What is a sector report in center pivot irrigation?
A sector report breaks a center pivot's circle into wedges, usually by degree of rotation, and tells you how each wedge is doing compared to the rest. Instead of treating the field as one undifferentiated circle, it treats the pivot the way the equipment works: span by span, nozzle bank by nozzle bank, moving through 360 degrees over the course of its run time. If sector 40 to 70 degrees is running dry while everything else looks normal, that's a localized problem, usually mechanical, and a sector report is built to catch exactly that pattern.
Most district engineers already think in sectors without calling them that. You know which quarter of a pivot is harder to see from the road, which span has given you trouble before, where the end gun cuts in and out. A sector report just puts a number and a map reference on what you already suspect, so you're not driving the circuit on a hunch.
How the report divides the circuit
Each report maps the expected water pattern for that specific machine (span lengths, nozzle package, end gun throw) against what's actually showing up on the ground. That comparison runs the pivot against its own geometry, which is what makes it a sector report instead of a generic field scan.
A typical breakdown might split the circuit into 8 to 16 sectors, enough resolution to isolate a problem to a quarter-span or so without pretending you can pin a single nozzle from overhead. When a sector's actual pattern runs noticeably drier or wetter than what the geometry predicts for that angle, the report flags it. Dry sectors usually point to a clogged or broken nozzle, a leak upstream of that span, or a pressure drop that's not reaching the far end of the circuit. Over-watered sectors can mean a stuck nozzle, a valve not closing, or an end gun running longer than it should on that pass.
Reading a weekly pivot report
The weekly part matters as much as the sector part. A one-time report tells you how the pivot looked on the day someone flew it. A weekly one tells you how the pattern is trending, whether a sector that looked borderline last week is now clearly dry, or whether a flagged spot cleared up on its own (a sprinkler head that unclogged, a pressure issue that got fixed). Weekly cadence is what lets you catch a nozzle failure in its second or third week instead of its eighth, and it's what lets you rule out one-off noise from wind or a single bad pass.
For a district engineer covering a lot of circuits, the practical value is in what the report replaces: the guesswork before you decide to go. Instead of driving out to eyeball a pivot because a renter called in, or doing the slow circuit-by-circuit windshield survey every few weeks, you get a report per pivot that already tells you which ones need a look this week and roughly where on the circuit to start. You still walk the flagged sector once you're out there; the report just tells you which pivot and which wedge to check first.
This is the deliverable Irrigation Monitor builds around: a per-pivot sector report run weekly against each pivot's own geometry, using multispectral and thermal passes to catch the application uniformity problems that a windshield survey misses until the crop damage is already visible.
If you're tracking pivot performance across a district and tired of finding dry sectors by accident, that's worth a look.