Google Earth

Posted by: Xelif

Google Earth - 10/24/07 08:42 PM

Hey everyone,

I've been using Google Earth a lot recently for hiking related pursuits. If you aren't familiar with it, it's a mapping program that generates a 3D relief view you can move around in and pan, swivel, zoom, etc. Google Earth Download (Free)

I've been using it to first spot trails through the trees, then to identify distant ridges, parks, and mountains. This is one of the most useful features for me. I can stand at a vista point in reality and memorize the terrain layout (or take some pictures), noting especially distinctive ridges, hilltops, mountains, etc. Later at home I will load up Google Earth, find the vista point I was standing at earlier, tilt the view to 'look' where I was seeing in reality, and then move to a distinct ridge in the distance. It let me find out what's around the ridge or peak, the name of it, potential trails or parks, and distance measurements. Sometimes there are pictures from public photo collections and Wikipedia articles.

I've found a lot of fascinating things like reservoirs, trails to hills a few miles distant, creeks, and even a potential very long route to Mt. Diablo, a local landmark. I've hiked to several of these features, it's a great thing to get a glimmering of something in Google Earth and then walk to see the reality of it! You can also use the ruler to measure distances; I could see about 40 miles two days ago, to a short mountain in the north. You also can measure altitude and position exactly, under the mouse cursor.

Finally, I just started overlaying hiking maps from my local parks onto the terrain provided in Google Earth. It's a pain to get right, but lets you see the trails otherwise hidden or not shown.

Anyone else use GE (Google Earth)?
Posted by: Earthling

Re: Google Earth - 10/25/07 12:37 PM

<img src="/forums/images/graemlins/ooo.gif" alt="" /> Sounds exciting, I'll have to pencil in some time for that now <img src="/forums/images/graemlins/smirk.gif" alt="" /> Honestly, i can barely keep up with this single forum, let alone explore the Earth on the computer <img src="/forums/images/graemlins/blush.gif" alt="" /> But, it sounds promising to folks who want to poke around before they go on a trip. thanks for the tip <img src="/forums/images/graemlins/grin.gif" alt="" />
Posted by: Trailrunner

Re: Google Earth - 10/27/07 01:12 PM

Yep. Last month I did a 54 mile, 6 day trip through the Mineral King area with some work buddies. We sat down and "hiked" the trip on Google Earth first.
Posted by: Jimshaw

Re: Google Earth - 10/27/07 03:44 PM

Trailrunner
There doesn't seem to be enough resolution. Did you learn much from the virtual tour?
Jim
Posted by: Xelif

Re: Google Earth - 10/27/07 07:42 PM

Did you wait for detailed imagery to load while zoomed? The longer and more closely you view an area, the more detailed the view gets. It shows a status bar at bottom center area.

(edit) Also there's the chance you inspected an area that is only covered by satellite imagery, in which case it'll look horrible close up. To see the 'best' resolution, zoom in on a house in or near a city, and you'll get an idea of how it looks at the finest level.
Posted by: Trailrunner

Re: Google Earth - 10/28/07 01:41 PM

Jim, it depends on how you define "much". It certainly gave us a "feel" for what we would encounter, more so than any topo map could. It definitely didn't show us every bump in the trail but it did give us a good idea of the general vegetation or lack thereof. And we were fully aware that we were not looking at a real time image. But it is much more real time than many U.S.G.S. topo maps which have not been revised for many years.

Considering the cost ($00.00) and the fun factor I would recommend GE to anyone.

As a side note, one of my other hobbies is locating old military plane wrecks/crash sites. I have learned lots of ways to locates these sites using images from GE.
Posted by: Paul

Re: Google Earth - 10/28/07 02:23 PM

I use it all the time. Besides being very useful to get the lay of the land before you go, it's way fun. I find the resolution varies considerably from one area to the next, and it's [Edited for inappropriate languge, please review forum policies for more information] wierd to be looking at summery conditions on one spot with a sharp line dividing that from a snowy section because the two photos were taken at different times of the year. It helps to have a fast computer and a fast internet connection - with a slow setup it would mostly be a waiting game.
One thing I have been able to do is to confirm the spots where people took photos from. By adjusting the viewing angles and comparing the spot I think the photo was taken from, I can sometimes get a real close match and confirm the spot. This only works with photos taken from high points - peaks, passes, ridges - beacuse you can't get the right angle otherwise.
Now if only we could get real-time images like these!
Posted by: Jimshaw

Re: Google Earth - 10/29/07 04:04 PM

oh WOW <img src="/forums/images/graemlins/laugh.gif" alt="" />
I found the tilt function - whoah this was secrrett technology 25 years ago... <img src="/forums/images/graemlins/crazy.gif" alt="" />
I can see now how a virtual hike would be meaningful.
check out the three sisters and mt bachelor, they're 20 miles west of my house.
44,05, 03.91N
121,43,40.43W and tilt and zoom.
Jim
Posted by: ChrisN

Re: Google Earth - 12/06/07 04:18 PM

I use it all the time now. It's a great way to find huge alpine meadows (my favourite haunt) and figuring out ways to get to them. I've discovered a number of really interesting places that way. I usually start with Google Earth to figure out a destination and then get topo maps to work out specific routes. I've noticed that the resolution varies quite a bit. Around Whistler (north of Vancouver), the resolution is almost down to individual trees (probably the ski hills paid for the better resolution).
Posted by: chaz

Re: Google Earth - 01/05/08 05:09 PM

I've been using GE for some time and have used to map a trip. I'm interested in the plane wreck sights you found. What area of the country are they? Do you have coordinates so I could view them on GE. Cool Thanks <img src="/forums/images/graemlins/cool.gif" alt="" />
Posted by: MattnID

