Technical Appendix
Issues and Solutions
Issues about David GNSS Receiver 1. Bluetooth / USB cannot be connected with David.
Solutions:
(1) Check if other devices have connected to Bluetooth (COMM1-Bluetooth module only supports Android phones);
(2) Check if the Bluetooth model matches the David GNSS receiver, the David-R model matches the BT420R model of Bluetooth module, and the David model matches the BT420A model of Bluetooth module;
(3) Check if the David GNSS receiver is powered on normally. If the receiver's LED is bright but cannot search for the Bluetooth name, please delete the matched Bluetooth in the phone and search again. If you still cannot find the Bluetooth device name, please contact the supplier for assistance;
(4) Reconnect USB and allow USB device to connect when USB cannot be connected;
(5) If the radio base station mode is used, check the power supply. At this time, only the 12V battery can be used for power supply. Do not use 5V power bank for power supply.
2. David GNSS receiver cannot be located.
Solutions:
(1) Check if the GNSS antenna is properly connected;
(2) Check if the GNSS antenna cable and connector are intact or damaged.
(3) Ensure that the GNSS antenna is placed in an open outdoor environment;
(4) Check if David's LED light is in normal startup state.
3. The rover with 2W radio kit cannot obtain a fixed solution.
Solutions:
(1) Check if the radio 'T/R' LED is in the receiving state with blue light. If it is not in the receiving state, press and hold the 'CHAN' and 'PWR' buttons for about 1 second to switch to the receiving state.
(2) Check whether the number of channels and the transmission protocol of the rover are consistent with that of the base radio;
(3) Check whether the baud rate of the serial port of the 2W radio and the base radio is normal. The baud rate of the serial port of the 2W radio and the 30W radio is 38400bps, and the baud rate of the serial port of the 1W radio is 115200bps.
4. The rover network mode cannot obtain a fixed solution.
Solutions:
(1) Check if the network of the rover is normal, and whether the controller (an android device) can connect to the network normally;
(2) Check if the rover's user name and password are correct, pay attention to case sensitivity, and there is no '@' character at the beginning of the rover's password;
(3) Check if the rover's MountPoint is consistent with that of the base. It is recommended to use the default base serial number as MountPoint;
(4) Check if the base has sent corrections data normally.
5. The base radio constantly restarts.
Solutions:
(1) In the base radio mode, only 12V battery can be used for power supply, and 5V power bank cannot be used for power supply;
(2) Check if the battery is low power or insufficient voltage.
6. The local coordinate deviation of the rover is large.
Solutions:
(1) Check if the coordinate system of the project in Nuwa application is configured correctly;
(2) If site calibration or parameter calculation is not performed, the base needs to be configured by manual start, and the known point coordinates of the base configuration should be consistent with the known point of the actual installation;
(3) If site calibration or parameter calculation is performed, check whether the coordinate of the control point is incorrectly entered, whether the coordinate deviation of the control point and the distribution of the control point is uniform, and whether the scale is close to 1 in the parameter calculation result.
7. It prompts that the coordinate deviation is large when configuring base.
Solutions:
(1) If the input is WGS84 coordinates, check whether the input coordinates are the same point, and the coordinate difference cannot be greater than 30m;
(2) If the input is local coordinates, check whether the configured coordinate system is consistent with the coordinates that need to be input.
8. The time for the rover to get a fixed solution is too long.
Solutions:
(1) Check the number of satellites for the rover, the satellite distribution (whether the occlusion is serious), and the satellite signal-to-noise ratio (whether the maximum signal-to-noise ratio is greater than 50);
(2) Check if the antenna connection is loose;
(3) Check whether the correction data of the base is normal, and whether it includes correction data of GPS, GLONASS, and BeiDou systems.
Issues about Oscar / Luka GNSS Receiver 1. The receiver cannot search satellite signals.
Solutions:
(1) Change test environment, restart the receiver in an open space;
(2) Reset the Oscar GNSS module by holding the FN button and pressing the power button five times.
2. The internal radio cannot transmit data
Solutions:
(1) Check whether the receiver can search satellite signals normally;
(2) Check whether the whip antenna is properly installed;
(3) Check whether the radio protocol and channel are configured correctly and are consistent with that of rover.
3. Cannot log in CORS
Solution:
Check whether the 4G SIM card is installed and used normally.
4. Nuwa cannot connect with Oscar / Luka
Solutions:
(1) Check whether the receiver is powered on;
(2) Re-search and pair Bluetooth;
(3) Update Nuwa to the latest version.
5. There is no correction data when the receiver as a rover and using Ntrip network
Solutions:
(1) Check whether IP address, port, user name and password are correct;
(2) Check network connection, try to compare with PDA network and ensure SIM card contacts with card slot properly;
(3) Obtain source table to check receiver network, make sure there is no abnormal of CORS service;
(4) If there is an extra receiver, try logging into the same configurations and make comparisons;
(5) If you still cannot log in, consult your CORS service provider.
6. How to export static observation data?
Solutions:
(1) Connect receiver with a computer through a mini USB cable.
(2) The computer detects the receiver as an external disk.
(3) Open the Record folder, find the trs file and Rinex file in its storage according to recording date.
(4) Copy the static observation data and paste them to the designated folder in your computer.
7. How to calibrate the E-Bubble of receiver?
Solutions:
(1) Firstly, install the receiver on the tribrach of a tripod. Adjust the tribrach to enable the bubble to the center.
(2) Next step, select <Adjust> in the Nuwa under Device Info -> E-Bubble to complete the calibration.
8. How to apply Geoid model file correctly?
Solutions:
(1) Prepare the Geoid file at first and placed in the path of Internal storage\TersusSurvey\Geoid.
(2) Next step, launch Nuwa and go to select Project - Current Project and edit Coordinate System. Find the Height Fitting-Adjust Method and select Geoid.
(3) Last, select the file under Geoid List and apply it.
9. How to configure serial port output NMEA log?
Solutions:
There are two ways to realize the NMEA sentences output which you'd like to.
(1) Nuwa can configure to output NMEA by the NMEA option. It can be specified the Baud Rate, the kind of sentence.
(2) Variable bonus, it can be directly configured on the panel. NMEA can be turned on through Device Info -> Serial.
10. A base receiver is working well, the rover receiver cannot get correction data, how to fix this?
Solutions:
(1) Check whether the radio antenna connects well with receiver. Carefully check whether the interface is tightened.
(2) Check whether the air baud rate, Protocol, Bandwidth, Frequency match right with that of the base receiver.
(3) Switchover the radio frequency to avoid the possible interference from nearby devices.
11. The rover works at a short distance (not normal distance) at the radio mode?
Solutions:
(1) Check whether the rover connects a radio antenna.
(2) Adjust the radio of base at the high power gear.
(3) Check the environment if there exists radio interference along the propagation line.