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Re: Story of missing hiker in Joshua Tree NP

PostPosted: Thu May 19, 2016 10:52 pm
by adamghost
I have been up to the north side of SWC a few times. The one spot where there's known reception around 10.6 has been pretty well covered; I've been up there and so has Tom a few times.

One thing I have to say about the north slope of SWC: the climb up SUCKS. It's really bad from almost any angle. Very steep and tough. It's just hard to imagine a non-able bodied hiker making it too far up the slopes. The last trip up that way I found a back way in that wasn't too bad, but one of the things I was thinking at that time is that Bill might have found a viable entry point to the north side of SWC at the eastern mouth by Quail Wash. It seemed to both Tom and myself (the latter from a distance) that it might have been easier.

I did finally get to take a look at that approach on this last trip and it wasn't too bad. Could Bill have gone up that way? Yes. But.

I am really sympathetic to the idea that it's the most likely place to look simply because it hasn't been looked at much (and you're absolutely right, if he is up there there's an almost endless number of places he could be), and it's about the right place.

The problem goes back to the whole, you're looking at the topography, trying to work yourself up to look at it and you go "there's just no way." This is why I ruled out the badlands west of Upper Covington after I tried multiple times to get in there. Past a certain point, there are just too many obstacles even for an able-bodied person. (Tom did get in, and cursed me by name for advancing this theory when he did)

So...yeah. The slopes of the north side of SWC are just like that. I did climb up to the top from SWC once. I made it. It was long and fricking steep. I will allow that we found an abandoned Snapple bottle part way up, so someone else did it at some point. But it's just hard to credit for a guy in Bill's position. I can accept he might have made it up a little way, and I think that's how Tom sees it.

The mountain lion theory makes a lot of sense BUT - if Bill is taken out by a mountain lion does he get dragged out of the search area in such a way that no trace is left, including his pack, etc.? That's a little harder to credit. And remember - the same mountain lion has to drag poor Bill up the same steep slope.

None of this is to say that he couldn't be there. I'm just speaking from the vantage point of the guy who's looked at some of these spots and kind of gone "nah." And by saying that, understand I have to decide how to expend my time and energy. There is a motivation factor, and this isn't a grid search. If it just doesn't look or seem plausible to you, it's hard to go charging in there.

These are all great suggestions though, keep 'em coming. I'm liking the east side of Quail Wash as the first place to look though. I may have a window to do it as soon as next week.

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Fri Oct 14, 2016 6:06 am
by RichardK

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Thu Feb 09, 2017 10:38 pm
by Ric Capucho
Otherhand has a new trip report up on his site...

http://www.otherhand.org/home-page/search-and-rescue/searching-for-bill-ewasko/jt86-282017/

Still no Bill...

Ric

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Mon Feb 13, 2017 3:46 pm
by bretpct
Hello all,

I’ve lurked here for a while following this search. I’ve made a few trips out to JTNP myself, mostly just rehashing already searched areas, familiarizing myself with the area. Last weekend I decided to test out one of my own theories, that Bill was closer to Serin tower than expected. I created my own cell coverage map using an online RF coverage calculator thingy (which matched up with existing maps pretty well) and noticed a small small zone of coverage just shy of a 9.6 mile radius from Serin.

I hiked out there to check it out, and found some very steep terrain, much more so than the topo map let on.
Image

I was exploring one of the drainages when I unexpectedly came across a piece of a plastic bottle at 34.0505, -116.2831. This was very surprising to me as I’ve never found anything like this while hiking in this hill system besides mylar balloons.

(Can you spot it?)
Image

Image

I followed the wash upstream to a 20’ dry waterfall, then downstream toward the desert floor for about 1/2 mile.
Image

I then picked up the wash from the top of the waterfall and followed it upstream to a bowl, never finding anything else.

The markings on the bottle indicate is type 1 PETE plastic. The numbers, which are hard to photograph but quite easy to read say “6337 10”. It’s hard to find any information on how bottle forms are coded, so I as of yet haven’t been able to find any further information from those numbers. If “337” is a Julian number, that corresponds to December 3rd, and if “10” is 2010, that would post date Bill’s disappearance.

To me, it looks like a water bottle, probably about 500-1000mL in volume. The plastic itself seems fairly thick, unlike the newer crinkly bottles. The closest thing I’ve found in supermarkets are Evian bottles.

Image
Gold is 9.6 mile radius. Black is 10.6 mile radius

I don’t know if finding a piece of plastic bottle warranted a whole post about it, but I figure every little bit helps.

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Mon Feb 13, 2017 10:41 pm
by OtherHand
My guess is that it's debris from local hikers of some years ago. The area northwesterly of there, Nola Cove (?) used to be a private inholding in the park with a number of cabins. All appear to be now gone with some foundations still visible on aerials. Still, you picked about as remote a spot to poke around in as possible. My hat's off to you there. BTW, the plateau-like area at the southwest corner of your map is a wonderfully scenic spot that's little visited. Pretty easy to get to from lower Covington, once the annoying climb is out of the way.

