RTK Rover Setup (NTRIP)

Prerequisites

• LC29H(DA) or LC29H(BA) variant (RTK-capable)
• NTRIP caster account (rtk2go.com is free — register with your email)
• Internet connection on the host device
• Clear sky view for GNSS antenna

Understanding NTRIP

NTRIP delivers RTCM3 correction data from reference base stations to your rover over the internet. Three roles are involved:

1. Caster — Central server that redistributes corrections (e.g., rtk2go.com)
2. Server — Base station uploading RTCM3 data to the caster
3. Client — Your rover, pulling corrections from a specific mount point

Setup with lc29h CLI

1. Install the CLI

   uv tool install lc29h

2. Connect and verify the module

   lc29h --port /dev/ttyS0 info

   Confirm the variant shows DA or BA.

3. Start NTRIP corrections

   lc29h ntrip start \
     --host rtk2go.com \
     --port 2101 \
     --mount NEAR_ME \
     --user your@email.com \
     --password none

   Replace NEAR_ME with a mount point near your location. Browse available mount points at rtk2go.com:2101.

4. Monitor RTK status

   lc29h --port /dev/ttyS0 monitor

   Watch the fix quality progress through these stages:

   • 1 (GPS Fix) — autonomous, ~1 m accuracy
   • 5 (RTK Float) — carrier-phase tracking, decimeter accuracy
   • 4 (RTK Fixed) — integer ambiguities resolved, centimeter accuracy

Setup with QGNSS (Windows)

1. Connect the LC29H(DA) via USB (install CP210x driver if needed)
2. Open QGNSS → select COM port (115200 baud)
3. Tools → NTRIP → NTRIP Client
4. Configure:
   • Address: rtk2go.com (or your regional caster)
   • Port: 2101
   • Username: your registration email
   • Password: none (for rtk2go)
5. Click “Update source table” — select the nearest mount point
6. Click “Connect To Host”
7. Monitor the Data Dock for RTK status

RTK Fix Quality Progression

Stage	GGA Quality	Accuracy	Typical Time
No Fix	0	—	Initial power-on
Autonomous	1	~1 m	1–26 seconds
RTK Float	5	~20 cm	10–60 seconds after corrections start
RTK Fixed	4	~2 cm	30–120 seconds after float

Tip

Convergence time depends on: baseline distance to base station (shorter is faster), satellite geometry (more satellites = faster), and correction stream quality (MSM7 > MSM4). Baselines under 10 km typically converge within 1 minute.

Troubleshooting

No float/fix after several minutes:

• Verify RTCM data is being received (check serial RX LED activity)
• Ensure GGA output is enabled (PAIR073) — the caster needs GGA for VRS
• Try a different mount point closer to your location
• Check that constellations match between base and rover

Frequent fix drops:

• Move antenna to better sky view — multipath from buildings degrades carrier-phase
• Reduce baseline distance (use a closer mount point)
• Ensure baud rate is high enough for RTCM3 throughput (115200+ recommended)

Public Casters

Caster	Host	Port	Registration
rtk2go	rtk2go.com	2101	Free (email)
UNAVCO	caster.unavco.org	2101	Academic
HKGS	landsd-gncaster.realtime.data.gov.hk	2101	psi_user / psi