New Book on Kate M.

[Trail Boss]

According to this article she had a spot. Under the "review and analysis of the incident and death" they go into detail .. which is it she had a spot or PLB ?

The definitive answer to that question will need to come from someone who personally did an inventory of the equipment she had. It seems like for every "she had a SPOT" one can find "she had a PLB". For example, in this post, DougPaul cited a reference indicating she had a PLB.

If she had a SPOT, it makes the last part of this line, from Bloomberg's article, difficult to sort out:

...—an ACR *ResQLink *personal locator beacon (PLB), which Farhoodi had registered with the federal authorities that monitor all personal locator beacons in the U.S.

You do register a SPOT (with GEOS, a private organization) but not with "federal authorities that monitor all personal locator beacons in the US". Either someone doesn't have the story straight or she had both!?!

The CatskillMountaineer article describes the SPOT's operation in detail. It allegedly transmitted eleven SOS requests. Is this mentioned in Ty's book? In other reports about Matrosova? If not, who's right and who's inventing s**t? It's a wonder how these accounts can't agree on this important detail.



I have a quibble with CatskillMountaineer's conclusion that a SPOT is inferior to a PLB because its radio has a lower transmit power. It overlooks to mention PLBs and SPOTs don't communicate with the same satellite systems: COSPAS-SARSAT vs Iridium/Globalstar. It's not a straightforward apples to apples comparison. PLBs communicate with COSPAS-SARSAT satellites in different orbital planes including geostationary orbit which is far higher than Iridium/Globalstar. Each device's radio is tailored to operate reliably with its chosen satellite system.

They mention, but gloss over, that PLBs have a geolocation accuracy of 328' (i.e. 100 meters). However, they blame SPOT's retransmitted SOS signal, each time with a different geolocation, for wasting SAR's time and energy. Again, a bit too simplistic.

SPOT's basic accuracy is on the order of 10 meters which is the bog-standard for consumer devices. On a good day, it can theoretically outperform PLB in narrowing down your position. However, it was a terrible day. The temperature was at the extreme lower end of the SPOT's rated temperature band (probably much lower if you account for wind-chill). If nothing else, if you plan to travel in Antarctic conditions, a PLB may be the better choice because it is rated for use down to -40F.

Whatever she used, it failed her.

 

[DougPaul]

They mention, but gloss over, that PLBs have a geolocation accuracy of 328' (i.e. 100 meters). However, they blame SPOT's retransmitted SOS signal, each time with a different geolocation, for wasting SAR's time and energy. Again, a bit too simplistic.

SPOT's basic accuracy is on the order of 10 meters which is the bog-standard for consumer devices.

The 100 meter accuracy for a PLB is a limitation of the data transmission protocol, not the internal GPS. (The internal GPS probably has the typical 10 meter accuracy.) See http://www.vftt.org/forums/showthread.php?57671-Delorme-InReach for a more detailed discussion.

We should note that these accuracy figures are ideal-case numbers. In practice, the errors can be far larger.

In any case, the multiple locations obtained early in the search varied by far more than 100 meters and the point chosen for the initial search was far away from her actual location.

Doug

 

[Trail Boss]

Yup, we're on the same page here. A limitation of how many bits allocated to represent lat/long hamstring the PLB's accuracy.

I suppose the 121.5 MHz "homing" beacon could be used to zero-in on you ... assuming the SAR team has equipment to detect the signal. Although I believe the "homing" beacon was included because PLBs preceded consumer-GPS so they did not (could not) transmit coordinates.

In Matrosova's case, it is alleged that each successive SOS signal reported a different location. That's not too surprising for GPS. Stand in one place and the location's coordinates will drift slightly with each successive recalculation. Add sources of signal attenuation plus unfavorable satellite geometry and the "drifting" can be quite pronounced. So, do both SPOTs and PLBs use a freshly-calculated position for each SOS transmission? If so, both devices would be susceptible to reporting different positions for each transmission. Arguably, the PLB's reduced accuracy offers better odds for reporting significantly different locations.

Anyway, all academic because of the conflicting accounts of what she used to signal for help. Both devices have drawbacks that could have failed her on that terrible day.

 

[DougPaul]

I suppose the 121.5 MHz "homing" beacon could be used to zero-in on you ... assuming the SAR team has equipment to detect the signal. Although I believe the "homing" beacon was included because PLBs preceded consumer-GPS so they did not (could not) transmit coordinates.

The 121.5 MHz frequency is a partially discontinued emergency frequency, however some continue to monitor it or have equipment that can monitor it. It and the 406 MHz (PLB to Satellite) frequency can both be used to home in on the transmitter.

In Matrosova's case, it is alleged that each successive SOS signal reported a different location. That's not too surprising for GPS. Stand in one place and the location's coordinates will drift slightly with each successive recalculation. Add sources of signal attenuation plus unfavorable satellite geometry and the "drifting" can be quite pronounced.

