#266140 - 12/28/13 03:18 PM
Re: CrowdSourcing SAR Searches
[Re: UTAlumnus]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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Google Earth resolution depends on the source. If the light is hitting it right, you can even see some of the power lines in the current image they use of my house. Older images range from off color & slightly fuzzy to very fuzzy. GE uses a wide variety of imagery from many sources. The higher resolution stuff is mostly conventional air photography from a wide variety of public domain sources (USGS, states, municipalities, etc). The satellite imagery is mostly SPOT, with about 2.5 meter resolution. The Wikipedia article on Google Earth has good info. Since GE images will generally date from before a person became lost, they will be useless for spotting a lost person directly. However GE images can be very useful as a look at terrain and man made features for search planning. It is often used for that purpose. To try to use imagery for spotting a lost person by "crowd sourcing" one would need high resolution images acquired after the person became lost. Apparently this was what was tried in the search mentioned in the OP.
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"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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#266141 - 12/28/13 03:30 PM
Re: CrowdSourcing SAR Searches
[Re: hikermor]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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Even then they would need a valid start point. They are essentially trying to track this person via satellite imagery without a ground truth. What did the terrain features look like just before he passed by and what changed? What would a tracker on the ground expect to see while following someone not trying to hide? A person is not going to change terrain features enough to be detected by mediocre resolution imagery without doing something big and deliberate. It won't see footprints and certainly can't determine boot-size or whether that's the right pair of Danners.
This is how desperation manifests and is another reason to stop, set up camp and get a good smokey fire going. Or carry a PLB and a signal mirror. All of the above?
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#266142 - 12/28/13 05:11 PM
Re: CrowdSourcing SAR Searches
[Re: AKSAR]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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Coincidentally, while enjoying some post Xmas relaxation and web surfing at my in-laws, I just ran across this: Two Views to Earth . Apparently, near realtime 1 meter resolution satellite imagery will soon be available. Skybox has meter-scale resolution on the ground as well. The planned constellation of satellites will eventually total 24, and they sell the data to users much like Urthecast. .............these data could also provide rapid nearly real-time data in emergencies, long time baseline observations of various activities on Earth (sure, for intelligence purpose, but also to see how, for example, farmland and forests have changed as our climate changes, and so on), and many things we may not have even thought of yet.
_________________________
"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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#266143 - 12/28/13 05:48 PM
Re: CrowdSourcing SAR Searches
[Re: Russ]
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Veteran
Registered: 12/14/09
Posts: 1419
Loc: Nothern Ontario
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Even then they would need a valid start point. They are essentially trying to track this person via satellite imagery without a ground truth. What did the terrain features look like just before he passed by and what changed? What would a tracker on the ground expect to see while following someone not trying to hide? The missing hiker is thought to started in the Lynn Headwaters Park area. I know that area quite well and in the lower elevation areas, it is a very popular hiking area and has well marked trails. However once you get into the back country past Norvan Falls, the terrain can be quite challenging and you need to be well equipped to attempt to hike up in there. I don't think this person would of hiked that high up into the back country, but you never know. One of the good/bad problems this year is the low snowfall but along with the rain, cooler temperatures and short daylight hours (it gets dark up there early) means that ill prepared people will push themselves past their normal limits and find themselves in trouble before they know it. Today, it is foggy here and I would suspect that same area is also socked in with fog and clouds.
_________________________
Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.
John Lubbock
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#266145 - 12/28/13 05:51 PM
Re: CrowdSourcing SAR Searches
[Re: AKSAR]
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Sheriff
Carpal Tunnel
Registered: 12/03/09
Posts: 3842
Loc: USA
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Apparently, near realtime 1 meter resolution satellite imagery will soon be available. This could drastically reduce the time required for some searches, especially if the weather is good and the person who needs rescue is able to make a large, high-contrast signal, such as a big "X".
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#266188 - 12/30/13 08:17 PM
Re: CrowdSourcing SAR Searches
[Re: Teslinhiker]
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Old Hand
Registered: 08/10/06
Posts: 882
Loc: Colorado
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During the Fossett search there were frequent efforts to offer updated imagery because of the obvious condition that your pictures have to be taken AFTER the object has been lost.
In the case of resolution- areas I occasionally look at for hiking have some newer, much higher resolution, imagery on GE right next to areas with older, lower resolution imagery. So GE results can vary.
Near realtime imagery is expensive.
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#266190 - 12/30/13 08:47 PM
Re: CrowdSourcing SAR Searches
[Re: unimogbert]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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Unless you're looking at some of the street view imagery, about the best resolution I've seen on GE is 1 meter. 1 m resolution is fine for some applications, but I have my doubts that this is one of them.
