Ortovox S1 – Avalanche Beacon Review

WildSnow Beacon Reviews Overview

August 2011 Update: For the 2011-12 season, the S1 becomes the S1+, with the ability to switch between two different transmission antennas, so as to avoid a worst-case vertical-plane transmission. This means that (as explained in more detail in my initial review for the Ortovox 3+) some scenarios for suboptimal searcher-victim coupling are avoided and hence initial signal acquisition range will be longer. But the beacon still can’t do anything about the transmission being in the same horizontal plane as the searcher yet perpendicular to the searcher, or the transmission being partway between the vertical and horizontal plans. Bottomline is that on average your buddies will pick up your signal earlier than they would without the “+” (i.e., good!) but they still can’t count on a constant distance (i.e., no worse than with any other transmitting beacon). I’ll report back later on any changes I notice in the 2011-12 firmware (which will also be available for older S1 beacons), although you can probably count on various behind-the-scenes improvements in signal processing.

Back to the original review:

Ortovox S1 is an amazing technological tour de force, coupled with a radically different search screen. And as with some of its competitors, the techno tweaks only increase over time, as the firmware is upgradable. This review was originally written in Fall 2008, but information concerning firmware version 1.2.3074 (often referred to as version 3, after the leading digit of the last part of the code), follows at the end of the review (with a few relatively minor edits throughout the main body of the original review)

Interface and Controls
To switch S1 to transmit, rotate the switch at the top edge of the beacon 90 degrees. How to tell at a glance the beacon is transmitting? Look for the two flashing lights. The switch’s position for off versus transmit is not intuitively obvious when in the harness.

Switch to search by simultaneously depressing a button at the case’s hinge and flipping open the lid, realistically a two-handed operation. Revert to transmit by closing the lid. S1 will also revert to transmit within a programmable length of time if the beacon senses no motion.

The search interface has a LCD screen on the lid combined with two keys on the base, whose functions vary depending on the context but have some underlying consistency:

– Top button = mark/demarking/confirmation
– Bottom button = menu/rejection

I have found myself thinking of them as:
– Top button = enter
– Bottom button = tab

Ortovox S1 can check another beacon’s frequency drift (as does the Pieps DSP), transmission time, and total cycle length. But unlike the DSP, the S1 just reports a pass versus fail for each test, without reporting, say, just how much the tested beacon has drifted if it failed the frequency test. In my testing, I have found the S1 to be in agreement with the DSP’s tester.

The S1 has a compass (just like the Pieps DSP Advanced), thermometer (ditto), and clinometer. These are used internally as part of the search algorithms, and are also accessible to the user. Personally, I prefer to access such functions away from my avalanche beacon, and am not a big fan of leaning over on a ski pole pressed up against a slope to measure its angle with a beacon dangling loose from its harness. Same for trying to navigate with a compass that lacks any declination or bearing function. (Note: the Barryvox Pulse has an internal compass, which like the S1’s compass requires recalibration after replacing the batteries, but unlike the S1’s compass, its measurements are not accessible to the user.)

How It Works: Initial Signal Acquisition > Secondary Search Phase > Pinpointing

The S1’s display is radically unlike any other beacon: A grid-like display simultaneously shows each victim’s relative position complete with distance and (first introduced with firmware version 2.0 in Fall 2008), directional indicator for the strongest signal (largest victim symbol). The S1 can also display a sort of “windshield washer” graphic to direct the user to rotate the beacon.

Within three meters, as measured by the beacon, the display changes to a descending circle graphic, with distance readout down to 0.10m, plus arrows pointing inward or outward depending on the procimity of the victim.

The S1 also has an analog mode with sensitivity control, which seems to be intended mainly as a backup that can be accessed at anytime via the menu system.

How It Works: Multiple Burials

S1 magnifies the symbol for the strongest signal and displays an arrow toward that symbol along with distance readout, although the user can simply choose to head toward a different symbol. When a beacon is found, the user can then mark/mask it, and the S1 will graphically show a preference for the next strongest signal.

When the S1 detects more than four signals, “4+” appears in the upper-lefthand corner, which is a suggestion that the user access the menu to enter a 5m search-strip-width mode. This optional search mode can also be entered at any point via the menu.

How Well It Works: Initial Signal Acquisition > Secondary Search Phase > Pinpointing

The S1’s display is certainly different. Whether it’s better or merely a change from the traditional directional indicators (as originally pioneered by the Tracker), or the 360-degree rotating arrow on the Pulse, all depends on personal preference. The Fall 2008 addition of a directional indicator pointing to the strongest signal (i.e., largest victim symbol) is definitely an improvement upon the original release, and can be perceived as combining the best of both worlds. The directional indicator shown in the LCD is especially helpful when the victim symbol bounces around, which it often does, although to a small degree. The directional indicator therefore reinforces a common-sense conclusion to avoid this small “jiggling” effect.