Under good conditions, this drift is included in the accuracy spec and would usually stay within 10 meters of the correct location. Under less than ideal conditions the errors depend on more than just the antenna--the signal processing behind it has a very large effect on the observed errors under such conditions. (For instance, compare the Garmin 60CS and 60CSx. Identical antennas and cases, but the far more advanced signal processing in the 60CSx makes it far more tolerant of such factors as orientation, foliage, terrain, etc.) I have no idea how good the GPS chipsets used in PLBs and SPOTs are, however the better ones generally cost more and consume more power. (They might conceivably use cellphone chipsets which are presumably cheap and low power at the cost of performance.)

So, do both SPOTs and PLBs use a freshly-calculated position for each SOS transmission? If so, both devices would be susceptible to reporting different positions for each transmission.

I believe both use the most recent GPS location. (Nothing else makes much sense--an earlier location is just as likely to be inaccurate as the latest one and the victim might move. Also multiple locations would be a clue to the SAR folks that accuracy might be a problem.)

Arguably, the PLB's reduced accuracy offers better odds for reporting significantly different locations.

I'm sure the operators at the ground stations understand the 100 meter quantization. A jump from one location "bin" to a adjacent "bin" is no cause for alarm. The 100 meter accuracy is still far better than the pre-GPS 2 Km accuracy by doppler shift location. (The doppler location (within its accuracy) can still used to verify the GPS location.)

Anyway, all academic because of the conflicting accounts of what she used to signal for help. Both devices have drawbacks that could have failed her on that terrible day.

I personally find the reports that she used a PLB more credible, but as you note neither is 100% and both are affected by how they are used.

Doug

 

[Trail Boss]

... I believe both use the most recent GPS location. (Nothing else makes much sense--an earlier location is just as likely to be inaccurate as the latest one and the victim might move. Also multiple locations would be a clue to the SAR folks that accuracy might be a problem.)

Ditto. I brought it up because the CatskillMountaineer article implied the SPOT mishandled the situation compared to a PLB. The article states the SPOT's eleven SOS transmissions, with differing geolocations, misled the SAR team. They implied the PLB would not do this. They're intimating the PLB operates differently and would only transmit a single, unwavering geolocation. That's either a revelation about PLBs or just BS. I lean towards the latter.


I haven't read this book, but according to posts here, the author states Matrosova used a PLB. Is there anything in the book that explains why others sources (like CatskillMountaineer who claim it was a SPOT) are wrong?

 

[egilbe]

Ty interviewed Fahoodi and the members of the rescue team. I tend to give more weight to his account, since it corroborates what I previously read she had used 2 years ago. The bouncing signal locations were attributed to her putting the PLB back in her pack. Also, her model of PLB wasn't rated for the extreme temps experienced on that day. No SPOT is ever referenced in the book or any other previous reports that I have read about the accident. It could just be a case of a lazy jounalist not fact checking and getting the terms of the PLB and SPOT mixed up, thinking they are one and the same.

 

[Trail Boss]

@egilbe

Thanks!

I agree that some articles have demonstrated "lazy journalism" and mixed up PLBs and SPOTs. In CatskillMountaineer's case, they don't appear to be accidentally transposing the devices but go out of their way to prove it was a SPOT.

Please note: There were a number of reports that a PLB was recovered. But, after a long investigation, it was determined that only a SPOT was involved. The final SAR report clearly stated that they only recovered a SPOT. PLB's can handle actual temperatures down to -40F. PLB's can only activated ONCE. We know that she activated the SPOT 11 times. It should be noted that the PLB only sends one signal. The SPOT is capable of transmitting a signal down to -22F. It was colder then -22F that night.

"The final SAR report ... they only recovered a SPOT" and "... she activated the SPOT 11 times". If it's not in Ty's book, where did they get this stuff? One of these two parties doesn't have the story straight.

Is the "final SAR report" available online?

 

[egilbe]

I think the confusion was on the updates they were getting from the US Air Force. They would check the location, see that it moved and update the incident commander on the ground. There were ~ 11 updates during the search. Two.of them were in the same location as the original, a couple were in King's Ravine, one was down around Valley Way, below treeline. More than likely, Kate died very shortly after activating the signal. It may be that the final SAR report was written by someone who used SPOT and PLB interchangeably. I don't have that information, but it sounds to me, that's more than likely what happened. Kate certainly wasn't running around activating her SPOT just to confuse potential rescuers.

From the book of the inventory of her pack contents, it appears she wasn't eating or staying hydrated. Her body ran out of fuel and on pure will alone managed to somehow activate the PLB so her body could be located.