Re: Google Earth - 01/05/08 05:34 PM

I use GE religiously before and after trips. It just gives me a better idea of what to expect and what I'm probably going to be seeing on the ground. By the time I finally go out, I've got it all down in my head. A nice little research tool.
Posted by: CAMOEDTJ

Re: Google Earth - 02/06/08 07:15 PM

just wondering if any body has actually looked at their gps utm locations and compared them with ge. i was looking at my gps and comparing ge utm cords and they werent even close to the same location.my gps is waas capable and the spots marked on the gps were in a clear area with gps reading accuracey to 1meter. hmmmmmmmm mabe im missing something here..
Posted by: NiytOwl

Re: Google Earth - 02/07/08 01:16 AM

I routinely take the breadcrumb data from the GPS application on my Pocket PC and import it into GE as a kml file. For 98% of the time it's dead on - within 10 feet - of what GE shows. The remaining 2% - well, it's usually when I'm in a ravine, under a bridge, or under very heavy tree cover. FWIW, my GPS module uses the Sirf III chipset, so my best accuracy is within 10 feet.

Keep in mind that just because your unit has WAAS capability, it doesn't mean that it's actually being used. Also, the number of satellites being received and their location has a lot to do with how accurate the GPS is. If your GPS has a stat called "DOP" you can get an idea of how accurate the position is. DOP is Dilution Of Precision. Ideally you want DOP to be under 2. That's within about 10 feet. DOPs higher than 5 are getting into the 30-foot plus errors. I owned a WAAS GPS that would experience DOPs of 10 or more under tree cover. That's near 100-feet of potential error. Its accuracy was dramatically improved by the addition of an amplified external antenna. This did result in shorter battery life, but it was worth the improvement in accuracy.

DOP gets high when the satellites "seen" by the GPS are close together. That's why accuracy is bad in narrow canyons. In fact, canyons can make things even worse if they introduce multipath reflections. This can make a GPS think you are hundreds of feet away from where you really are. I've had this happen when hiking between peaks - the GPS suddenly indicated that I was rapidly moving in large circles.

It is also possible that the satellite maps in GE are wrong for the area in question. If you really want to be certain if the problem is GE or your GPS, you can use a site like Groundspeak to find a benchmark in your area. You want a benchmark with adjusted coordinates, not scaled. Compare the coordinates of the benchmark to what your GPS reads and what GE indicates.
Posted by: CAMOEDTJ

Re: Google Earth - 02/07/08 07:18 PM

thanks niytowl those are some great links, ive dot some reading to do now.
Posted by: BrianLe

Re: Google Earth - 02/08/08 04:45 AM

NiytOwl said:
"I routinely take the breadcrumb data from the GPS application on my Pocket PC ..."


My GPS is a sirfstar III on a pocket pc too. What GPS app do you use? Does it give UTM coordinates, and are there things you particularly like or dislike about it?

Thanks!
Posted by: Brumfield

Re: Google Earth and Mexican cops - 02/17/08 01:38 PM

Been using Google Earth Plus to grid search for small villages along the Pacific coast between Michoacan and Chiapas that are not on any maps. With it I can see the villagers' foot trails through the jungles and mountains, especially if any of the images were made during the dry season.

Using GE, I once was able to avoid going near an interesting "farm" east of Zitacuaro, where I'm sure I would not have been welcome. I stayed far away from there and later saw police reports coming out of Morelia stating that The Michoacan Family were located in that same area. There's not so much a problem with The Family, it's the local cops, who've had friends beheaded, that will think you're supporting The Family and take you for a one way hike in the jungle.

Yep, GE has many uses, but getting caught with a satellite view of some areas down here has caused me some very tedious discussions while being searched, which is happening more often than usual. I now Google birds native to the areas I'll be traveling in, and print and carry two or three color pics of the local birds among the relative GE images. I always carry small binoculars on my pack strap for scouting a trail, and I make a point of letting them be seen during a search. It's worked so far, and the macho cops all get a good laugh from my bird pictures... sometimes they get in an argument over the birds' names. I guess the police don't feel threatened by a birdwatching gringo, they (mistakenly) think gringos are all wimps anyway, especially birdwatchers.. I also now know the names of some of the birds I see.

The 40 pounds of Spanish Bibles in my pack help to disarm the police here too. I offer a Bible to every cop that stops me, most ask for more copies, so... I've added a nylon hand-carried duffel full just for the searches, in order to have some Bibles left when I get through the check points and off the roads.

But, as things would be down here, the cops don't have any problem with me carrying a 20 inch machete in full view. <img src="/forums/images/graemlins/smile.gif" alt="" /> Brum

Posted by: oldranger

Re: Google Earth and Mexican cops - 02/17/08 07:36 PM

But a machete is just normal male attire there right? I hadn't been in Oaxaca for two days before I picked up one for myself. Just seemed the right thing to do.

That was years ago, and Mexico seems like a much tougher nut these days. Keep safe and avoid those "farms."
Posted by: Brumfield

Re: Google Earth and Mexican cops - 02/18/08 03:17 PM

Quote:
But a machete is just normal male attire there right? I hadn't been in Oaxaca for two days before I picked up one for myself. Just seemed the right thing to do.

That was years ago, and Mexico seems like a much tougher nut these days. Keep safe and avoid those "farms."


Normal male attire, yes, and I sure agree that it just seems the right thing to do. But it still kinda throws me for a few seconds when I see someone kneeling in church with a machete hanging from their belt or slid under the kneeler in front of them. It's a bit crazy in some areas here, but I think it's the times and not so much the location. Brum