Comparing flights and building a progress timeline

Repeat flights of the same site turn into progress — if you can line them up. DroneFlow does that two ways, and emails you about it once a week.

Compare two flights

Select two finished projects of the same site and view them side by side, so you can see exactly what changed between dates — earthwork moved, structures added, material drawn down.

Build a progress timeline

Select between two and eight finished projects and open the Timeline. Press Measure progress and you get the cut, fill and net volume for every period — flight to flight — as a chart and a table, with a running total across the whole job.

Every period is measured over the same ground: the area all the selected flights share, at one resolution. That is what makes the rows comparable. Measured over each pair's own overlap instead, a bigger number could just mean a bigger area.

The running total is measured directly, first flight against last, rather than added up from the periods. Both are honest and they answer slightly different questions, so where the two disagree by much the panel shows you both figures instead of picking one.

Measure just part of the site

Draw a boundary with Measure an area before you press Measure progress, and every period in the series is measured inside it — one phase, one pad, one stockpile yard — across the whole history rather than one pair at a time.

When a period shows no number

A period that cannot be measured honestly is reported as not measurable, with the reason, instead of being given a plausible figure. The running total breaks there and the line continues dashed, because after a gap it is carrying on from the last known figure and cannot account for whatever moved in between. The usual reasons:

• The two flights are from the same day. That is a reprocess or one survey flown twice, not progress. The difference between them is measurement noise spread over the whole site.
• They were built by different pipelines. A project reconstructed here from raw photos and one taken from an export your desktop software already processed are not built the same way, so differencing them measures that as much as the ground. Compare like with like where you can.
• The surfaces do not line up. Aligning flights removes a constant offset between them; where they are warped relative to each other instead, what survives is not earthwork. Ground control shared across flights is what fixes this.
• A project has no elevation data. It is named and left out of the series rather than silently skipped. Reprocessing it generates the surfaces.

Which dates the timeline uses

Projects are dated by when you flew, not when you uploaded. For raw-photo projects DroneFlow reads the capture time out of the photos themselves. An already-processed export carries no flight date anywhere, so those fall back to their upload date — and the compare page tells you which projects those are, because if the two differ, the elapsed time between flights and any rate you read from it will be wrong. Volumes are unaffected either way: they are a difference between two surfaces and do not depend on the calendar.

The weekly progress email

Once a week, if one of your sites gained a finished flight in the last seven days, DroneFlow emails everyone on the account what changed: the two flights it compared, the cut, fill and net volume, the acreage measured, and a link straight into that site's timeline. Sites are worked out from the ground your flights actually cover, so repeat visits to one job group themselves without you filing anything.

It applies the same rules as the timeline, and it would rather say nothing than say something wrong: where a comparison is not measurable it tells you why, and if there is nothing worth reporting no email goes out at all. Every one carries an unsubscribe link.