Observer reported a UAS making repeated low altitude passes over a neighborhood.

Narrative

When - XA:00 on Day 0 with a follow-up reading at XA:19. Where - My residence.What I saw - A DJI Mavic 3 flew low over my front yard and the neighboring houses on the east side of the block. - The drone made a series of east-west passes; appearing to follow a straight line back and forth across the street. - Directly over my house the drone was lower than 27 m (I could not get an exact number; but it was clearly below the 27'm I measured later).How I documented it 1. Photos - I took two pictures of the drone while it hovered over my yard at XA:00. 2. An appMake/Model: DJI M3EHeight: 27 m (this reading was taken after I walked a few blocks east; not at the exact spot of the house)Speed: 8.3 m/s I walked a few blocks east and re-scanned; at XA:19 the app still showed the same serial number and altitude; confirming it was the same aircraft. I saved a screenshot of the app screen. 3. Duration - The drone continued flying past my house and disappeared from view around XA:30 - XA:35.Why the flight stood out - The altitude (approximately 30 ft AGL and even lower directly over my yard) is lower than typical survey flights; which usually stay higher to cover a larger area. - The repeated east-west passes over residential yards suggested a mapping or photogrammetry mission; but I did not see any crew on the ground or a notice of data collection.