Initial signal acquisition range is an improvement upon standard all-digital beacons (e.g., Ortovox D3 and original BCA Tracker), and roughly on a par with the Barryvox Pulse and BCA Tracker 2, but the Pieps DSP is still the range champ for full directional indicators, especially in worst-coupling alignment.

Once the signal is acquired, the S1 works best if you keep moving. Why? The answer is in how the 360-degree rotating arrow behaves. Although I am no electrical engineer, I did spent lots of time puzzling over the ahead-versus-behind detection of both the S1 and Pulse with an avalanche instructor who is also an electrical engineer. He concluded that the only way these beacons are able to detect ahead versus behind is the way you do with your own sense: whether the signal is becoming stronger or weaker. Keep moving and all is well. Stand still, and then any small drop-off in the signal strength, often caused by tilting the beacon slightly, will cause the S1 or Pulse to direct you (incorrectly) to turn around. So if in doubt, move!

Two situations in particular cause the ahead/behind function to become confused. First is the tricky perpendicular search, where initial signal acquisition occurs with the searching beacon pointing at a 90-degree angle to the target, and with the target pointing straight at the searcher. Any traditional directional beacon has a furthest-off-center directional indicator at about a 45-degree angle. What then happens is that either:
a. The correct furthest-off-center directional indicator appears, and once the searcher starts following it, the beacon will lead the searcher in a direct path to the target.
b. The correct and incorrect (i.e., essentially backwards) indicators trade back and forth, but the correct indicator wins out when the searcher hesitates a bit.
c. The incorrect indicator appears, and following it causes the distance readout to increase rapidly, which should be an obvious indicator for a searcher to turn around.

Okay, so that’s with a “traditional” directional beacon. What happens with the S1? See the latest results at the end of the review for the most recent firmware.

The other confusing behind/ahead situation is during a multiple burial, when once the first beacon is marked/masked, the next beacon might be behind or ahead of the searcher. During many multiple beacon searches, after the behind/ahead function performed flawlessly for the first beacon, I repeatedly had to turn around for the second beacon if I followed the rotating arrow’s behind/ahead distinction.

So even though the S1 does have a behind/ahead function, you still need to pay attention to whether the distance readout is getting smaller or larger. And once again, keep moving.

But don’t move too dramatically: If you do, S1 will chastise you with a little symbol (somewhat like a Masonic code) if you tilt too far away from level. I received this message incessantly at first when I opened the clamshell only to the angle that I was accustomed to on my flip-phone instead of almost all the way flat. (Unlike the Barryvox Pulse, which is programmable for multiple languages, the S1 communicates almost exclusively via universal symbols. At first they can be confusing.)

And on occasion, don’t move at all. Also similar to the Pulse, the S1 holds up a warning hand within a traffic-style octagon when it needs to think a bit. The user manual refers to a few seconds for the halt command but on a few occasions the warning hand has stayed up for a almost a minute, mainly when I randomly switched target beacons on or off. This seems to have been improved though with the new 2.0 firmware.

The backup analog works, although the average range result was slighter shorter than in regular mode.

For pinpointing, the descending circle graphic with distance indicators works well. The distance readout goes down to 0.10m, although I found that it dropped from 0.60m to 0.10m over the span of only about 0.12m. The box size is very small.

How Well It Works: Multiple Burials

I found the Ortovox S1 and Barryvox Pulse to be more reliable in both victim count and marking/masking than the Pieps DSP. Relative to the Pulse, the S1 has more difficulty with more than three or four victims, but realistically, that shouldn’t be a major priority in beacon selection.

The S1 and the Pulse essentially substitute model-specific familiarity for more general beacon searching skills. In other words, hand an S1 with no prior explanation to a user highly skilled in resolving multiple-burial searches on a beacon that has no special features, and the user (especially with no prior cell phone usage) might be confused with manipulating the soft keys correctly since the way these work is specific to the S1.

By contrast to above, a user familiar with the S1 can solve multiple-burial searches as if with x-ray vision.

But the S1 is still not perfect. Why? For the very same reason that your ear can have trouble discerning the presence of more than one sound. The different beacon signals can overlap and be tough to detect. But eventually, the signals’ different timing will cause them to diverge from another, and the S1 will correctly identify the number of beacons. In my testing with modern digital beacons as the target, this resolution is fast, usually before I even reach the first beacon.

This becomes a more significant problem when searching for older F1 beacons, which can cause persistent ghosting or undercounting.

Compared to the Barryvox Pulse with its scrollable list, the S1’s graphical display will be more intuitive to some users. However, remember that although the graphical attempts to show relative positions among beacons, given the relatively small screen and the nature of flux lines, this will almost never be a perfect map. Also, the S1’s two keys are arrayed vertically, but the prompts on the screen are arrayed left to right. The lid and base have lines visually connecting the keys to their screen prompts, but in my experience the top-bottom versus left-right disparity can be a bit confusing.

