State-run network
Free
Iowa DOTDepartment of Transportation. The state agency that runs many of the free state RTK networks.Full definition
Good to know: Free; renew every 2 years
Where it works
1 stateState-run network for Iowa.
All plans
| Plan | Price | Term |
|---|---|---|
| Access | Free; renew every 2 years |
Coverage
- Where it works
- State-run network for Iowa.
- 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 9 mountpoints on Oct 17, 2026 (network products plus any single-station streams)
- Needs cell signal?
- Yes, cellular data at the work site (Iowa DOT FAQ)
Connection settings
NTRIP caster
hostiartnrtk.iowadot.gov (165.206.203.10)
PortA number that tells your device which "door" on the caster server to use. For NTRIP it's often 2101.Full definition10000
mountsRTCM3_MAX, RTCM3_IMAX, RTCM3_NEAR, CMRP_NEAR, CMRP_IMAX, MSM_IMAX, MSM_NEAR, RTCM3_IAAMx, RTCM3_IAAM
Confirmed live: a public sourcetable request to iartnrtk.iowadot.gov:10000 answered on Oct 17, 2026 with 9 mountpoints.
- Mount types
- MAX and i-MAX network
- Correction formats
- RTCMThe common format RTK corrections are written in, so different brands can understand each other.Full definition.1, RTCM 3.2, CMR, CMRxTrimble's own compact correction format. Some networks offer it for Trimble gear and machine control.Full definition (GLONASS only on RTCM 3.x)
- Satellites (ConstellationOne family of navigation satellites, like GPS, GLONASS, Galileo or BeiDou. More constellations means more satellites to use.Full definition)
- GPSThe US satellite navigation system. People often use "GPS" to mean all satellite positioning.Full definition; GLONASS on RTCM 3.x only
- 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 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 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.
- Receivers that work
- Any recent rover that takes RTCM 3.1/3.2, CMR or CMR+
Sign-up steps
- Register in the IaRTN Spider Business Center (SBC)
- Subscription is free for two years
- Renew in SBC when notified
- Sign-up page
- Go to sign-up →
Fine print
- Last checked
- Oct 17, 2026
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.