GPS Info Popover

What it is

The GPS accuracy badge in the top-right of every map screen shows your current fix quality at a glance — colour-coded green / yellow / orange / red, with a label and your satellite count. The on-screen labels are exactly: RTK (RTK Fixed), FLOAT (RTK Float), DGPS, GPS (standalone fix), NO GPS, plus PPP (precise point positioning) and SIM (simulator).

Tap the badge to open a modal popover that lays out every GPS detail the connected source provides. The popover sits above the rest of the screen so it never gets blocked by chevrons, the bucket gauge, the lightbar, or any other on-map overlay. Tap outside the popover or tap the X in the top-right of it to close.

The popover is useful any time you're troubleshooting an odd fix — sketchy elevation readings, lat/lon jumping around, the badge stuck on FLOAT when you expect RTK. It shows you exactly what the GPS source is reporting so you can confirm whether the problem is the receiver, the corrections feed, or something further downstream.

What the popover shows

The popover groups the details into two sections separated by a divider.

Top section — fix quality and source

• Source — where the GPS feed is coming from. One of:
  • Simulator — you're running a simulated machine.
  • Bluetooth GNSS — an external receiver paired over Bluetooth.
  • DIG Module — the excavator DIG module.
  • Ditch Assist Control Module — the control module's onboard GNSS.
  • Not connected — no source is active.
• Status — fix quality label (matches the badge colour). RTK (RTK Fixed, green) is the only fix quality Ditch Assist endorses for survey and grading — every elevation you record or grade to depends on it. FLOAT, DGPS and GPS are shown so you can see what the receiver is doing while it converges, not as working modes: with the RTK Filter on (the default) the app will not survey or grade on them, and if you switch the filter off to work on a lesser fix, the accuracy risk is yours. The one documented exception is John Deere StarFire SF-RTK, which reports DGPS over CAN even while it is on RTK corrections — that is what the RTK Filter setting is for (see Settings). The badge can also over-promise: satellite-delivered correction services such as Trimble CenterPoint RTX, Hexagon/NovAtel TerraStar-X and TerraStar-C PRO, or John Deere SF3 are precise point positioning (PPP), not RTK, yet many receivers report them with the same RTK fix code — the app cannot tell the difference. Ditch Assist endorses only true RTK from your own base station or an RTK network (NTRIP / VRS); grading on a PPP service, whatever the badge says, is at your own risk. NO GPS means you have nothing.
• Satellites — how many GNSS satellites the receiver is tracking.
• HDOP — horizontal dilution of precision. Smaller is better; under 1.0 is excellent, over 5.0 is poor geometry.
• PDOP — three-dimensional dilution of precision. Only shown when the source supplies it (control modules today; other sources show no row at all).
• Correction Age — how many seconds since the last RTK correction arrived from the base station. Under 5 s is healthy. Climbing past 15-20 s means corrections aren't reaching the rover and your fix will drop. Shown for DIG and Bluetooth sources; not exposed by the control module wire formats.

Bottom section — position and elevation

• Latitude and Longitude — to 7 decimal places. That's about 11 mm resolution at the equator, fine enough to see your RTK micro-movements (sub-cm jitter on a stationary antenna). If lat/lon are stuck on the same number for several seconds, the GPS feed has frozen — recover by tapping into the connect step.
• Elevation (ortho) — your orthometric height above sea level (in feet or metres, matching the Units setting). This is the elevation the rest of the app uses everywhere — survey, BM, grading target, all of it.
• Geoid Separation — the difference between the WGS84 ellipsoid and the geoid (sea level surface) at your location. Geoid models vary by region — in North America this number ranges from about −50 m to +30 m. Shown when the source supplies it: DIG, Bluetooth GNSS, and the Ditch Assist control module do; the simulator hides the row.
• Elevation (ellipsoidal) — your height above the WGS84 ellipsoid, which is orthometric + geoid separation. The raw value GPS receivers compute before any geoid correction. Shown only when geoid separation is available.
• Speed — current ground speed (in mph or km/h, matching the Units setting).

Why three elevation numbers?

GPS receivers compute height above the WGS84 mathematical ellipsoid — the ellipsoidal number. But the elevation that matters for grading is height above the geoid (effectively sea level), which is what surveyors use. Subtracting the geoid separation from the ellipsoidal value gives you the orthometric elevation that the app actually uses.

You don't need to think about this in normal operation — the app handles it automatically. The popover shows all three so you can spot misconfigured geoid models in the receiver (e.g. wrong region) when troubleshooting an unexpected elevation offset.

Reading the staleness dim

If the GPS feed goes quiet for longer than the GPS Stale threshold (default 5 s), the badge dims to 40% opacity even before the 10 s watchdog tears the connection down. Tapping a dimmed badge still opens the popover, and the numbers inside are the last values that arrived — so the popover is the right place to check whether a "no movement" complaint is actually "no recent fix".

Source-specific notes

• Bluetooth GNSS — the badge gets a small Bluetooth icon next to the GPS icon to distinguish it from controller-fed sources. The popover Source row reads "Bluetooth GNSS".
• DIG Module — elevation is bucket-tip corrected in hardware by the DIG module before it reaches the app. The number shown in the popover is at the cutting edge, not the antenna. This is why the app has no bucket-tip-height setting for the Excavator workflow.
• Simulator — fields update at the simulator's tick rate. The popover is otherwise identical to a real source.