[Ideas] GPS-RTK about lysmarine_gen HOT 6 CLOSED

https://github.com/rtklibexplorer/RTKLIB

from lysmarine_gen.

Also relevant
DIY satellite compass

https://panbo.com/marineelectronicsforum/projects/diy-satellite-compass/

Easiest way to try this out:

• get two of of these 12 usd unit from Aliexpress, 25 usd total including the shipping

The unit can be any model, but it has to have ublox 8T or similar receiver that outputs raw GNSS messages, these are required for carrier phase measurements

• connect them to any laptop via two usb ports or get an usb hub

• set them say 1-2 meters apart. More is better. Sky has to be visible 360 degrees, boat is an ideal place to try, backyard of a house not so ideal.

• configure them to output raw gnss messages with free Ublox U-Center sowtware. Also select constellations to be used

The relevant messages are called UBX-RXM-SFRBX and UBX-RXM-RAWX. Good value for testing is say 1 Hz repeation rate. It can be set higher later on when everything works

GPS + Glonass + Galileo is a good starting point. 8T can only do three out of four at one time, 9T/9P can do all four + on dual frequency also - but on higher price

• Open the connection to the receivers with Rtknavi, which is included in RTKLIB package

• Select one USB/Com-port as base and another as rover

• Select constellations and set mode to moving base

• Wait till it shows first "float" (partial solution) and then "fix" (full RTK solution)

• Now the baseline heading indicated is true heading between the units

• From Rtknavi you can set to output this data as NMEA 0183. No N2K support unfortunatelly, that has to be dealt seperately

Anyway, here is a walkthrough for 30 minute and 25 usd satellite compass. As a bonus you will learn endless amount of new things about GNSS once you dig into the details.

ps. Laptop can well be a Windows laptop for trying and evaluating, though for long term use Raspberry with linux is cheaper, more stable and uses less power

from lysmarine_gen.

from:

https://www.navsparkforum.com.tw/viewtopic.php?t=424

There are several options to DIY make your own GPS Compass:

1. Two NS-RAW + RTKLIB
   http://navspark.mybigcommerce.com/ns-raw-carrier-phase-raw-measurement-output-gps-receiver/

2. two NS-HP receiver running in moving base mode
   http://navspark.mybigcommerce.com/ns-hp-rtk-capable-gps-gnss-receiver/

3. Two NS-HP-GL receiver running in moving base mode
   http://navspark.mybigcommerce.com/ns-hp-gl-rtk-capable-gps-glonass-receiver/

NS-HP-GL works with GPS + GLONASS, having more signals to work with, will get RTK Fix faster to have moving base heading, the vector direction from base antenna to rover antenna.

from lysmarine_gen.

https://wiki.openstreetmap.org/wiki/RTKLIB-compatible_GPS_devices

from lysmarine_gen.

http://www.navspark.com.tw/tutorial-4

from lysmarine_gen.

navspark px1125r $50 * 2 + two antennas cost

https://navspark.mybigcommerce.com/ns-hp-gn5-px1125r-l1-l5-rtk-breakout-board/

NS-HP-GN5 : PX1125R L1/L5 RTK BREAKOUT BOARD

https://navspark.mybigcommerce.com/blog/l1-l1l2-l1l5-rtk-module-selection/

Antennas
https://navspark.mybigcommerce.com/blog/antenna-selection/

from lysmarine_gen.