State-run network
Free
Alabama DOTDepartment of Transportation. The state agency that runs many of the free state RTK networks.Full definition
Good to know: Free (registration required)
Where it works
1 stateState-run network for Alabama.
All plans
| Plan | Price | Term |
|---|---|---|
| Access | Free (registration required) |
Coverage
- Where it works
- State-run network for Alabama.
- Stations
- Not published; the public SourcetableThe list of every mount point a caster offers. Your app shows it when you connect without picking one.Full definition listed 10 mountpoints on Oct 17, 2026 (network products plus any single-station streams)
- Needs cell signal?
- Yes: NTRIPThe standard way RTK corrections are sent over the internet. Think of it as internet radio for correction data.Full definition needs internet at the RoverThe receiver that moves around the job, like a survey pole or a drone. It uses the base's corrections to find its exact spot.Full definition (cell data or a phone hotspot). General rule, not an operator statement.
Connection settings
NTRIP caster
host205.172.52.26
PortA number that tells your device which "door" on the caster server to use. For NTRIP it's often 2101.Full definition10011
mountsRTCMIMAX, AutoMAX, CMR+IMAX, LeicaMAX, LeicaIMAX, CMR+NEAR, Near_Leica_GG, Near_RTCMv3_GG, NEAR_MSM4, IMAX_MSM4
Confirmed live: a public sourcetable request to 205.172.52.26:10011 answered on Oct 17, 2026 with 10 mountpoints.
- Mount types
- Nearest single station (NEAR_MSM4); older per-station RTCMThe common format RTK corrections are written in, so different brands can understand each other.Full definition mounts listed in 2017 ALDOT PDF
- Must send GGAA short message your rover sends with its rough location. VRS and nearest-station streams need it to know where you are.Full definition position?
- Yes for VRSVirtual reference station. The network blends nearby stations to create a pretend base right next to you, which keeps the baseline short.Full definition / network / nearest-base mountpoints (your rover must send its position as an NMEAA common text format GPS receivers use to report position and status. GGA is one NMEA message.Full definition GGA message). General rule based on the mount types.
Sign-up steps
- Register an account in ALDOT's Spider Business Center (SBC)
- Log in and request the RT product
- Set your rover as an NTRIP client with your ALDOT username and password
- Sign-up page
- Go to sign-up →
Fine print
- Last checked
- Oct 17, 2026
Conflict resolved: operator SBC lists 'ALL RT Products' with no price; no payment step. CasterThe internet server that hands out correction streams. Your rover logs in to it, like tuning into a radio station.Full definition details are given after login.
States covered1
Not listed by the operator: free trial, discounts, what's included, a coverage map and a few other details. Ask them before you sign up if these matter to you.
No user reliability reports yet. Used it in the field? Tell us how it went.