Introduction

This article explains how to use Skylark, Swift Navigation's cloud-based GNSS corrections, with Quectel LC29H-BA or LC29H-DA (no IMU) receivers, to improve computed position accuracy. 


The LC29H is compatible with the following Skylark variants:

Skylark Nx RTK

Skylark Cx

Skylark Dx


Preparation and Tips

To use Skylark corrections with LC29H, the following are required:

  1. Quectel LC29H (BA or DA) with firmware version LC29HBANR11A04S (Check Appendix A to check Firmware version and Appendix B to update Firmware version)

  2. L1/L5 or L1/L2/L5 GNSS antenna in open sky location (refer to GNSS Antenna Placement Guidelines)

  3. Windows, macOS, or Linux computer with Internet access connected to LC29H over serial port

  4. QGNSS V2.1 software available for download on Quectel's Website

  5. Skylark account (if you do not have an account, go to Skylark Sign up)

The procedure outlined below has been tested using LC29H-DA with firmware LC29HBANR11A04S and QGNSS2 V2.1


Receiver Connections

The Skylark corrections are distributed over the Internet using NTRIP protocol. Quectel's QGNSS2 tool features a built-in NTRIP client that operates over an Internet connection (preferably via Ethernet). A reliable Internet connection is required for good navigation performance.


The receiver must be connected to an L1/L5 or triple-band GNSS Antenna. A USB cable is used to connect the receiver to the Control Computer.


Connection Diagram

Connection Setup Example


(1) L1/L5 Antenna on ground plane with Open Sky view

(2) LC29H-DA Evaluation Kit connected to Antenna and Computer

(3) Internet Access using Cell Modem


(4) Windows computer with QGNSS2 software


Setting up Quectel LC29H

  1. Connect the receiver to the computer and note the COM port. Ensure there is internet access.

  2. Start the QGNSS2 software. On the toolbar, click the gear icon, 'Set Device Information'. 
    1. Select the correct COM port
    2. Select the receiver model as LC29H(BA) or LC29H(DA) from the drop down
    3. Set the baud rate as 115200
    4. Click OK

  3. Click on the 'Connect or Disconnect' Icon.
  4. There should be at least 10 satellites in view, strong GNSS signals should reach a level of around 45 dB-Hz, and the receiver should have a valid DGNSS Quality Indicator.



  5. Check the if the firmware version is LC29HBANR11A04S or newer (Appendix A) otherwise, perform firmware update (Appendix B)


Using Skylark Corrections

  1. On the toolbar, go to Tools -> NTRIP -> NTRIP Client


  2. In the NTRIP Client window, under the Client tab, enter one of the following URLs based on your region. Please note that in the URL, l1l5 is lower case L1L5. 
    RegionURL
    Europeeu.l1l5.skylark.swiftnav.com
    North Americana.l1l5.skylark.swiftnav.com
    Asia / Pacificap.l1l5.skylark.swiftnav.com


  3. Enter the Port as 2101 and your Skylark Account credentials

  4. Click 'Update NTRIP source table' button to get the mount points populated.

  5. From the NTRIP mount point drop-down menu, select one:

    DX-MSM1
    		DGNSS corrections sub-meter accuracy
    MSM5Skylark Cx wide-lane corrections ITRF2020 reference frame
    NXRTK-MSM5RTK MSM5 corrections ITRF2020 reference frame


  6. Toggle the 'Connect To Host' button to receive corrections.


  7. Refer to NTRIP Client Configuration for Skylark Corrections for a full list of available mountpoints (corrections data streams), including regional reference frames (datums).

Verifying Use of Corrections


To verify that the receiver is using corrections, check the Data View window and look at the Quality Indicator field. You should see Fixed RTK if you are using NXRTK-MSM5 mount point.



Appendix A - Checking Firmware Version

To check the Firmware Version on the receiver,

  1. On the toolbar, go to Tools -> Command Console

  2. Enter the command $PQTMVERNO

  3. Click 'Checksum' then click Send

  4. Check the Text Window for the response. 

Appendix B - Firmware Update


To update the firmware to the latest version,

  1. On the Toolbar, go to Tools -> Firmware Download

  2. In the Firmware Download window, click Browse and select the latest firmware.bin file.

  3. Click Start

  4. Press Reset Button to complete the Download.

  5. Power cycle the receiver and Firmware download is complete.

References

Skylark Sign up

Quectel DownloadZone 

Quectel LG69T Series


Related Articles

Skylark Nx RTK Specification

NTRIP Client Configuration for Skylark Corrections

Receiver Configuration for Skylark Nx RTK Operation