ALDOT CORS
Free Alabama DOTDepartment of Transportation. The state agency that runs many of the free state RTK networks.Full definition
Coverage
1 stateState-run network for Alabama.
Everything you need to know
FreeType: State-run network
Price and plans
| Plan | Price | Term |
|---|---|---|
| Access | Free (registration required) |
Not published by the operator: free trial, discounts / exemptions, what's included.
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.
Not published by the operator: official coverage map.
Connection settings
NTRIP caster
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.
Not published by the operator: correction formats, satellites (ConstellationOne family of navigation satellites, like GPS, GLONASS, Galileo or BeiDou. More constellations means more satellites to use.Full definition), DatumThe starting point and ruler that coordinates are measured from. The same spot has different numbers in different datums.Full definition / EpochOne moment of GPS measurement. A receiver logging at 1 Hz records one epoch every second.Full definition / GeoidA lumpy, imaginary "sea level" surface around the whole Earth. Elevations are measured from it.Full definition, accuracy, receivers that work.
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 →
Not published by the operator: how long approval takes, who can sign up.
Fine print
- Last checked
- Oct 17, 2026
Not published by the operator: terms / user agreement, system status page, support.
Reliability reports
No user reports yet for ALDOT CORSContinuously Operating Reference Station. A permanent GPS receiver that records satellite data all day, every day.Full definition. We only publish reports from real users. Used it in the field? Tell us how it went.
Get a quote
Dealer quotes for ALDOT CORS (Alabama) aren't open yet. For now, use the operator's sign-up or contact link on each listing. Get the monthly email to hear when quotes open.