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Tue Feb 14, 2017 10:38 am
by Perry
Re:
http://www.otherhand.org/home-page/sear ... 86-282017/

Maybe the algorithm used an average processor time and there's a lot of variation ("jitter") in latency?
https://en.wikipedia.org/wiki/Interrupt_latency

This could potentially put Bill's cell phone farther away. A variation of only +/- 1 microsecond means +/- 0.186 miles of error. +/- 10 microseconds means +/- 1.86 miles.

This may be a moot point if the ping happened when the phone was inside a moving vehicle.

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Tue Feb 14, 2017 1:35 pm
by Ric Capucho
Perry wrote:Re:
http://www.otherhand.org/home-page/sear ... 86-282017/

Maybe the algorithm used an average processor time and there's a lot of variation ("jitter") in latency?
https://en.wikipedia.org/wiki/Interrupt_latency

This could potentially put Bill's cell phone farther away. A variation of only +/- 1 microsecond means +/- 0.186 miles of error. +/- 10 microseconds means +/- 1.86 miles.

This may be a moot point if the ping happened when the phone was inside a moving vehicle.


That's the counter-intuitive nature of "latency".... longer always means closer on terms of distance.

Ric

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Wed Feb 15, 2017 11:15 am
by Perry
As an example, suppose the cell phone microprocessor or microcontroller has a minimum time of 4 microseconds and a maximum time of 8 microseconds, depending on what tasks are happening inside the phone. (I'm totally making up numbers here.) If the tower uses 4 microseconds in calculations, then the calculated distance would be a maximum and the real distance could not be farther away. But if the tower algorithm uses the average value of 6 microseconds, then the real distance could be closer or farther than the calculated distance.

A computer science expert might have something more to say about this. It would probably help to know what type of phone Bill was using and the chips inside. And the tower itself could also have variation in timing. The tower was undoubtedly doing many tasks simultaneously. We don't know how many tasks, how it deals with the buffers and interrupts, and how the algorithm accounts for this. I wouldn't assume it's "very accurate" just because a representative of the company says so.

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Wed Feb 15, 2017 12:01 pm
by bretpct
OtherHand wrote:My guess is that it's debris from local hikers of some years ago. The area northwesterly of there, Nola Cove (?) used to be a private inholding in the park with a number of cabins. All appear to be now gone with some foundations still visible on aerials. Still, you picked about as remote a spot to poke around in as possible. My hat's off to you there. BTW, the plateau-like area at the southwest corner of your map is a wonderfully scenic spot that's little visited. Pretty easy to get to from lower Covington, once the annoying climb is out of the way.


It was indeed pretty quiet over there. When I got to the area where the bottle was, I thought there would be no reason for Bill or anyone to visit this area, apart from mountain lions, evidenced by some bighorn remains.

From that plateau, the clouds let up for a bit and I got a wonderful view of Jacinto and Gorgonio. My iphone wide-angle lens doesn't do it justice.

Image

Re: Story of missing hiker in Joshua Tree NP

PostPosted: Thu Feb 16, 2017 4:15 pm
by RichardK
With respect to the cell phone distance accuracy, recall the field test reported in Current Bill Ewasko thoughts, January 2013. Verizon's system is surprisingly accurate. Remember that Bill was using an old style flip phone that lacked the all of the crap that eats up processing power in a smartphone. The flip phones didn't have a whole lot to do other than send and receive cell signals. Hence, low latency.

Part of the answer came from Mike Melson, cell phone guru. Recently Mike shared with me some cell phone testing he had performed in the lower Covington Flat area. It’s an area about 10 miles from the Serin Drive cell tower with marginal to non-existent cell signal coverage. Mike was using an Android phone with an app that told him when he was connected to the Serin Drive tower (just another damn thing I can’t do with my iPhone!) What he did was send text messages while noting his precise lat/long position and the time. Later, he was able to obtain from Verizon the distances from the tower Verizon’s system recorded for his transmissions. The bottom line was that the distances Verizon recorded were very close to the actual positions, usually less than a few tenths of a mile off. Most of the time the errors were on the near side with the system thinking he was ever so slightly closer to the tower. This was probably due to reflections off higher rock faces increasing the path length. But overall, Verizon’s path length measurements were very close, strongly suggesting their 10.6 mile measurement for Bill’s ping was in fact accurate. Validation of Verizon’s system also implies that any true distance for Bill beyond, say 11.1 miles (within 10% of 10.6 miles to quote the Verizon tech) would be a physical impossibility. This excludes all areas southerly of Smith Water Canyon, such as Quail Mountain and Lang Canyon. You know, those areas we spent so much time on.