Snow Shelter Signaling
Edit on GitHubSignaling from inside a snow shelter: how the beacon's signal escapes, the antenna placement, and the survival sequence.
Snow Shelter Signaling
A snow shelter (igloo, snow cave, dugout) is the correct response to a storm or a night out. It is also a radio problem: the signal must escape the snow around you.
How snow affects the signal
Wet snow absorbs 433 MHz strongly; dry, fresh snow less so. A beacon inside a shelter with a meter of wet snow above it can lose 20+ dB (see Snow and Signal Behavior). The signal does not die entirely: it escapes through the entrance and any thinner walls.
The antenna strategy
| Placement | Effect |
|---|---|
| Buried in the snow wall | Worst: full absorption |
| At the entrance, pointing out | Best: the path is open air |
| On a pole through the roof vent | Good: above the snow |
| Against the wall, high | Acceptable |
The rule: the antenna wants the least snow between it and the sky, and the entrance is the natural escape hatch.
The survival sequence
- Shelter first: the beacon runs for hours, the person does not (see Hypothermia Recognition).
- Then deploy the antenna at the entrance.
- Then confirm: one burst decoded by a receiver at the surface (see Pack Check Routine).
- Then keep the schedule: the repeating bursts are the status report.
The marker
A visual marker at the entrance (a pole, a colored item) complements the radio: searchers homing on the beacon see the marker for the final meters (see Homing Technique).
Related pages
- Snow and Signal Behavior for the physics
- Winter Operations for the season
- Signaling Techniques for the toolbox