Canopy Cutaway Manual

The Canopy Cutaway tool estimates a possible recovery search area using a selected cutaway point, forecast winds, estimated altitude, time, canopy condition, and optional spotter azimuths.

Inputs and controls

Input or control	Explanation
Selected cutaway location	The map point where the cutaway occurred or was estimated to occur.
Latitude / longitude	The coordinates for the selected cutaway location.
Cutaway altitude	Estimated altitude above ground level at the time of cutaway.
Cutaway time	The time used to select forecast winds for the estimate.
Canopy condition	The assumed condition of the cutaway canopy, which affects estimated fall rate.
Search width	Adjusts how wide or conservative the displayed search estimate should be.
Custom fall rate	Optional user-entered fall rate if a preset canopy condition is not appropriate.
Custom uncertainty	Optional uncertainty value used to widen or narrow the displayed search area.
Use ground spotter azimuth	Enables observer bearing inputs to help compare the forecast estimate with ground observations.
Add spotter	Adds a ground observer location to the map.
Spotter location	The map point where the observer was standing when making the sighting.
Azimuth, °T	The true bearing from the spotter toward the observed canopy or estimated direction.
Quality	The estimated reliability of the spotter bearing. Lower quality creates a wider bearing sector.
Clear spotters	Removes entered spotter references from the display.

Outputs and display references

Output	Explanation
Cutaway marker	The selected or estimated cutaway point on the map.
Estimated search area	The forecast-based area where the canopy may have drifted.
Nominal drift line	The central estimate from the selected inputs and wind data.
Fast / slow fall references	Alternate estimates based on fall-rate uncertainty.
Spotter markers	Ground observer locations entered by the user.
Spotter bearing sectors	Azimuth wedges from spotters toward the observed or estimated canopy direction.
Overlap area	Where wind-based estimates and spotter bearing sectors overlap, when applicable.
Map imagery	Geographic context such as roads, fields, water, trees, buildings, or property boundaries.

Open the Canopy Cutaway tool

Altitude source: barometric vs true

The altitude source setting changes how the Cutaway Canopy tool interprets the cutaway altitude. This matters because a GPS-derived altitude and a skydiving altimeter reading are not the same type of altitude reference.

True altitude source: Use this when the altitude comes from GPS or another source that is already reporting a true/geometric altitude reference.
Barometric altitude source: Use this when the altitude comes from an altimeter reading. Standard skydiving altimeters are barometric instruments, so an altitude read from an altimeter should be treated as barometric.

In practical terms, anything based on GPS should be treated as true altitude. Any altitude copied from an altimeter should be treated as barometric altitude. The barometric option exists because pressure-based altimeters can differ from true altitude under changing pressure, temperature, and calibration conditions.

If you are unsure which source you used, choose the option that matches where the number came from, not the device you typed it into. For example, a GPS coordinate or phone GPS altitude is true altitude, while a number read from a wrist, chest, or aircraft altimeter is barometric altitude.