PULSE FIRMWARE 4.0 PREVIEW

Available Fall 2013,  Pulse Firmware 4.0: "Assisted Fine Search and Probing Indication"

Beacon technology has evolved rapidly in the last ten years: digital transceivers, distance and direction displays, signal separation technology, marking capability, vital data...the list goes on. 

Meanwhile, rescuers have also become more aware of the importance of systematic probing (spiral shaped at 25cm increments, see image at right) and strategic shoveling.

For a complete explanation of Conveyer Belt Shoveling see page 51 of the Mammut Pulse Reference Manual which you can download here: http://www.mammut.ch/en/avalanchesafety_barryvox_manual.html

When studying rescuers performances during beacon drills, there is a clear pattern: Signal Searches and Coarse Searches are relatively easy. Fine Searches demand methodical practice to ensure a smooth transition into the Pinpointing Search (probing) which is clearly the most important part of the search itself. 

In order to encourage more accurate and speedy Fine Searches and to improve the transition from Fine Search to Pinpointing, Mammut has introduced PULSE Firmware 4.0. This firmware update will be available in the Fall of 2013. Currently, this is a PULSE only upgrade (not available for the Element.)

Assisted Fine Search and Probing Indication

The two last phases of the search take place in the immediate vicinity of the buried subject. Whereas the “fine search” is carried out with the transceiver, “pinpointing” for the buried subject is done by the probe in a spiral shaped search pattern and concludes the search with a physical probe hit. The transceiver search for a buried subject in the last few meters of the search is a challenging compromise between search time and search accuracy – in particular for companion rescuers with limited training. Furthermore, many rescuers struggle with the decision when to stop transceiver search and start probing - always trying to get even closer with the transceiver, even though the required fine search precision for a human body sized object has already been achieved and only the immediate application of the probing spiral further shortens search time.
Up to a few years ago, a bracketing method was applied by all user groups while fine searching with the transceiver. Bracketing allows precise searches in shallow to medium burial depth, but requires an extensive level of training and routine for fast and precise results. Due to the often inefficient and unsystematic approach, the majority of the users spent far too much time in this phase compared to the gain of search precision they were able to achieve. 

This lead to the development of the “airport approach” method, which describes the last phase of the transceiver search as an analogy to landing an airplane on the runway of an airport and therefore a continuation on a straight line avoiding any bracketing. 

The "airport" method lead to considerably faster search times, however, when searchers did not properly follow the direction indications on the screen while approaching the immediate vicinity of the buried subject, the straight line of the “runway” was imprecisely aligned and lateral offsets were likely and lead to increased times for probing. Independent of the alignment of a “runway”, the lowest distance indication approximately appears were the rescuer is in the closest point between the “runway” and the buried subject. In an optimal case, this is directly above the buried subject, if the “runway” is not optimally aligned, the lateral offset approx. is in a 90 degree angle from it.

Searching for a better performance in transceiver search in close proximity to the buried subject independent of the user level, the balance between search precision and search time needs to be optimized. A totally new approach has been taken concerning high precision fine searching: With digital transceiver technology, the lowest point in distance indication based on signal strength received in all antennas (3D) of the device has become the determining criteria on where to change direction while bracketing or to start probing. Unfortunately, geometry makes the changes in distance indication in the last few meters above the buried subject become less distinct the deeper the burial. Therefore, the search accuracy of this approach decreases with increasing burial depth. On the base of “fine searching in a circle”, a high precision search system designed for deep burials, the new approach analyzes the vector of each antenna individually, and compared to the 3D-based distance indication, more accurately determines where the rescuer needs to change axis while bracketing in fine search and where spiral probing should be initiated.

 To conclude, the assisted fine search and probing indication:
- overcomes the problem of traditional bracketing by indicating where and when to change direction - overcomes the problem of imprecisely aligned “runways” applied in the “airport approach”- combines the precision of “fine search in a circle” with the speed and ease of the “airport approach” - optimizes the search time by indicating where and when stop fine search and start probing