Stranded for 49 days

Posted by: dougwalkabout

Stranded for 49 days - 05/07/11 04:07 PM

A strange story about a Canadian couple who vanished 7 weeks ago and turned up in a remote part of Nevada:

http://www.theglobeandmail.com/news/nati...article2013877/

"Raymond Chretien said his mother told him they were sightseeing on back roads when their 2000 Chevrolet Astro van got stuck in mud. Three days later, Albert Chretien, 59 set out on foot to look for help, and never returned."

The wife stayed with the van and was eventually found alive by hunters. The search for her husband is on, but a happy ending seems unlikely.
Posted by: MDinana

Re: Stranded for 49 days - 05/07/11 04:42 PM

That's incredible.

One has to wonder, being from Canada, why they hadn't prepped just a little better. Unless they had 20lbs of trail mix...
Posted by: bacpacjac

Re: Stranded for 49 days - 05/07/11 04:48 PM

I've been following this one too, Doug, wondering what happened to them. There was a similar sounding story just a few weeks before this couple disappeared. That one ended in foul play. I'm glad that wasn't the case this time, but it doesn't sound hopeful for the husband.
Posted by: comms

Re: Stranded for 49 days - 05/07/11 07:01 PM

Wow. Add Costco sized trail mix to travel kit. Add a PLB
Posted by: dougwalkabout

Re: Stranded for 49 days - 05/07/11 08:16 PM

A few more details are coming in. Nobody was searching for them in Nevada (their ultimate destination), as the last place they were seen was in Oregon.

http://www.cbc.ca/news/canada/story/2011/05/06/penticton-couple-woman-found.html

"Police said she told them they became stuck on the logging road March 21 and she had been there since then, surviving on water alone."

http://www.cbc.ca/news/canada/story/2011/05/06/penticton-couple-woman-found.html

"On Saturday, teams began searching in Nevada's Elko and Owyhee counties. The Chretiens' van was found near the Nevada portion of the Bruneau River and the town of Rowland.
Officials said weather over the past month in that area has included snow, rain and chilly temperatures, and a road near the Bruneau River saw a large landslide in early April."

Also, there are hints that GPS may have been a factor. Apparently they had a car GPS, which the husband took with him when he went for help. Some commenters on the news stories indicate GPS in the area directed them to turn onto this logging road, but they ignored its 'advice.'
Posted by: bacpacjac

Re: Stranded for 49 days - 05/07/11 11:43 PM

I hate to criticize but this is a great learning opportunity. If only more people would pay attention. I've already heard someone write this off to the couple being "old people".

Growing up, my parents and grsndparents always advocated that we travel to "survive not arrive." Any number of things can happen between point A and point B. Especially on a long trip in unfamiliar remote territory, it would seem prudent to take extra supplies. Unfortunately, many people don't get very deep into their "What's the worst that could happen?" thinking.
Posted by: Susan

Re: Stranded for 49 days - 05/08/11 04:19 AM

This is another good example of multiple poor decisions leading to disaster. It's the Kim family all over again.

It really does help to be a little smarter than your GPS.

Penticton, B.C. is hardly a metropolis, they live almost in what could be called 'the sticks', with a lot of wilderness around them, with reasonably cold and warm/dry seasons, not dissimilar to the country they got stuck in.

They followed their GPS onto a logging road. I've been on lots of logging roads, and it's hard to mistake them, really.

One news article said, "...For two days they were getting stuck and unstuck in their vehicle over and over again ..."

So, naturally, they continued? It didn't occur to them that something was wrong and to turn around and go back the way they had come to the highway or interstate? WHY?

There's no mention of building a signal fire.

If he was walking back to the highway, it couldn't have been that far away (the way they kept getting stuck), and if he had followed their car tracks back, they should have found him by now. And if he had walked the 9 miles toward the highway like the hunters did, he should have gotten cell phone coverage, too. Like Kim, did he decide to take a 'shortcut' cross country? In rough country, in bad weather?

I wonder if Rita learned anything from this little outing?

1. If the road gets that rough, turn around and go back the way you came, don't wait until you get stuck or the car breaks down.
2. Stay with the vehicle and build a signal fire.
3. If you decide to leave the vehicle, follow your car tracks back the way you came.
4. Don't try to take shortcuts.
5. When all else fails, THINK!

I'm sorry it happened, but I'm not surprised. They don't sound very smart.

