Backcountry Access Tracker DTS Instruction Manual - page 7
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indicator is increasing, you are on the same axis as the victim’s
signal, but moving in the opposite direction. Turn 180 degrees,
engage the center search light again, and continue your search
in the direction the Tracker is pointing. If you are stationary,
but the distance is significantly changing, you are probably
detecting the signal of another rescuer. Make sure all rescuers
are in search mode before continuing.
You may find that, while following the directional lights, your
route follows an arc. This is because the Tracker DTS performs
the coarse search using the "flux (or induction) line" method
(see Figure F). It follows the shape of the electromagnetic
signal, or flux line pattern, coming from the transmitting
beacon’s antenna. The distance displayed is the distance to be
traveled along that flux line, not the straight-line distance from
you to the victim.
A
B
Figure F
Flux lines
The Tracker follows the shape of
the electromagnetic flux lines coming
from the transmitting beacon’s
antenna. Your path during the fine
search will be either straight (point
A) or curved (point B), depending on
the orientation of your beacon when
the signal is first captured.
Note: the Tracker’s
transmitting antenna
}
is oriented at a 45-degree
angle to the long axis of
its case, as shown.
3.0
SE
1.0
SE
3.0
1.6
1.6
Figure G
Fine Search
Bracketing: When your distance
indicator reaches 3 meters, search
along a straight line until you have
passed the lowest distance reading.
Return to the lowest reading and
“bracket” in search of an even lower
reading. Ignore the directional lights
while in the fine search.
Operating Instructions
Fine Search: The fine search is the final part of the beacon
search, which is performed on foot with the beacon positioned
at or near the snow surface. The objective of the fine search is
to locate where the signal is strongest and to reduce the area
to be probed.
Move your beacon 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 G). 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 beacon
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.
Operating Instructions
˚
˝
˝
CM
CM
1.5 x
burial depth