Multiple Burials; Special Techniques - bca TRACKER DTS Owner's Manual

Operating Instructions
Move your transceiver very slowly in a straight line along the
surface of the snow during the final three meters of the fine search.
Ignore sudden fluctuations in distance and direction, often followed
by no distance reading and/or "SE" in the distance indicator. These
"spike readings" mean you are very close. The lowest reading will
be near this point.
From the point where you have located the smallest reading,
"bracket" at 90-degree angles to the left and then to the right in
search of a lower reading (Figure F). Repeat if necessary along both
axes. Begin probing at the lowest distance reading.
Probing/Pinpointing: At the point
where the distance has reached a
minimum, probe the area in concentric
circles, with each probe hole about
10 inches (25cm) apart. Your probe
should enter the snow perpendicular
to the slope. Once you have confirmed
the victim's location, leave the probe
in the snow.
Shoveling: While shoveling
might seem elementary, it usually
consumes the majority of time
during an avalanche transceiver
rescue. For best results, start
shoveling just downhill of the probe.
Make your hole one "wingspan"
wide and excavate downhill about
1.5 times the burial depth.
For more advanced shoveling techniques, see our website:
www.backcountryaccess.com.

Multiple Burials

If you begin to receive more than one set of signal data, you probably
have several victims within your receive range. Stay in search (SE)
mode, and focus on the closest distance reading, attempting to
engage that signal in the center search light. If you are roughly the
same distance from both transmitters, the Tracker will often flash "SE".
Once you are significantly closer to one signal—and within about
ten meters of it—the Tracker DTS (in SE mode) will "lock" onto
that signal and mask out the others. Once you are locked in, the
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CM CM
1.5 x
burial depth
Tracker will behave very similar to how it does in a single transceiver
search. Pay attention to the readings you last received from the
other transceiver; they will give you an indication of where to go after
finding the closest one.
Figure H
Search (SE) mode
In search mode (SE), only the
strongest signal (transceiver 1)
is shown. Signals further away
are received (transceiver 2), but
not shown in the distance and
direction display.
Once you have located the first transceiver, turn it off if you
determine the conditions are safe. If this is not possible, you might
already have a good idea of where transceiver 2 is located. In that
case, move in that direction until the Tracker isolates that signal.

Special Techniques

In most cases, multiple burials are approached as a series of single
burials. However, special techniques might be helpful if the victims'
transceivers cannot be turned off and there are several rescuers
available (so some can start shoveling while the best transceiver
user continues searching). These techniques are only necessary for
close-proximity situations, where two or more victims are suspected
to be very close to each other. If the victims are located less than
about five meters from each other, then it is possible to move past
a signal without it being detected. If the victims are suspected to
be further apart than this, then it is quite simple to continue on your
signal search until the second victim's signal is captured and isolated
by your Tracker. In the case of suspected close-proximity multiple
burials (with more than one rescuer available), we suggest the
following special techniques:
Three-Circle Method: This technique involves remaining in SE
mode and making concentric circles around the location of the first
victim until another signal is detected. It is most effective in large
deposition areas and low-angle terrain.
Operating Instructions
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