Sue
Posted by: Richlacal

Re: Stranded for 49 days - 05/08/11 04:38 AM

It is Also a Possibility the husband met up with Canis Lupus-(Wolves),They have been seen in Packs in Southern Idaho,& Western Utah as of late,where they have not been for 80+ yrs otherwise!
Posted by: roberttheiii

Re: Stranded for 49 days - 05/08/11 12:51 PM

Cheers to the thought of following your tracks out. No cross country shortcut is worth it in a case such as this.
Posted by: BruceZed

Re: Stranded for 49 days - 05/08/11 10:06 PM

What I found so fascinating is that she basically FASTED for nearly the entire time, as the trail mix could not have last more than a few days. Normally we work on the assumption that you can last 30-40 days without food (i.e. fasting) if you consume 3-4 L of water. If you weight more (i.e. more fat), you can last longer in a survival situation. Colder weather will lessen survival times along with poor weather, but staying in a vehicle and drinking water every day saved her life. She last 49 days which is fantastic to see. She most likely suffered muscle loss and perhaps organ damage as she was out longer that the 30 or so days which is safe on our body.

The biggest psychological barrier to survival she faced is that the first 4 to 5 days when she was hungry and her energy levels were low would have been hard. Hunger subsides in time and energy levels come back up as well. After that she just need to keep mentally busy and not worry about her husband who wander off into the desert.

Staying put and waiting rescue normally is the best thing to do. In this case despite having no real search in the area she was still found by passers-by before she starved to death.
Posted by: stargazer

Re: Stranded for 49 days - 05/09/11 09:46 AM

This is indeed a tragedy.

The area they found Mrs. Chretien in is extremely remote and very inhospitable, brutal even. Going into this area requires extra food, extra water, clothing, shelter, a way to maintain a vehicle (gas), etc. and that is on a good day in the middle of summer. I have been in this area several times and can honestly say it is either 4-wheeler or 4x4 area at times. Horseback helps too. Though described as a logging road, the road is best traveled without difficulty from mid-May (sometimes early June) to when the first snow flies usually in in late September, or mid-October. The elevation is between 5,000' and 7,000' (1524m to 2132m)

Rowland is not really a town, it is a ghost town and a summer ranch area. The nearest town from where they were found according to the GPS is 16.2 miles away (Mountain City, NV along State Route 225) and following any kind of roads would take you over 2 hours to get there. The nearest clinic is in Owyhee, NV and no doubt would have to transfer her to more definitive in Boise, ID or Elko, NV. (She was flown to Twin Falls because it's closer in air miles) Overnight lows is probably going to be in the teens and may reach the forties in the daytime. Add rain, snow and wind and your chances of survival is very low. Obviously she survived, which is good, but not saying what he will be like. Let's not forget wolves (possible) coyotes, mountain lions, etc.

I agree if the road gets rough then turn around.
I doubt a signal fire would have done any good (literally no one to see it dense forest, terrain, etc.), but a fire for warmth would depend on dry material and an ability to gather it.
The rescuers drove for 9 miles to get a cell phone signal. In this area this is not uncommon usually it's more. A PLB, HAM Radio, or Satellite phone would have made the difference.
Know and understand your GPS and its limitations.
Sue is right to not take shortcuts. You'll become lost very easily.
Walking back to the highway (pavement)would take considerable time. NV State Route 225 is the only paved road in the area and walking means going through harsh terrain, streams, gully's, canyons and you get the picture (use mapper.acme.com - topo feature)(usual disclaimer) and you'll see what I am talking about.

This is a very pretty area to visit and inside of an hour you can literally go from Canyon-lands to high desert plateau and into forested mountains. The whole area has been designated wilderness and what isn't wilderness is National Forest and even the Elko County badlands. But traveling here means taking some responsibility.

Take care,

Stargazer



Posted by: dougwalkabout

Re: Stranded for 49 days - 05/09/11 02:17 PM

Another update:

http://www.theglobeandmail.com/news/nati...article2014245/

The search for Mr. Chretien is still considered a rescue not a recovery operation, though sadly the odds are not in favour.

The physician treating Ms. Chretien makes some interesting comments about her physical condition and the psychological/spiritual component of her survival.
Posted by: Phaedrus

Re: Stranded for 49 days - 05/09/11 04:59 PM

I wonder what the basis is for considering it a rescue? obviously I hope he staggers into a gas station, ragged and unkempt but otherwise none the worse for wear- but how likely it that at this point? He seems to have left the food, and probably had little useful gear (eg. fire, shelter, water). She survived because she was near water, had minimal food and had the van for shelter as well as a suitcase full of clothes. He has been exposed to the elements for a month and a half.

