LC29H L5 Signal Questions

IoT Modules GNSS Module
1

I have some LC29H receivers (DA and BS models) that are connected to separate L1+L5 antennas. The receivers both work fine and receive L1 and L5 signals from GPS, Galileo, BeiDou, and L1 signals from GLONASS, as described in the receiver specifications and product brochure.

Referring only to L5 signals, when I was configuring the receivers using QGNSS, I noticed that they were reporting that only GPS the L5Q signals (a data-free pilot signal) was being used instead of the data-bearing L5I signal (which includes navigation data) or a combination of both. QGNSS indicated that for Galileo the E5a signal was being used, and the B2a signals but not what component(s) (e.g., pilot-only or data-bearing) were being used.

I set the receiver to emit RTCM MSM messages and here is the output from RTKLIB:

image

This indicates that only the L5Q/E5a/B2a pilot-only messages are being output by the receivers.

I used RTKCONV to convert the RCTM output into RINEX 3.04 format, and the relevant lines from the output file are:

G    8 C1C L1C D1C S1C C5Q L5Q D5Q S5Q                      SYS / # / OBS TYPES 
R    4 C1C L1C D1C S1C                                      SYS / # / OBS TYPES 
E    8 C1C L1C D1C S1C C5Q L5Q D5Q S5Q                      SYS / # / OBS TYPES 
C    8 C2I L2I D2I S2I C5P L5P D5P S5P                      SYS / # / OBS TYPES

…where “G” = GPS, “R” = GLONASS, “E” = Galileo, “C” = BeiDou. The observation codes confirm that only the data-free pilot messages are being output by the receivers for GPS, Galileo, and BeiDou, while the data-bearing messages are not being output.

Hat tip to bamarcant who first prompted me to look into this a bit more starting with this comment.

I have the following questions:

  1. Is this expected behavior?
  2. Can the receivers be configured to receive data-bearing L5 signals (e.g. GPS L5I, Galileo E5aI, etc.) and output RTCM messages for those signals? (Either by replacing the pilot-only messages and outputting data-only messages, or by outputting both pilot-only and data-bearing messages?)
  3. If not, is this functionality something that could be enabled with a future firmware update or is that something baked into the hardware?

For reference, the firmware version numbers for my DA and BS receivers are, respectively,

$PQTMVERNO,LC29HDANR11A01S_RSA,2023/03/02,12:43:39*21
$PQTMVERNO,LC29HBSNR11A01S,2023/02/13,10:14:06*27

Thank you.

2

Hi heypete

  1. The search status is in line with the expected behavior.
  2. LC29H supports switching between single-band and dual-band configurations, but does not support switching of L5 channel Signals.
  3. There is no development plan at present.
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