Stuck on Float, or RTK keeps dropping

Corrections aren't reaching the rover, or arrive late Most likely

Check:

1. On the Ditch Assist Home screen, tap Pre-Flight Checks, the orange button at the bottom of the right-hand column.
2. Find the Corrections row, near the bottom of the window.
3. Read it. With an Emlid Reach, DIG or Bluetooth receiver it shows the correction age in seconds: green at 2 seconds or less, amber up to 10, red above. Climbing past 10 seconds means corrections aren't getting through.
4. With a control module the row only says Active (on RTK) or Not reported. Check the receiver's own display for its correction status.

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On an Emlid Reach, the GPS Info window (tap the GPS badge) also shows Correction Age. A Reach reports 0.0 s even when no corrections arrive at all, so go by the fix on the badge, not by that number.

Fix:

1. Go to the base. Check it's switched on and sending corrections.
2. Check the base and the rover use the same radio channel or frequency.
3. Using an RTK network (NTRIP) or cell corrections: check the receiver's internet or cell connection is up.
4. Emlid base: in the tablet's Wi-Fi list, join the base's own hotspot.
5. In Ditch Assist, tap Settings, the fourth button down the right-hand column.
6. Scroll down to the very bottom of Settings (how to scroll).
7. Tap Emlid Diagnostics. It reads the base and compares it with the Ditch Assist Base setup.

Full base setup: Set up a base station.

Poor sky view

Check:

1. Open Pre-Flight Checks (orange button on the Home screen).
2. Read Satellites (third row): green at 14 or more, amber at 8 to 13, red under 8.
3. Read DOP (fourth row). HDOP above 2 means weak satellite geometry.

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Fix:

1. Move away from tree lines and buildings and wait for the fix.
2. Mount the antenna high, clear of the cab and frame.

Too far from the base

Check: How far is the machine from the base? For a steady RTK fix, stay within 2 miles of your own base. Is there a hill or a shelterbelt between them?

Fix: Move the base closer to the work, in line of sight, or raise its radio antenna.

The base sends fewer constellations than the rover tracks

Check: Many satellites tracked, but the fix won't settle and HDOP sits at 1.0 or above.

Fix: Have the base send GPS, GLONASS and Galileo corrections. Programming an Emlid base as Base in Emlid Diagnostics does this.

Sky view blocked along part of the field Most likely

Check: Note where it drops. The same spot every pass means trees, buildings or a hill.

Fix: Slow down through those spots and wait for RTK Fixed. Survey or grade those stretches when the fix holds.

The correction link drops out

Check: Watch the Corrections row in Pre-Flight Checks, or Correction Age in the GPS Info window. Does it climb at the moment the fix drops?

Fix: Move the base closer or higher. Check the radio antennas and cables. Using NTRIP: check the cell coverage.

Power dips to the receiver

Check: On implement kits the module powers the receiver. Are the power-harness fuses pushed fully in, and does the harness go straight to the battery?

Fix: Fix the power connection. See Connect the power harness.

The base moved, restarted or lost power

Check: Go and look at the base.

Fix: Restart it on its point. If it moved or was set up somewhere else, recalibrate to your benchmark before grading: see Grade is off.

It drops over bumps

Check: The drops line up with rough ground, not with places.

Fix: Something may be loose inside the receiver or antenna. Call a product specialist.

Space weather

Check: Everyone in the area has trouble at the same time. Check the space weather forecast at swpc.noaa.gov.

Fix: Wait it out.

No RTK corrections are arriving at all Most likely

Check: GPS on the badge means no corrections. DGPS means only a differential fix, good to about a metre. Pre-Flight Checks shows Corrections as Not reported.

Fix: Work through corrections not reaching the rover above. A John Deere StarFire that shows DGPS while its own display says RTK is a special case: see The receiver says RTK, Ditch Assist says DGPS.

It isn't RTK

Check: Which service does the receiver run? SF1, WAAS and OmniSTAR L1 aren't compatible. SF2, SF3, CenterPoint RTX, TerraStar and Atlas aren't RTK, even when the receiver calls them that. The badge may show PPP (amber, like Float).

Fix: Use real RTK corrections: your own base, in line of sight and within 2 miles, or an RTK network. On anything else, expect the blade to move up and down as the elevation drifts. See Correction sources.

The base isn't on the air yet Most likely

Check: Has the base finished its 2-minute averaging after start-up? Is its Base output 1 set to LoRa radio?

Fix:

1. Wait for the averaging to finish.
2. In Emlid Flow, the base should read Correction input Off, Base output 1 LoRa radio, Base output 2 Off.
3. Or let the app set it. In the tablet's Wi-Fi list, join the base's own hotspot.
4. In Ditch Assist, tap Settings, the fourth button down the right-hand column.
5. Scroll down to the very bottom of Settings.
6. Tap Emlid Diagnostics. The app reads the receiver.
7. Tap Configure, bottom right.
8. Tap Base (the top card).
9. Tap Program receiver and wait for Programmed as Ditch Assist Base.

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Base and rover radios don't match

Check: Compare the LoRa frequency (between 902.000 and 928.000 MHz) and the air data rate (18.23 kb/s) on the base and on every rover.

Fix: Use the same frequency on all of them. When you program a receiver, type it in the LoRa frequency (MHz) box. The app refuses a frequency outside the receiver's band: Enter a frequency between … and … MHz.

The rover's radio is still set as a base output

Check: On the rover, look at Base output 1 and Base output 2 (Emlid Diagnostics lists both).

Fix: Both must be off, and Correction input set to LoRa. Programming the rover as Rover or Lite Rover in Emlid Diagnostics does it for you.

The base radio is too weak for the distance

Check: How far is the rover from the base? Is the correction age climbing?

Fix: On an RS4 base, use Switch base power to 1000 mW in Emlid Diagnostics.

The radio can't carry three constellations at 1 Hz

Check: At 18.23 kb/s the LoRa link can't always fit GPS, GLONASS and Galileo at 1 Hz. When the app programs a base it lowers one constellation to 0.5 Hz and tells you: The radio could not carry 1 Hz on every constellation. Corrections now go out at: ….

Fix: Nothing to do unless RTK is slow to fix; then check the LoRa link. Setting it by hand in Emlid Flow, lower GLONASS (1084) to 0.5 Hz first, then Galileo (1094), then GPS (1074). See Set up a base station.