Again, I hope he's found alive but stories like this really do serve as a wake up call. It's shocking how unprepared people sometimes are. But then again, I've taken winter trips on well traveled routes with probably much less safety gear than I should have. I'm definitely gonna have to go thru my truck bag again and see what I need to add or replace.
Posted by: Susan

Re: Stranded for 49 days - 05/09/11 06:46 PM

> "...I've taken winter trips on well traveled routes with probably much less safety gear than I should have."

Of course, everyone has! The difference between an interesting trip and big trouble is the decisions you make along the way.

The thought processes of some people is often totally beyond my understanding.

I have traveled (with just a dog) from California to Maine, and zigzagged back and forth across the Continental Divide from Mexico to Canada, and gone to many isolated ghost towns. The only time I really got into real trouble was on a well-used, two-lane state highway in Utah, when I was run off the road by an oncoming car that was passing a pickup/trailer on a curve, and I nearly rolled, blowing a tire and breaking a shock absorber.

Sometimes I've been on a road so rough (with definite signs to my destination) that I've stopped the vehicle and walked ahead to check on the further conditions. Sometimes I gave up and just turned around and returned to the highway. Sometimes I continued at the speed of a slow walk. But I never got stuck and never damaged the car.

I've walked trails with the dog and had the dog stop me a couple of times, her ears back and tail tucked. We turned around and headed back to camp, awareness on max, head swiveling constantly. Never saw the danger (large predator, I'm assuming), but knew for certain that it was there, somewhere.

I've driven on gravel roads and gotten onto the wrong side road because a sign was down. When the side road was good, I went a good long way before I realized my mistake. Then I turned around and went back.

NEVER, in all my travels, have I tried to take a shortcut when I was lost, on foot or driving. NOT EVER! That is just begging for trouble, esp when no one even knew what state I was in.

Roads and trails are always the easiest paths, and for a good reason! You can make far better time on a winding gravel/dirt road than you can by attempting to go across country, wearing yourself out by climbing down and up, setting yourself up for hypothermia by crossing streams, taking the chance of injuring yourself in rough country.

As has been said here before, most personal disasters are preceded by people making repeated stupid decisions.

Stay alive. Try thinking.

Sue
Posted by: hikermor

Re: Stranded for 49 days - 05/09/11 07:15 PM

SAR people are incredibly optimistic, at least in public.
Posted by: chaosmagnet

Re: Stranded for 49 days - 05/09/11 07:57 PM

Originally Posted By: Susan
NEVER, in all my travels, have I tried to take a shortcut when I was lost, on foot or driving. NOT EVER! That is just begging for trouble, esp when no one even knew what state I was in.


This concept ought to be on the written test for a driver's license in every state.
Posted by: dougwalkabout

Re: Stranded for 49 days - 05/10/11 03:14 AM

Originally Posted By: hikermor
SAR people are incredibly optimistic, at least in public.


That's a fair comment. From what I've read, they are leaving open the possibility that he found natural shelter or a hunting cabin. Outside of that, it's grim business.

I am somewhat taken aback by a few of the harsh comments in other posts. Smart people can make mistakes, and lack of experience combined with worry and fatigue can lead them to compound those mistakes with disastrous results. It can happen to us too, which is why we plan to mitigate the effects of unexpected events and try to learn from others' experiences. Anyone who hasn't been "out of their element" a time or two raise your hand.
Posted by: Phaedrus

Re: Stranded for 49 days - 05/10/11 03:45 AM

Hopefully I didn't come across as harsh. I hope to heck he's alive. And yeah, I guess he could've happened upon a hunting cabin or something. But at this point no one has seen him in a month and a half.

I've been contemplating it for a few months but this particular story has galvanized my resolve to get a McMurdo Fast Find 210. I'll have to start setting aside a few bucks each payday for one. From what I've been able to find in the online literature it's a solid unit. If the couple had had a PLB, by now they'd just have a mildly embarrassing story to tell their friends and family.
Posted by: Susan

Re: Stranded for 49 days - 05/10/11 03:47 AM

Death is a harsh business. I would like to put mine off as long as possible.

There's an important trick to being 'out of your element', and that's being smart enough to recognize it once you're there.

Different people handle it different ways. Some stop and reconsider all the possibilities and their options. Some freeze and their brain shifts into neutral. Some don't seem to recognize real trouble, not only when they enter it, but even when they're well into it. And there are always, the 'nothing will happen to me' folks who have apparently watched too much TV and barely have a nodding acquaintance with reality.

Doug, what do you think when you see a young man racing down a crowded highway at over 100 mph (161 kph)? Do you think he's an idiot, and hope he doesn't kill someone? Are you being harsh, or are you being realistic?