And like the Pulse, the S1’s excellent reliability in marking/masking seems to come with a drawback: the focus on the strongest signal may cause the S1 to effectively reduce its range for other beacons. But see the end of the review for the latest results with the current firmware.

Overall: To What Kind of Person Does This Beacon Appeal?

If you love the latest high-tech gizmos, then check out the S1 and the Pulse. A bit wary? You might still like the S1, but you might not -– be sure to try before you buy.

Overall: What Thoughts Go Through My Mind If a Partner Has This Beacon

“My partner had better be prepared to second guess the forward/backward indicator if the distance readout is increasing (instead of decreasing as it should).”

“My partner better be good at matching up the top and bottom soft key presses with what the screen indicates.”

“By learning and using the Ortovox S1, my partner will be a whiz at a multiple burial, but should be prepared for some possible small complications.”

***** JANUARY 2010 UPDATE *****

For Fall 2009 the Ortovox S1 is now in its third major version of firmware. The new 1.2.3074 S1 firmware code entails mainly behind-the-scenes improvements. The only immediately obvious change to the user is that the clinometer function now has a lock feature. (Great for measuring boot board ramp angle!)

Ortovox HQ in New Hampshire can perform this service, or see if a dealer is available near you:
http://en.ortovox.com/service/S1_update/USA.html
Worth it? Along with the general check-up that such a firmware upgrade includes, I did notice two behavioral changes in my testing this fall that would seem to indicate improvements in the processing algorithms.

First, in my Tricky Perpendicular Search Test:
https://wildsnow.com/1609/jonathans-wildsnow-beacon-test-notes/
. . . previously I had found that:
“The S1 essentially located the target in its “northwest” quadrant (i.e., if straight ahead were considered “north”) even though it really should have been either directly “west” or “east” (depending on whether I had the long axis of the beacon pointing to my left or right). When the target should have been located in the “west,” the “northwest” reading was only a minor problem. But when the target should have been located in the “east,” the “northwest” took me away from the target before the S1 corrected the behind/ahead distinction.”

With the latest firmware, I noticed significantly different behavior:
– When the beacon was initially pointing to the left, the S1 performed very well every time, either taking me to directly to the beacon or swinging me out on a trivially small arc.
– When the beacon was initially pointing to the right, the S1 very quickly went through a few confusing readings (e.g., right > left > right > back) before indicating that I should pivot the beacon back and forth, after which the S1 guided me correctly to the victim. My recorded times for this potentially confusing series of readings ranged for about half a minute to a minute, although a user who got thrown off by all this could of course fare far worse.

The sharp contrast in behavior between the initial orientation of the beacon (i.e., left versus right) was consistent across all several trials in each orientation. Overall, although my description of the new firmware’s behavior might not sound like an improvement compared to last year, in one orientation it performed nearly perfectly, and in the other it corrected relatively quickly after some initial confusion, and moreover did not actually send me off course more than a couple meters (before correcting).

Whether this test is a worthwhile simulation of a real-world rescue is debatable, but the improved results of such an odd initial coupling do show that the S1’s processing is undergoing improvements with each major firmware release.

Second, in my Triangle Range Test
https://wildsnow.com/1609/jonathans-wildsnow-beacon-test-notes/
. . . previously I had found that:
“And like the Pulse, the S1’s excellent reliability in marking/masking seems to come with a drawback: the focus on the strongest signal may cause the S1 to effectively reduce its range for other beacons. When I ran some tests to investigate this issue, with two beacons equidistant from my starting point, but far away from each other, the S1 initially showed both beacons. Once I got closer to the first beacon, the second beacon disappeared from the screen, and did not reappear until I turned off the first beacon, then quickly put the S1 into transmit and back into search again. The Pulse exhibited very similar behavior.”

I had no such problems with the S1 this year. Same improvement with the Pulse. This made me worry that somehow my testing protocol had changed from the prior year. So I tweaked the orientation and distance, tried again, and again. Still, no problems. Although I could be wrong, my conclusion is that both Ortovox and Barryvox have solved — or at least significantly mitigated — this previous drawback.

Manual

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WildSnow Beacon Reviews Intro and Index

(WildSnow guest blogger Jonathan Shefftz lives with his wife and daughter in Western Massachusetts, where he is a member of the Northfield Mountain and Thunderbolt / Mt Greylock ski patrols. Formerly an NCAA alpine race coach, he has broken free from his prior dependence on mechanized ascension to become far more enamored of self-propelled forms of skiing. He is an AIARE-qualified instructor, NSP avalanche instructor, and contributor to the American Avalanche Association’s The Avalanche Review. When he is not searching out elusive freshies in Southern New England or promoting the NE Rando Race Series, he works as a financial economics consultant.)