cm'?
A
2cm is the compensation accuracy for tilt measurement, or the degree of accuracy degradation due to tilt measurement. The additional Hz pole tip uncertainty is typically less than 8mm+0.4mm/° tilt down to 30° tilt.
Example A: If the 3D accuracy of RTK survey is 2cm, and tilt angle is 0 degree, thus the total accuracy is better than sqrt(2cm * 2cm + 0.8cm * 0.8cm) = 2.15cm.
Example B: If the 3D accuracy of RTK survey is 2cm, and tilt angle is 30 degrees, thus the total accuracy is better than sqrt(2cm * 2cm + 2cm * 2cm) = 2.85cm.


Q
What kind of differential message protocols do Tersus GNSS OEM boards support?
A

The Tersus GNSS OEM boards support RTCM 2.x/3.x/CMR/CMR+. Other communicated differential messages include correction message, correction data and differential data.

Q
How long does it take for Tersus GNSS OEM boards to get its first fixed solution?
A

In open sky environment, the initialization time for different first fixed solutions is listed as below.

Cold start:

        - Single point positioning <40 seconds

        - RTK positioning<10 seconds

Warm start:

        - Single point positioning <20 seconds

        - RTK positioning<10 seconds

Q
Is there any configuration required for receiving different forms of RTCM?
A

There is no extra configuration necessary for receiving different RTCM messages. The Tersus BX GNSS OEM boards can automatically recognize RTCM2.X or 3.X. There is no significant difference between the versions.

Q
What are the general reasons that a rover can’t get fixed solution?
A

In theory, there are two inputs to a rover, the satellites signals from the antenna and corrections from the base. So if the rover can’t get fixed solution, please check the following:

Does the antenna have good view of sky and is the communications connectivity reliable?

Is the power to the antenna is OK?

Have the RTK corrections from the base been transmitted successfully?

The corrections datalink is OK.

The baud rate and the receive type of the rover’s port are correct.

Q
Why a BX receiver outputs unreadable code?
A

The possible reasons are:

The receiver’s baud rate is not the same as the computer’s port.

The USB adapter driver has not installed correctly.

The GND signal of the adapter is not reliably connected to the GND of the receiver.

Q
What are the possible reasons that a BX receiver can’t communicate with a computer?
A

The driver for the USB adapter is not installed successfully.

The receiver’s baud rate is not the same as the computer's port.

The receiver port’s Tx/Rx type is not correct.

The cable connection is not reliable.

Q
What are the software tools to communicate with the BX receivers?
A

The BX receiver has a serial port, so in theory, any serial tool can be used to communicate with it, for example, Hyper-terminal, UarTerm or SSCOM32. It is recommended that the Tersus GNSS Centre, a graphic serial tool, is used to communicate with BX receivers

Q
What source format does the Tersus RINEX Converter support?
A

The Tersus RINEX Converter supports raw measurement data and RTCM data. This data can be converted to RINEX 2.10 or RINEX 3.02 by using the Tersus RINEX Converter.

Q
Can the Bluetooth module (BT120) be paired with an iPhone?
A

The BT120 Bluetooth module cannot pair with an iPhone. It can only pair with Android smart phones.

Q
What are the possible reasons that the Bluetooth module doesn’t work?
A

The Bluetooth module is not powered correctly. It may be necessary to power cycle the BX receiver.

The Bluetooth in a smartphone can’t be paired successfully with the Bluetooth module. The module can only communicate with an Android system.

The baud rate of the Bluetooth is 115200, so ensure the receiver’s serial port has also been configured to 115200 baud rate.

Q
What's the radio frequency range of the radio module?
A

Tersus offers four kinds of radio modules.

Radio Model

Frequency (MHz)

Power (W)

Transmission Distance
(KM)
915MHz small radio895-935
0.50.3
433MHz small radio403-4700.50.3

915MHz Eagle radio

91513
RS05R radio410-4700.5, 15


Q
Why does the BX306 not output RTCM data after the RTCM output related commands have been keyed in?
A

It may be caused by following reasons:

A fixed coordinate must be defined for the BX receiver before the RTCM output can be sent. Therefore, use the Fix Position command (see Tersus GNSS Command & Log Reference document) to fix the coordinate first.

Check the Interfacemode. If the target serial port is not in right mode, it may not output RTCM properly. Use the Interfacemode command (see Tersus GNSS Log & Command Reference document) to set the serial mode.

Q
Why the mission planner cannot recognize a BX OEM board?
A

It can be caused by following reasons:

Check the power supply. The BX306 board power consumption is about 3W. Note that although a Pixhawk controller can supply power, its output power capability is far less than 3W, in which case the BX306 must be powered by an external power source. A voltage convertor is recommended to convert 12V battery power output 5V for connection to a BX306 board.

Please check the baud rate settings within the Mission Planner. It cannot be recognized if incorrect baud rate is used. By default, the baud rate of BX306 COM1 port is 115200 bps.

Please check the NMEA output. The Mission Planner requires GPS sensors outputs, i.e., NMEA GGA sentence, RMC sentence and VTG sentence, at 5Hz. Missing VTG sentences or low update rates may cause recognition failures.

Check the NMEA talker. Note that the Pixhawk can only recognize the NMEA sentence with GP NMEA talker. Incorrect NMEA talker may cause failure.