This couple made so many poor decisions that it occurred to me that one/both of them were considering suicide or murder. It wasn't JUST that they went sightseeing in iffy weather, and it wasn't JUST that they did it with no thought to being prepared if something went wrong, and it wasn't JUST that when the road deteriorated that they continued instead of turning back, and it wasn't JUST that he decided to walk away, and it wasn't JUST that he probably headed cross-country. It was a combination of a bunch of bad decisions. If Al C. had not done just ONE of those things, it could have been a happy ending. ONE THING!

If my friends who know me well read in the paper that I had done all those things, they would have all agreed that I had apparently lost my mind!

What's really discouraging is that we all know people who would have done all those same things!

Sue
Posted by: hikermor

Re: Stranded for 49 days - 05/10/11 09:42 AM

A string of five or six really bad decisions is quite typical of many search and rescue scenarios. People who manage to get about a third of their choices right usually avoid the clutches of SAR, or at least trigger operations that are less than epic and do not generate headlines.

To some extent I base this statement on personal experience, where I made some really world class dumb moves, but managed to stay under the radar and reach home safely by making offsetting good calls (like carrying most of the Ten Essentials, and putting a shovel in the car). Dumb luck also plays a part..
Posted by: dougwalkabout

Re: Stranded for 49 days - 05/11/11 01:06 AM

Everyone is entitled to their perspective. Personally, I shy away from categorizing people based on their particular mix of strengths vs. infirmities. As time goes by, I find I have an ample supply of each. (Also an ample supply of dumb luck, thank goodness.)
Posted by: Richlacal

Re: Stranded for 49 days - 05/12/11 03:58 AM

Another possibility is Mine shafts/vents,There are Literally 1000's of them in that particular area,The whole state of Nevada is Heavily mined,& Nevada has more Mountain ranges than any other state in the union,of which makes SAR Extremely difficult!
Posted by: Aussie

Re: Stranded for 49 days - 05/12/11 05:42 AM

Some interesting analysis going on here. I can speak from some personal experiences (embarrassingly), and the thing about this story (as with many other tragedies) is that from our arm chairs it is easy to spot where things have gone wrong, and easy to see what “should have” been done. I’m not criticising anyone, I think this is a very useful exercise

…. Just hang on a moment while I adjust my cushion …. now that’s better …

When you are actually in the situation, you often may not realize the first few mistake (eg inappropriate track, lack of food etc), and by the time the alarm bells start to ring you are already in a “situation”. At that point you need to be calm enough to make a decision about what to do, and depending on the information available, and your own experiences and personality you will either make, what turns out to be, a good or bad decision.

At the time (in this case probably cold and wet, tired and hungry, angry for getting to this point) you make the best decision available, and it will not be until later that you either laugh it off over dinner with friends, or make the headlines of the newspapers !
Posted by: Byrd_Huntr

Re: Stranded for 49 days - 05/12/11 11:49 AM

Originally Posted By: Aussie
Some interesting analysis going on here. I can speak from some personal experiences (embarrassingly), and the thing about this story (as with many other tragedies) is that from our arm chairs it is easy to spot where things have gone wrong, and easy to see what “should have” been done. I’m not criticising anyone, I think this is a very useful exercise

…. Just hang on a moment while I adjust my cushion …. now that’s better …

When you are actually in the situation, you often may not realize the first few mistake (eg inappropriate track, lack of food etc), and by the time the alarm bells start to ring you are already in a “situation”. At that point you need to be calm enough to make a decision about what to do, and depending on the information available, and your own experiences and personality you will either make, what turns out to be, a good or bad decision.

At the time (in this case probably cold and wet, tired and hungry, angry for getting to this point) you make the best decision available, and it will not be until later that you either laugh it off over dinner with friends, or make the headlines of the newspapers !




I think you hit the nail on the head.

Depending on circumstances, almost any quick decision could turn out to be wrong. Even some considered decisions can turn sour...after all, there is a 50% divorce rate. This story calls into focus the need to always have a few survival essentials with you, especially knowledge.

As Cody Lundin put it; "Knowledge is power and it's extremely lightweight".
Posted by: Andy

Re: Stranded for 49 days - 05/13/11 03:44 PM

The authorities in Nevada are getting concerned about travelers relying too much on GPS devices. From MSNBC.

Had that happen to me once in NH in early spring when my GPS sent me on a back road with 12 inches of slush. Fortuneatly I was driving my AWD Subaru and got through with just white knuckles. The main road I turned off of was clear and dry.
Posted by: UncleGoo

Re: Stranded for 49 days - 05/13/11 03:59 PM

Originally Posted By: Andy
The authorities in Nevada are getting concerned about travelers relying too much on GPS devices. From MSNBC.

