Accessing a Public Base Station Network via NTRIP
There are many States in the US which provide free access to the State's CORS (Continuously Operating Reference Stations) network of base stations.The Sure-Path rover can receive corrections from such networks negating the need to set up and maintain a Sure-Path base station. States that we know about include: Alabama, Arkansas, Florida, Indiana, Iowa, Kentucky, Massachusettes, Michigan, Minnesota, Mississippi, Missouri, New York State, Ohio and Wisconsin. There are probably more and others provide subscription access at greatly varying annual rates.
To utilise such services, you need to register for an account with the operators of the NTRIP network. You will be given an "NTRIP User Name" and an "NTRIP Password". You will also be given the details of the server and port to connect to.
Once you have the required information, you can set up a Sure-Path rover phone. The example below shows how to configure the rover to access the Florida FDOT CORS network.
From the main Sure-Path screen, open the menu (top right) and select "GPS & Network Settings".
Before making changes to this screen, it is a good idea to note your existing settings. Then set the following:
RTK Error Source: "NTRIP Server"
NTRIP Server Address: Enter the URL or IP address you have been given.
NTRIP Server Port: Enter the port you have been given.
NTRIP Mountpoint: Click the menu item and assuming the above have been set correctly, a list of available Mountpoints will be listed as below. In the Florida example, "MSM4_iMAX" has been chosen a) because it is a "Networked Base" solution and b) because it utilises GPS, GLONASS and GALILEO satellite constellations, ie you want as many as are available. Some networks may even support the BEIDOU satellite constellation. An alternative would have been "MSM4_VRS". The system will still work with just GPS and GLONASS but will likely be less reliable in maintaining RTK Fix.
NTRIP User Name: Enter the User Name you have registered.
NTRIP Password: Enter the Password you have registered.
Close the Settings screen and continue as usual.
Note: Once you have mapped a course using a particular Mountpoint, then all boat lane tracking should be done under the same Mountpoint.