SDZ Safety

skprconsulting · table-based surface danger zone

Install SDZ for offline field use

Safety tool — not a clearance. Default mode uses regulatory table Distance X. Metro-adjusted ballistics never undercut the table unless you explicitly allow it. Always identify your target and beyond.

Ammunition & terrain

Weapon / ammo / impact medium

Ricochet model

Batwing models ricochet “wings.” Cone is a simplified hazard cone. See Help.

Distance X mode

Metro-adjusted uses live weather + load BC/MV to estimate max range, then scales the SDZ. Table floor keeps you at or above DA PAM / DOE Distance X.

Allow under-table ballistic X (not recommended)

Firing geometry

Latitude (°)

Longitude (°)

Set the firing point with GPS, by typing coordinates, by tapping Pick on map, or by dragging the FP marker. Recompute after you move it.

True heading (°)

0 = North, 90 = East. SDZ math uses this as true heading.

Live reading is magnetic. Apply only if you accept that, or correct for local declination before computing. Not a substitute for a survey-grade azimuth.

Left limit / sweep (°)

Right limit / sweep (°)

Firing line width (m)

Total width of the firing line; split equally left/right. 0 = single firing point.

Height above ground (m)

Altitude MSL (m)

Environment (metro)

Weather loads after GPS or when you set a map point.

Metro is used for atmosphere density / sound speed when Distance X mode is metro-adjusted. Results are estimates; physics models are validated for trend, not certified for every load.

Map layers

Batwing

Dispersion

Sweep

Firing line

Terrain rays / hits

Roads / power

Buildings

Terrain & infrastructure risk

Auto-analyze after compute

Compute SDZ to run terrain & infrastructure analysis.

Safety checklist (human judgment)

Adequate backstop / berm

Know what is beyond the target

No people / livestock in zone

Legal / permission to shoot here

0/4 safety checks marked.

Risk layers are planning cues (DEM + OpenStreetMap). They do not authorize a shot.

Tap the map to set the firing point

Danger envelope

Batwing

Road in zone

Building

Terrain hit

Firing point (drag)

Welcome — SDZ setup

This app builds a Surface Danger Zone on the map from standard range-safety tables and your firing geometry. Calculations use metric internally; choose how you want numbers displayed.

Unit system

Heading reference

Default ricochet model

I understand this is a planning aid, not permission to fire, and that physics/tables must be used with judgment.

GPS stays on your device for solo use. Location sharing (if added later) will be opt-in only.

Settings

Unit system

Heading mode

Default ricochet model

Engine and ammo database remain metric. Only labels and form conversion change.

What is an SDZ?

A Surface Danger Zone is the ground area that may be endangered by projectiles, ricochets, or fragments when a weapon is fired. Military tables (e.g. DA PAM 385-63) publish standard dimensions by ammunition and impact medium (earth/water vs steel/concrete).

Batwing adds lateral ricochet “wings” using angles P and Q and distances Y/W from the table. Cone uses a simplified 30°/90° hazard cone. Your left/right sweep is the planned field of fire; dispersion is the weapon’s built-in angular allowance (often 5°).

Set the firing point with Use GPS, type lat/lon, Pick on map, or drag the FP marker. Use Compass assist only as a magnetic estimate. Metro weather feeds atmosphere for optional metro-adjusted Distance X (ballistic max range with a regulatory table floor). Wind deflection is informational only.

Install on iPhone / iPad

Open this site in Safari (required for Add to Home Screen).
Tap the Share button (square with arrow).
Scroll and tap Add to Home Screen.
Confirm the name and tap Add.

On Android Chrome, use the Install button when the browser offers it.