Had that happen to me once in NH in early spring when my GPS sent me on a back road with 12 inches of slush. Fortuneatly I was driving my AWD Subaru and got through with just white knuckles. The main road I turned off of was clear and dry.


GPS: In 2007 we had two ESL drivers for a discount furniture warehouse drive a 28foot box truck--a mile and a half--down an abandoned road that was built by the Civilian Conservation Corps in the 1930s. They got stuck (I know: you saw that coming), and it took six hours with a Kenworth wrecker to get them out.
All us gringoes could think, was that must have looked like a good road, in the old country...
Posted by: LazyJoe

Re: Stranded for 49 days - 05/14/11 06:36 PM

follow-up story

http://www.oregonlive.com/pacific-northw...infallible.html
Posted by: Susan

Re: Stranded for 49 days - 05/14/11 08:31 PM

And Chretien did it at night, too... *rolly eyes*

They still haven't found him.

911 tape highlights lost Canadian woman's plight

You know, this would be the perfect way to murder someone without fear of retribution. People would just think you're really stupid. Murder by GPS.

Oh, never mind that idea for a murder mystery, it's already been done: Murder by GPS

Sue
Posted by: dougwalkabout

Re: Stranded for 49 days - 05/15/11 05:36 PM

Originally Posted By: LazyJoe


Thanks for the link. Some very interesting details in there.

So he did this at night, while his wife was asleep? That hadn't been reported before. It begs some new questions about the string of bad/naive decisions. I wonder how much fatigue and get-there-itis played into this. I also wonder if a second pair of eyes may have influenced the decision-making process -- to say "I don't like this road" or notice that cell service had dropped out.

Another thought: I wonder if driving this road in daylight might have provided more cues to set off "the little voice in the back of your head that tells you something isn't quite right." The condition and maintenance of the road, the increasingly rough terrain, the lack of other vehicle tracks, the fact that (IIRC) they were gaining a lot of elevation -- these things are much less obvious when you're in unfamiliar territory and all you see is what's in your headlights.
Posted by: Susan

Re: Stranded for 49 days - 05/15/11 09:58 PM

She didn't sleep through a rough road and getting stuck multiple times, I'll bet money on that. Either this guy is unbelievably stupid and incredibly stubborn, or something else is going on here.

"Chretien's wife, Rita , 56, meticulously recorded his planned GPS route in her journal, including the turns he'd be forced to make negotiating the difficult terrain of the mountains and canyons, Prall said." From here

Chretien and his GPS, working together, get themselves into a real mess. After thinking about it for three days, he decides to follow his ever-trusty GPS AGAIN. And his plan was to go cross-country, rather than just walking out the way they came in. If the road would accept a 2WD vehicle, a man could walk it.

"'His intention was not to deviate' from the GPS course and to stay on U.S. Forest Service roads all the way to Mountain City, Nev."

So why haven't they found him?

Something is very strange here, veering into the Twilight Zone. I wonder if anyone has checked to see if he showed up in Las Vegas...?

Sue
Posted by: bacpacjac

Re: Stranded for 49 days - 05/15/11 10:13 PM

Originally Posted By: Susan


Chretien and his GPS, working together, get themselves into a real mess. After thinking about it for three days, he decides to follow his ever-trusty GPS AGAIN. And his plan was to go cross-country, rather than just walking out the way they came
Sue


That's bugging me too, Sue. That and the fact that the rescuers are apparently using the exact same model of GPS to try to re-trace his steps.
Posted by: Aussie

Re: Stranded for 49 days - 05/15/11 10:57 PM

Originally Posted By: Susan
You know, this would be the perfect way to murder someone without fear of retribution. People would just think you're really stupid. Murder by GPS.



Originally Posted By: bacpacjac

That's bugging me too, Sue. That and the fact that the rescuers are apparently using the exact same model of GPS to try to re-trace his steps.


... so which one is the victim ?
Posted by: dougwalkabout

Re: Stranded for 49 days - 05/16/11 03:05 AM

I'm not inclined to head in to conspiracy country yet. At least not until they finish the search. I suppose it could be viewed as a perfect storm that's a little too perfect. Time will tell.

- Doug, who foolishly assumes the best in people until they demonstrate otherwise
Posted by: hikermor

Re: Stranded for 49 days - 05/16/11 08:51 AM

I think we can trust the law enforcement agencies to be appropriately suspicious. It is standard to make inquiries about family stability, etc, even when the focus is on the back country search.
Posted by: Outdoor_Quest

Re: Stranded for 49 days - 05/16/11 12:20 PM

The following is a follow up story from the Montreal Gazette.

http://www.montrealgazette.com/news/cana...3822/story.html

Blake

www.outdoorquest.biz
www.outdoorquest.blogspot.com
Posted by: Am_Fear_Liath_Mor

Re: Stranded for 49 days - 05/16/11 01:01 PM

Quote:
She didn't sleep through a rough road and getting stuck multiple times, I'll bet money on that. Either this guy is unbelievably stupid and incredibly stubborn, or something else is going on here.


