Before you start

You need four things in place before grading a ditch:

1. A high-accuracy GPS lock. The GPS Accuracy badge in the top stats bar should read RTK Fixed (green) — the only fix quality Ditch Assist endorses for grading. RTK Float (yellow) is not endorsed; if the app lets you continue on it (RTK Filter off), the accuracy risk is yours. No fix means no grading.

2. A connection to the controller. The WiFi indicator in the stats bar should be green. If it is red or grey, tap it and reconnect. See Getting Started for the connection sequence.

3. The correct blade height. The blade height tells the app how far above ground the GPS antenna sits. Because Ditching surveys the ditch with this app and then grades the design built from that survey, getting blade height right matters: an error here puts every grade target off by the same amount. Check Settings → SURVEY → Blade Height, or run Auto Measure before starting.

4. A survey or design loaded. You either record a new survey now, or load one from a previous session. The Slope-IQ designer needs surveyed terrain to work with.

About the benchmark

The benchmark (BM) aligns the GPS elevation frame with the survey elevation frame. You only need to set the BM when:

• You loaded a survey from disk in a different session, or
• The RTK base station has moved or rebooted since the survey was recorded.

If you survey and grade in the same session with the same base running, the BM is already aligned. The app prompts you when it thinks calibration is needed.