On another website I called her foolhardy, but after reading Ty's book, I think that was unfair. She didn't know what she didn't know. Her personality drove her to overcome obstacles. Low temps and high winds were just another obstacle to overcome, and she failed, for the first time in her life, apparently.

 

[akafuzzjones]

From page 16 of the book:

Inmarsat Satelitte Phone
ACR ResQLink 375 Personal Locator Beacon

First ping was near where she was found. The unit was found inside the pack with the antenna folded up. The resulting mis-pings are believed to be the result of the unit not being kept in optimal operating position.

 

[TCD]

Of course one can only speculate, but given her small size and the extremely high winds, her body may have been being "rag-dolled" around by the wind for a while. Maybe not blown any significant distance, but maybe tumbling around and being reoriented frequently. Doing that to the PLB could certainly contribute to the appearance of "bouncing locations."

 

[Tom_Murphy]

I apologize if I state this poorly, but...

The misreported location did allow the SAR Team to avoid the direct decision of whether or not to attempt to reach the Star Lake location at the night during the height of the storm. If that Star Lake location had been their only information, the SAR Team would have been forced, by her actions, to make a very difficult decision at the treeline.

That is not to belittle what the SAR Team did accomplish. I can't imagine going into that ravine on that night in those condtions. As I read that part of the story, I was "happy?" " grateful?" they used the rule of four and had two others on standby at their jump off point ready to assist them.

 

[egilbe]

I believe the only reason they went into the ravine was because of the misreported location. Its also stated in the book that under no circumstances was anyone going above treeline.

 

[akafuzzjones]

I believe the only reason they went into the ravine was because of the misreported location. Its also stated in the book that under no circumstances was anyone going above treeline.

Correct - no plans to go above treeline that first night.

 

[ChrisB]

What Counts

Correct - no plans to go above treeline that first night.

All this discussion about the accuracy and reliability of location devices ignores one critically important factor: You must be able to survive on your own until rescuers arrive.

Even if her device operated flawlessly, providing consistently accurate position indicators, there is no way (given what she carried) she could have successfully survived for 12-20 hours hunkered down awaiting a rescue.

And that is the fatal trade off of the fast and light approach: If nothing goes wrong you are a hero. When something bad happens you can quickly become a statistic.

cb

 

[Tom_Murphy]

Correct - no plans to go above treeline that first night.

I may have to work on my reading comprehension. I remember the book passage stating that there was no way the USFS was going to ask a SAR Team to enter King Ravine that night.

But I thought the decision to go above treeline was left to the SAR Team to decide based on the conditions when they got up there and that they were not forced to make it since they decide to check the second location instead.

 

[TJsName]

When something bad happens you can quickly become a statistic.

The denominator isn't so bad, but it's the numerator you have to look out for.

 

[akafuzzjones]

I may have to work on my reading comprehension. I remember the book passage stating that there was no way the USFS was going to ask a SAR Team to enter King Ravine that night.

But I thought the decision to go above treeline was left to the SAR Team to decide based on the conditions when they got up there and that they were not forced to make it since they decide to check the second location instead.

The decision to not enter the ravine seemed to have been made before the MSR team left (121) and the decision to go above treeline was going to be made along the route. When MSR met with F&G on Valley Way they decided they weren’t going above treeline. (128)

 

[sierra]

Of course one can only speculate, but given her small size and the extremely high winds, her body may have been being "rag-dolled" around by the wind for a while. Maybe not blown any significant distance, but maybe tumbling around and being reoriented frequently. Doing that to the PLB could certainly contribute to the appearance of "bouncing locations."

Now, that's really just adding pure speculation, which has limited value at best. The device has an antenna that should be "up", it was down and in her pack. That makes more sense then, her being blown around, imo.

 

[akafuzzjones]

"The final SAR report ... they only recovered a SPOT" and "... she activated the SPOT 11 times". If it's not in Ty's book, where did they get this stuff? One of these two parties doesn't have the story straight.

Is the "final SAR report" available online?

I confirmed what I wrote earlier and what is in the book with Ty last night. It was the ResQLink 375. It is what’s listed in the SAR report (which he saw) and the photo inventory of what was in her pack. There were a few “spot” references and he has no idea where they got that information since no one he interviewed ever said it was a spot.

 

[akafuzzjones]

Of course one can only speculate, but given her small size and the extremely high winds, her body may have been being "rag-dolled" around by the wind for a while. Maybe not blown any significant distance, but maybe tumbling around and being reoriented frequently. Doing that to the PLB could certainly contribute to the appearance of "bouncing locations."

The unit was found in her pack with the antenna folded. It would appear that she initially signaled using it correctly and then closed it up and put it back in her pack. While it’s quote possible her pack was moved by the wind it’s more likely the mid-pings were the result of the folded antenna and unit not facing skyward. The unit was tested afterwards (obviously not in the same conditions) and it worked perfectly.