I would have to go with unbelievably stupid and incredibly stubborn. Many modern Homo Sapiens aren't the sharpest tools in the box when it comes to ignoring the voice giving the directions from the magical navigation box.

As more folks become compliant to systems of politically correct eduction, fashion, business, advertising, technology, communications, consumerism and systems of governance the duller the tools become.


Posted by: quick_joey_small

Re: Stranded for 49 days - 05/16/11 01:26 PM

Reminds me of a comment by an Arnhem survivor:
"In battle if you make 1 or 2 major mistakes; you win.
Make 3 or 4: you lose.
We made about 15".
qjs

>A string of five or six really bad decisions is quite typical of >many search and rescue scenarios. People who manage to get about a >third of their choices right usually avoid the clutches of SAR
Posted by: Russ

Re: Stranded for 49 days - 05/16/11 02:01 PM

I travel with a couple different GPS units, a Garmin Nuvi sits on the dashboard and provides the highway routing, traffic avoidance/optimization and ETA info. I routinely ignore its advice in the local area because I have preferred routes and I like hearing it say "recalculating" smile

The other GPS is a Garmin GPSMAP 60 CSx. It has routing ability but I never use it. It is loaded with terrain maps of the western US in addition to standard highway. It also gives elevation info which for some reason is unavailable on the Nuvi (unlike the GPS V which I used before the Nuvi).

GPS receivers are great for navigation, but you need to know their limitations. I'd never follow the Nuvi offroad.

That said, shortest distance does not equal shortest time; my Nuvi's routing is set for shortest time so it almost always generates a route on highways. (Edit: a Nuvi can be set for shortest distance, but why take the shortest distance if it takes more time??) If it ever put me on a gravel/dirt road, I'd be pulling out the Rand McNally Road Atlas to see where on Earth I was.

I also travel with a PLB.
Posted by: Russ

Re: Stranded for 49 days - 05/16/11 06:17 PM

Disagree . . I'd put money that the GPS in question was dead accurate until its battery finally died . . the operator just didn't know how to use what it was telling him. He didn't know its limitations and he definitely didn't know his own.

RIP
Posted by: Eric

Re: Stranded for 49 days - 05/16/11 09:13 PM

NightHiker,

I'm not sure I understand. I suspect you are saying you often disagree with the suggested routing a Navigation system is providing.

If you are suggesting that a GPS has provided position data that was off by more than its reported accuracy limits (due to satellite geometry) I would be more concerned.

Hopefully you are saying the former and if so that is something that makes sense to me. Too many people don't use their own thoughts and judgement when following directions. A Navigation system, like most suggested or prepackaged routes, is not meant to be used without taking external information and conditions into account. Unfortunately too many people don't understand that so we get stories about cars turning off the highway and into peoples houses or driving down service road instead of continuing on to the highway just ahead.

-Eric
Posted by: hikermor

Re: Stranded for 49 days - 05/16/11 09:23 PM

I have experienced bad locations from GPS, but not so bad that I didn't know where I was. In a fairly deep canyon (and probably less than optimum satellite geometry), the GPS told me I was in the bottom of the canyon, while I, eagle eyed archaeologist that I am, could readily see that I was well up the canyon slope at an obvious bend in the canyon.

You must think when you are navigating. Compasses and maps have their imperfections, as well. Don't trust any tool mindlessly.
Posted by: Susan

Re: Stranded for 49 days - 05/16/11 09:37 PM

Quote:
... so which one is the victim ?


I haven't decided yet. grin grin grin

After all, we only have her story. Maybe she was the one who was driving.

Sue
Posted by: Aussie

Re: Stranded for 49 days - 05/16/11 10:53 PM

Originally Posted By: hikermor
I have experienced bad locations from GPS, but not so bad that I didn't know where I was. In a fairly deep canyon (and probably less than optimum satellite geometry), the GPS told me I was in the bottom of the canyon, while I, eagle eyed archaeologist that I am, could readily see that I was well up the canyon slope at an obvious bend in the canyon.

You must think when you are navigating. Compasses and maps have their imperfections, as well. Don't trust any tool mindlessly.


I had a funny GPS experience about 2 years ago: I drove off the edge of the world ! Yes really !