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#266192 - 12/30/13 10:13 PM
Re: CrowdSourcing SAR Searches
[Re: chaosmagnet]
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Veteran
Registered: 08/31/11
Posts: 1233
Loc: Alaska
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Apparently, near realtime 1 meter resolution satellite imagery will soon be available. This could drastically reduce the time required for some searches, especially if the weather is good and the person who needs rescue is able to make a large, high-contrast signal, such as a big "X". Unless you're looking at some of the street view imagery, about the best resolution I've seen on GE is 1 meter. 1 m resolution is fine for some applications, but I have my doubts that this is one of them. One meter resoulution might help in a few SAR cases, such as when looking for a lost vehicle or downed aircraft. Looking for lost hikers, not so much. (Unless, as chaosmagnet says, they make a really big symbol.) Note that any quoted figure on "resolution" (such as 'one meter') probably refers to optimal conditions. As chaosmagnet also implies, weather is always the bane of satellite visual imagery. Any image taken from space will always have to penetrate the entire thickness of atmosphere. Any clouds, smoke, haze, etc will degrade the quality of the image. Aircraft imagery will always have an advantage in this regard. Besides being much closer to the target (hence not requireing nearly as much optical magnification), an aircraft will be below at least part of the atmosphere. I was reminded of this while landing in Anchorage yesterday, after our Christmas visit down south. As we approached Anchorage at altitude, all one could see was the tops of a few mountains poking up through the clouds. Once we descended below the clouds on our approach, it was quite clear. The great advantage of satellite imagery (for civilian use) is being able to see large areas at one time. Near realtime satellite views with 1 m resolution could be extremely valuable for disaster management. Think of something like a flood, hurricane, tsunami, or earthquake. An emergency response planner could immediately see which areas were hardest hit, to help decide where to deploy assets. He/she could see which bridges were still standing, and which roads were blocked. This would be very useful for routing convoys of relief supplies. Air photo missions have been launched especially for SAR. I don't have a link handy, but I recall hearing of one a few years ago looking for missing climbers in the Alaska Range. My recollection is that they never found the missing party they were looking for, but did spot the body of a Japanese climber who had gone missing some years before. Just a bit of red parka was visible in the ice on a wall.
Edited by AKSAR (12/30/13 11:09 PM) Edit Reason: Add note on resolution
_________________________
"Toto, I've a feeling we're not in Kansas any more." -Dorothy, in The Wizard of Oz
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#266194 - 12/30/13 10:30 PM
Re: CrowdSourcing SAR Searches
[Re: AKSAR]
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Rapscallion
Carpal Tunnel
Registered: 02/06/04
Posts: 4020
Loc: Anchorage AK
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Now there is a great application for drones. The wonder of it is, you could unleash literally hundreds of drones to search an area. The tech we have access to nowadays will find people who are well hidden in desolate areas under adverse conditions.
I can't think of a better use for these things than SAR. Risk mitigation with drones is also a major factor. In fact, I could see where a drone could be used to locate a victim, provide valuable resources, communications etc, and give SAR teams a hard target to home in on and effect rescue.
As a public investment, especially up here in AK, I would think Drones would the real deal. Imagine what just 50 drones equipped with good AI and a full sensor array (flir, night vision, high res, sound sensing, chem trail tracking,seismic, etc) with a 1,500 mile range and a cruising speed of 250 knots could accomplish.
We had robotic ground rovers years ago that could track rabbits out in the desert. Every once in a while one would traipse through a contaminated area, then spread radioactive material into a sensitive area. They tracked the animals the same way a hound does. Pretty darned effective.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer, English Philosopher (1820-1903)
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#266196 - 12/30/13 10:56 PM
Re: CrowdSourcing SAR Searches
[Re: benjammin]
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Veteran
Registered: 12/14/09
Posts: 1419
Loc: Nothern Ontario
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Now there is a great application for drones. The wonder of it is, you could unleash literally hundreds of drones to search an area. The tech we have access to nowadays will find people who are well hidden in desolate areas under adverse conditions.
I can't think of a better use for these things than SAR. Risk mitigation with drones is also a major factor. In fact, I could see where a drone could be used to locate a victim, provide valuable resources, communications etc, and give SAR teams a hard target to home in on and effect rescue. Another one of our local SAR teams did some testing with small drones earlier this fall. One advantage I see with these sized drones in our mountainous terrain which is punctuated with deep narrow ravines and gullies along with dense tree cover, is the ability to maneuver into these type of areas much easier then larger drones.
_________________________
Earth and sky, woods and fields, lakes and rivers, the mountain and the sea, are excellent schoolmasters, and teach some of us more than we can ever learn from books.
John Lubbock
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