Oblique Frame Altitude · Photo Flight Tools


1  effSpan = spanAlong × 1.20  (10% margin each side)
2  R = effSpan/2 ÷ tan(HFOV/2)     floor: R ≥ 2,000 ft
3  H (AGL) = R × tan(depToCentroid)  → round UP nearest 100 ft
4  MSL = H_AGL + terrain     No fixed buffer (PDF v8)
5  Near-edge check: if atan(H / (R − L/2)) > 37.5° → fly R_wide on end passes

Property KMZ

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Drop KMZ / KML or click to browse

Property boundary polygon · Google Earth export

— ✓ LOADED

OBB long axis (spanAlong)—

OBB short axis (spanPerp)—

Max diagonal—

OBB bearing—

Camera & Lens

Sensor width (mm)

Sensor height (mm)

Focal length (mm)

HFOV 65.3° VFOV 46.2°

Flight Setup

Depression angle — 19°

19°

Camera axis below horizontal. 19° = PDF default. 15–25° typical for wide orbit.

Depression (°)

Crosshair — 67% from top

67%

Where OBB center sits in frame. 67% = bottom third (PDF default).

Crosshair (%)

Margin each side — 10%

10%

Padding on each side of OBB long axis before computing orbit radius.

Margin (%)

Terrain MSL (ft) — highest in KMZ bbox

Highest elevation within the property bounding box. Used as terrain baseline. In production this is fetched automatically from the Google Elevation API.

Near-edge R_wide (ft) — computed automatically

If near corners clip below usable frame edge, fly this wider radius on long-axis end passes. Computed automatically from H and spanAlong.

Compute

① Terrain

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② Geometry & R

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③ Near-Edge

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④ Flight Altitude

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Minimum flight altitude · oblique wide frame

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feet MSL

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AGL

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ft above terrain

Orbit radius R

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depToCentroid

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effective angle

effSpan

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Step-by-step calculation

Geometry diagram

Formula: Terrain baseline + photo geometry (min 1,000 ft AGL) + orbit arc anomaly check (R ± 500 ft, full 360°) + 1,000 ft clearance if needed
Source: Ryan M. Short · Red Wing Aerials · Aerial Photography Altitude Planning Math (2026) · www.PhotoFlightTools.com
Validated: N2759V C177RG · D850+28mm · DFW-Cleburne 1,384 ac · dep=19° · R=13,835 ft · H_final≈8,007 ft AGL