Monday, October 22, 2012

Snow and Avalanche Workshops 2012

This Autumn, Mammut has been busy attending ISSW as well as many of the regional snow and avalanche workshops which are becoming very popular in the western United States.

On October 13th, Mammut joined the community of Whitefish Montana to celebrate the second annual Northern Rockies Snow and Avalanche Workshop. Over 250 people attended. Some of the notable speakers included Karl Birkeland and Dale Atkins. Elyse Saugstad, who credits an airbag with her survival in an avalanche at Stevens Pass last year, also spoke.

On October 19, the Colorado Avalanche Information Center held the Colorado Snow and Avalanche Workshop (CSAW.) CSAW is always a very successful event and is an excellent opportunity to visit with the professional avalanche community before winter begins in earnest.

On November 2, Mammut will be at the Utah Snow and Avalanche Workshop. If you are able to attend, it is an opportunity to support your local avalanche and snow community. Come by the Mammut booth where you can update you Pulse firmware to 3.2 if you have not already or see this years Mammut Removable Airbag Systems (RAS.)

Friday, October 5, 2012

TECH TIPS: "Stop, Stand Still"

SLOW IS SMOOTH, SMOOTH IS FAST: Understanding the "Stop Stand Still" Message

Earlier today I posted an explanation on the "457 SEND failure!" Below, I explain the "Stop Stand Still" message.

First, it's necessary to have a little background.  All digital beacons have limitations. It is interesting to recall, as Manuel Genswein noted at this year's ISSW Avalanche Rescue Workshop that early on, the professional community was reluctant to switch to digital technology. Why was this? Well, some of it was probably fear of the unknown and a bit of techno-phobia. But another component was based on the fact that ANALOG tones are real, raw data. Analog does not have the potential to MISinterpret information, whereas DIGITAL interprets the analog information--think of it like communicating with someone through a translator--information can be confused and lost. Yet, by now we've all accepted digital technology as the de-facto standard. It is therefore important that we are aware of and accept the shortcomings of digital technology and have a backup plan.

What are the practical limitations of digital avalanche transceivers? 
The advantages of digital beacons are well known to us: it allows the beacon to provide us with a distance indication as well as a direction. This saves us time formerly spent comparing signal strengths of different tangents on a flux line (remember the technique used with analog only beacons?). In short, digital beacons allow us to be faster because we do not have to do comparisons or deductions.

Now, the limitations: Digital beacons arrive at their distance and direction indications by using a mathematical algorithm in a processor to interpret the raw data they are recieving--they are interpreting the strength of a given signal for us. In single companion rescue this is easy and virtually all digital beacons perform easily and with near-perfection. In multiple burial situations however, the beacon must identify patterns to distinguish between the signals. If, at any time, two buried beacons "beep" at the same time, then the searching beacon may be unable to distinguish between these signals--this is signal overlap. Luckily, in time the buried beacons' respective signals will drift apart, so the simple solution (if you know that you have overlapping signals) is to Stop, Stand Still and let the overlapping signals drift back apart, which normally only takes a few seconds.

In the above picture, I set the iPhone directly on top of the PULSE during start up. This message is more often a result of over-lapping signals, but I used electrical interference to initiate this message as I was unable to get the Stop Stand Still message prompt while searching for 5 beacons.

Aha! So, when you get this message, your beacon has actually identified the fact that you have overlapping signals (huh, that's pretty smart!) and advised you as to the best solution. Remember folks, "slow is smooth, smooth is fast." Sometimes our desire to move quickly to find our partner needs to be tempered to have the best (fastest) end result.

Allowing time to separate overlapping signals may not be acceptable to all users. Mammut recommends that mountain guides, ski patrollers, and other advanced users take advantage of the PULSE's Advanced Settings in preparation for the most difficult rescue scenarios. In the Advanced Settings, you can pre-set your beacon to provide you with both ANALOG and DIGITAL information simultaneously. Accordingly, you will never be confused when you encounter overlapping signals because you will actually hear the raw analog signals throughout the course of your search. This is the setting used by most professionals who are aware of the limitations of digital beacons. Be forewarned however, that effectively using analog and digital at the same time takes practice. 

Using Analog and Digital simultaneously, an advanced technique to utilize analog tones while still benefitting from digital distance, direction capability, and marking functionality takes practice. That topic will be covered in a future blog post.  (UPDATE: More info on this can be found HERE and ALSO HERE.)

I hope this helps you understand your PULSE a little better. If you have any questions do not hesitate to contact me (Doug Workman) at

TECH TIPS: "457 SEND failure!"

Welcome to Mammut's new avalanche safety blog, where we do our best to disseminate useful information about our snow safety products. In this post I will address a common question regarding the "457 SEND failure!" message you may have seen while using your Mammut PULSE avalanche transceiver.

457 SEND failure!
Yikes. Sounds bad doesn't it? Well, it is not.

All beacons are affected to varying degrees by electrical interference. At this year's ISSW in Anchorage, John W. Barkhausen presented a paper (THE EFFECT OF EXTERNAL INTERFERENCE ON AVALANCHE TRANSCEIVER FUNCTIONALITY, ISSW 2012) on electrical interference with digital beacons. What he found was that electronic devices such as digital cameras, smartphones, vhf radios, and GPS devices will interfere with a beacon (we have known this for a long time but Barkhausen's experiments made an effort to quantify the interference.)

Barkhausen found that a distance of 40 centimeters between the beacon and the interfering device usually remedied the problem. The bottom line is that a beacons' ability to function properly can be hampered by electrical output from smartphones, digital cameras, VHF radios and many other high frequency devices.

The above picture demonstrates a 457 SEND failure! I was able to initiate this error message by setting an iPhone directly atop the PULSE while it was in SEND mode. As soon as I moved the iPhone away from the PULSE it immediately removed the 457 SEND failure! message.

When the PULSE shows "457 SEND failure!", it is letting you know that is has identified electrical interference. When you receive this message, relax: there is nothing wrong with your beacon. Take a moment to move any electronic device away from your beacon (as Barkhausen found in his experiments, 40 cms is usually adequate.) Digital cameras have been found to be some of the worst offenders, but smartphones and VHF radios are common culprits as well, and we've even heard reports of the foil wrapper on an energy bar (in a chest pocket right on top of the beacon) leading to an error message. Practically speaking, moving the offending device about an arms-length from your beacon will solve the problem.

While this message may be alarming, it is important for everyone to realize that smartphones, cameras, and other electronic devices pose a real risk of interfering with a rescue. The PULSE will remind you if someone in my party has neglected to turn off one of these devices (turn off your iPhone!!!)

Bottom Line: All digital beacons will suffer from such electrical interference. If you see the "457 SEND failure!", address the problem if possible by moving the offending device or turning it off, and continue. It is possible that you could receive this warning in an urban setting due to electrical interference from large buildings, power lines and appliances. Obviously, in these circumstances you will need to be aware, though there is little you can do to remedy the problem.

I hope this helps you understand your PULSE a little better. If you have any questions, do not hesitate to email me at