bca Tracker DTS Instruction Manual page 7

2) If possible, use beacons of different brands as transmitters. This will allow students to experience their
differing pulse rates.
B) Show how the display looks with two beacons transmitting:
1) Using the same two transmitters, begin a secondary search from at least 20 meters away. Note what
the display looks like when they have both been detected. Often signals can be differentiated better
by slightly changing the orientation of the Tracker until the received signals are in different directional
windows.
2) Emphasize that the student should continue to strictly maintain their search strip width even after
detecting a signal. This will ensure that they will not bypass a weak or poorly oriented transmitter and have
to backtrack uphill after finding the first one. In a complex multiple burial, the primary search should not be
abandoned until the lowest distance reading is less than 20 meters.
3) If the two signals are easily differentiated, mark this spot and perform a search for the closest beacon.
Point out that you can always return to this point to search for the second victim.
C) Perform multiple search using three-circle method.
1) If the two signals are not easily identified, then introduce the three-circle method. This is the baseline
method for locating multiple victims using any avalanche transceiver.
2) Abandon primary search and pinpoint first victim. Take three steps back and search for second signal
in SE mode, maintaining three-meter radius around the first victim. Emphasize rotating the beacon slowly,
as on the primary search. Look for sudden change in visual display and audible tones, and for sharply
decreasing numbers. Test any such areas with a quick bracket.
3) If no signal is captured, take another three steps back and repeat—up to three circles (nine-meter radius).
4) Once a new signal is acquired, pinpoint by bracketing ("pinpointing on a line" is difficult in close-
proximity searches).
5) After locating each victim, it is important to complete
each circle if victims are still missing. Once all the circles
have been searched, return to the point at which the
primary search was abandoned. Continue the primary
search from here if victims are still missing.
The three-circle method is an excellent technique for
beginners, but requires inefficient movement through the
deposition area. The Tracker's special (SP) mode enables
more efficient searching in a similar circular pattern but
with the searcher remaining in place and rotating the
beacon rather than physically walking in circles. For more
information, see Advanced Tutorial.
-Tracker DTS Instruction Guide -
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Figure 2
3-Circle Method