In case you're wondering, there were no sea monsters, but there is a 100m cliff and a pounding surf which sprays up, onto the top.

I encounterd this when I was heading out to Steep Point, that’s the most Westerly point of the Australian mainland, part of Shark Bay in Western Australia. I’d plotted in a few way points (from home in advance) and was expecting to come to a minor track intersection when suddenly the GPS went blank. No information. No nothing. I did a reset and fiddled for quite a while, but the maps and information just stopped ! Later on I met the local caretaker who laughed and told me than (until recently) none of the GPS manufacturers included Steep Point and even Google maps did not cover it (until a few years back). He and a few of the locals encouraged travellers to report back to Garmin etc to request it be added !

This may seem a bit odd to you people in Europe and North America, but its true ! So if any of you are planning a driving trip down here and want to visit Steep Point: check your GPS !

(Yes I had maps etc as a backup and there’s only really one road (track) so you can’t go too far wrong … unless you try of course).
Posted by: Am_Fear_Liath_Mor

Re: Stranded for 49 days - 05/16/11 11:20 PM

Quote:
I'm not sure I understand. I suspect you are saying you often disagree with the suggested routing a Navigation system is providing.

If you are suggesting that a GPS has provided position data that was off by more than its reported accuracy limits (due to satellite geometry) I would be more concerned.


GPS is most certainly a useful tool, but GPS errors are not understood well enough by most folks to risk their own lives with. Most folks assume you just stick the battery in and punch in your destination and away they go. GPS systems have only really become popular in the mainstream since manufacturers dispensed with the monochrome screens that just showed WGS84 polar co-ordinates with no maps to display and didn't ask for such setup parameters such as a map datum and magnetic/grid/true north deviations or declinations etc.

The relationship between the GPS polar coordinated and the electronic map and the algorithms which compute routes and methods to get back on the computed routes if that route is deviated from. A road type GPS system will rarely tell you to stop and tell you turn around because it has detected an incorrect turn off. i.e. there might be 2 right hand turns within 50m - well within GPS error within limited sky view and hence a large HDOP error. That wrong turn will eventually be detected but the GPS algorithm to get you back to the correct turn off may involve a long and tiring circular route back to the same turn off point rather than telling you to Stop and backup the same road you've just traveled down.

For example the variable nature of the speed of the vehicle may increase errors if the velocity filtering is poorly implemented. GPS systems also cannot detect direction or acceleration very well without filtering a number of position data sets so the update rate of the GPS is important. The GPS circuit might be updating every 1 sec or every 10 or 30 sec for example to save battery power.

A lot depends on the accuracy of the electronic map. The map may have been produced from a very old survey on a different map datum for example. It may have been produced from satellite or aerial imagery or ground survey. There is a lot of computation that is also required for datum conversion to cater for different map datum transformations i.e. WGS84 to OSGB36 for UK Ordnance Survey maps (which are very intuitive easy to use and accurate grid type maps). This conversions all have inherent errors transforming elliptical polar coordinates such as WGS84 to grid mapping types where they tend to loose some accuracy at the edges of the grid.

http://www.movable-type.co.uk/scripts/latlong-convert-coords.html

Solar storms may increase TEC atmospheric errors (most GPS don't have access to both L2 and L1 bands, then there is multipath errors where more costly GPS antennas are required to reduce this error. Turning on WAAS or EGNOS will also affect circular and spherical positional error probabilities.

Out of band interference from other microwave signals such as Lightsquared will most likey produce random additional errors.

Then there is deliberate Jamming and Spoofing.

All these error can sometimes conspire to send folks over a cliff.
Posted by: Am_Fear_Liath_Mor

Re: Stranded for 49 days - 05/16/11 11:35 PM

Quote:
I had a funny GPS experience about 2 years ago: I drove off the edge of the world ! Yes really !


That happened to a Squadron of F22 fighter jets as well when they first flew from the USA to Japan. Luckily they managed to follow the tanker aircraft in the right direction or they would have most likely have had to have ditched in the Pacific ocean.
Posted by: Aussie

Re: Stranded for 49 days - 05/16/11 11:45 PM

Originally Posted By: Am_Fear_Liath_Mor

That happened to a Squadron of F22 fighter jets as well when they first flew from the USA to Japan. Luckily they managed to follow the tanker aircraft in the right direction or they would have most likely have had to have ditched in the Pacific ocean.



A GPS "failure" when crawling through a sand dunes at walking speed is not really a big deal. In a jet, over the ocean would be really worrying !