Q
What is Tersus GeoPix?
A

Tersus GeoPix integrates the functions of GNSS observation post processing, Event Mark interpolation and Geotagging in EXIF. By clicking one button after input all necessary data, the software provides the result directly as input for image processing software. Tersus GeoPix is a part of Tersus Tool Suite which can be downloaded from Tersus official website.

For details, please visit: https://www.tersus-gnss.com/software

Q
What is Tersus TC50?
A

The Tersus TC50 Controller is a rugged multi-functional data controller with design of 5'' HD touch screen and an alphanumerical keypad. Equipped with powerful Octa-core processor and android operating system, it is perfect to adapt with Tersus survey software. With professional IP68 rating, it is robust and reliable for harsh operating conditions. 

For details, please visit: https://www.tersus-gnss.com/product/tc50-controller

Q
What is Tersus TC40?
A

The Tersus TC40 Controller is a rugged smart phone with design of 8'' IPS screen and 1280*800 resolution. Equipped with Android 8.1 mainstream operating system, 8-core 2.0G processor, it is perfect to adapt with Tersus Survey software and run fast. The 9000mAh large capacity battery is detachable, which can work continuously for 10 hours without pressure. The unique rounded corner design and plastic shell are compatible with appearance and protection. With professional IP67 rating, it is robust and reliable for harsh operating conditions.

Q
What is Tersus TC30?
A

The Tersus TC30 Controller is a rugged controller with the design of 5'' touch screen and full keypad. Flexible interfaces such as Bluetooth, Wi-Fi, 3G/4G and DB9 serial port make it convenient to connect to GNSS receivers and transceive correction data. Equipped with Windows Mobile operating system, it is perfect to adapt with MicroSurvey FieldGenius software and other field application software. With professional IP67-rated protection, it is robust and reliable for harsh environment. 

For details, please visit: https://www.tersus-gnss.com/product/tc30-controller

Q
What is Tersus TC20?
A

The Tersus TC20 Controller is a rugged smart phone with design of 4.3'' touch screen and an alphanumerical keypad. Equipped with powerful processor, it is perfect to adapt with Tersus Survey software. With professional IP68 rating, it is robust and reliable for harsh conditions.

For details, please visit: https://www.tersus-gnss.com/product/tc20-controller

Q
What is Tersus T18M?
A

The T18M is a GNSS controller equipped with an alphanumerical keypad, a 3.7" sunlight readable screen and a powerful processor, which is designed to improve surveyors' productivity.
With a rugged IP54-rated enclosure that can survive 1.2 meter free drops, the T18M is a perfect solution for the harshest operating environments. In addition, the Li-ion, 6500mAh-capacity battery can support prolonged fieldwork.

For details, please visit: https://www.tersus-gnss.com/product/t18m-controller

Q
What is Tersus Nuwa?
A

Nuwa is a survey application software based on Android OS (Operating System), designed by and all rights reserved to Tersus GNSS Inc. Nuwa is simple, easy to use and has a friendly user interface. It is designed to work with David GNSS receiver, Oscar GNSS Receiver and other receivers which support NMEA-0183.

- Supports Bluetooth and USB connection

- Configure Base, Rover and Static Survey

- Graphical Interface with background map (online/import)

- CAD Stakeout, Road Stakeout and Earthwork

- Data Management (import/export multiple formats)

- Various built-in tools

For details, please visit: https://www.tersus-gnss.com/product/nuwa

Q
What are the classes of applications that can be used with Tersus Oscar/David?
A

Generally speaking, there are several main classes of applications that can be used with Tersus David GNSS receivers to attain high-precision positioning details.

- Rover + CORS 

- Base + Rover + Radio

- Base + Rover + Tersus NTRIP Caster

- Raw Measurements Collection

Q
What is Tersus Oscar?
A

Tersus Oscar GNSS receiver is a new generation of tilt compensation GNSS receiver. Empowered by a high precision inertial measurement unit (IMU) on Ultimate version, this kind of calibration-free tilt compensation is immune to magnetic disturbances. Oscar gives a surveyor unprecedented flexibility and efficiency - holding the survey pole upright is no longer necessary. With an internal high-performance multi-constellation and multi-frequency GNSS board, Oscar GNSS Receiver provides high accuracy and stable signal detection.

The built-in high-performance antenna can speed up the time to first fix (TTFF) and improve anti-jamming performance. With a Nano-SIM card inserted in Oscar, it can access Internet, transmit and receive correction data through 4G/WiFi network. The built-in UHF radio module supports long distance communication. The built-in large capacity battery is detachable and can display power level. Two batteries support up to 16 hours of fieldwork in 4G/3G/2G network and Rover radio mode. Oscar can be easily configured with 1.54'' interactive screen on Ultimate and Advanced versions. The rugged housing protects the equipment from harsh environments.

For details, please visit: https://www.tersus-gnss.com/product/oscar_gnss_receiver

Q
What is Tersus BX40C?
A

The Tersus BX40C is a compact GNSS RTK board with full constellation tracking for providing cm-level accuracy for positioning. In-built 8GB memory makes data collection easy. It features compatibility with other GNSS boards in the market via flexible interfaces, smart hardware design, and commonly used log/command formats.

For details, please visit: https://www.tersus-gnss.com/product/bx40c