And I think Australia is looking at buying a few F22s - hopefully no one will ever invade via Steep Point or we're out of luck !
Posted by: Eric

Re: Stranded for 49 days - 05/17/11 01:08 AM

I guess I'll agree that most people don't understand GPS. What most people call GPS is a GPS receiver tied to a navigation package of some sort. GPS is nothing more than a positioning system that works (very rough description) by comparing a set of timing signals against a "catalog" of satellite data. The accuracy of the timing data (and the catalog) along with the distances involved allows the position and probable error values to be calculated. Height is always less accurate than lat / lon due to the geometries involved. All a GPS can tell you is where you are or maybe some track and velocity information if you integrate position data over time. Getting access to more accurate timing data can dramatically improve the position accuracy as can some other tricks (known as WAAS and LAAS).

Every GPS I have ever used (even the horrible navigation system in my wife's car) has provided (somewhere) an indication of how accurate its positioning is. Figure out where that is on your system. As long as you know the error margins and characteristics (i.e lateral is considerably more accurate than vertical) even commercial GPS is a decent and reliable system for figuring out where you are.

Most so-called GPS errors are actually navigation system or map generation errors. I might trust the routing of a commercial avionics Flight Management System which is designed with a lot of safety checks and subject to FAA certifications and audits. I would be less trusting of a military navigation system and trusting a navigation package in an car or hand held navigator that does not require or provide documentation of similar pedigrees in development or testing processes is just not an option. Of course the car/handheld nav systems are fun to play with and can provide good situation awareness - just don't let them think for you.

-Eric
Posted by: jshannon

Re: Stranded for 49 days - 05/17/11 01:37 AM

Residents puzzle over man who died near Ore. town

MARION FORKS, Ore. – Three miles. That was all that separated Jerry William McDonald from a cold death alone in the Oregon woods and a warm meal back at the local restaurant.

http://news.yahoo.com/s/ap/20110515/ap_on_re_us/us_pickup_truck_body
Posted by: Teslinhiker

Re: Stranded for 49 days - 05/17/11 10:22 AM

The search for Albert Chretien has been called off.

Rescuers have called off the week-long search for a British Columbia man stranded in the Nevada backcountry, saying they have covered the passable areas along the route he is believed to have taken.

I once lived in the same town as the Chretien's, they are very well liked and respected people. It is unfortunate that this story has to end in this way.
Posted by: Leigh_Ratcliffe

Re: Stranded for 49 days - 05/17/11 10:48 AM

Originally Posted By: jshannon
Residents puzzle over man who died near Ore. town

MARION FORKS, Ore. – Three miles. That was all that separated Jerry William McDonald from a cold death alone in the Oregon woods and a warm meal back at the local restaurant.

http://news.yahoo.com/s/ap/20110515/ap_on_re_us/us_pickup_truck_body


Three miles. Over what sort of terrain? On a decent road, any adult in reasonable shape can walk that in an hour.
Same distance in deep snow, and I define that as being too deep to walk through comfortably without snow shoes, you might as well be on the moon.
Posted by: Teslinhiker

Re: Stranded for 49 days - 05/17/11 12:15 PM

Originally Posted By: Leigh_Ratcliffe
Originally Posted By: jshannon
Residents puzzle over man who died near Ore. town

MARION FORKS, Ore. – Three miles. That was all that separated Jerry William McDonald from a cold death alone in the Oregon woods and a warm meal back at the local restaurant.

http://news.yahoo.com/s/ap/20110515/ap_on_re_us/us_pickup_truck_body


Three miles. Over what sort of terrain? On a decent road, any adult in reasonable shape can walk that in an hour.
Same distance in deep snow, and I define that as being too deep to walk through comfortably without snow shoes, you might as well be on the moon.


Good discussion on this story here in this thread.
Posted by: jshannon

Re: Stranded for 49 days - 05/17/11 05:20 PM

My apologies for not seeing the other post about the Jerry McDonald death.
Posted by: dougwalkabout

Re: Stranded for 49 days - 10/02/12 06:26 PM

A footnote to this thread:

Albert Chretien's remains have been found.

From the news reports, he made it to within six miles of a town before the elements got the better of him. He clearly gave his all to set things right and save his wife.

A big thank-you to the many searchers, public and private, who kept looking. At least the family has some closure.

RIP

http://www.npr.org/templates/story/story.php?storyId=162122966

http://www.huffingtonpost.ca/2012/10/01/albert-chretien-found-nevada-bc_n_1929793.html

http://www.cbc.ca/news/canada/british-columbia/story/2012/10/01/albert-chretien-body-found.html
Posted by: Phaedrus

Re: Stranded for 49 days - 10/03/12 04:36 AM

RIP. It's remarkable he made it so far. My condolences to his wife. It sounds like he gave his all trying to save them both.