Cache spots on satellite photo

[+scrapes]

To all you cache owners, when you review your hide on the satellite photo, do you find the placement of the cache to be accurate from where you actually put it? thanks all

[+dfx]

many times yes, but sometimes no.

[+StarBrand]

Sometimes.

 

It really depends - some areas around here are spot on. 10 Miles west the images are a good 100 feet off. 35 miles to the East - they are a off a good 25 feet to the North. 40 miles south - spot on again. I just can't trust them.

[+Prime Suspect]

To all you cache owners, when you review your hide on the satellite photo, do you find the placement of the cache to be accurate from where you actually put it? thanks all

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap. The photos are lined up at specific registration points (known positions that can be easily pinpointed in a photo). Because the earth's surface is curved, and because of angle differentials, there's an 'adjustment" that has to be made so that everything *appears* to line up correctly. But that involves a lot of forced compromises, which sometimes can lead to items showing up hundreds of feet away from their actual locations.

[+edscott]

To all you cache owners, when you review your hide on the satellite photo, do you find the placement of the cache to be accurate from where you actually put it? thanks all

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap. The photos are lined up at specific registration points (known positions that can be easily pinpointed in a photo). Because the earth's surface is curved, and because of angle differentials, there's an 'adjustment" that has to be made so that everything *appears* to line up correctly. But that involves a lot of forced compromises, which sometimes can lead to items showing up hundreds of feet away from their actual locations.

 

I've personally never seen one that was hundreds of feet off but I've seen a couple images that were basically illegible thus useless for finding a cache. I've used about 3000 that were fine.

[+Mosaic55]

I checked some of my recent finds in google maps and the marks are from 5 to 20 feet off of where the cache really was.

[+fizzymagic]

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap.

Google Earth is satellite photos. Actually, as a result its registration is quite good.

[+edscott]

I checked some of my recent finds in google maps and the marks are from 5 to 20 feet off of where the cache really was.

 

So was this due to satellite error or GPS error when the cache was placed?

[+DeepButi]

I check all the caches I'm going to search when on an open area. Never had more than a couple of meters (let's round up to 10 feet) of diference. Usually I can identify the group of rocks or tree where it is going to be (and it is).

 

Probably on other areas it's not so good, but here is as exact as any hand held GPS.

 

(Yes, I know, not thousand of finds, just one hundred).

[+Vater_Araignee]

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap.

Google Earth is satellite photos. Actually, as a result its registration is quite good.

have a look at the area around I-96 US-23 junction at about 101 mile altitude, then explain to me how how the USDA Farm Service Agencies & US Fish and Wildlife Service aerials are sat photos when the use aircraft for their photos.

GE uses both sat and aerials because you can not always get a clear view from space and the expense and timing can be cost prohibitive for multiple attempts. Even when you use as many different sat photo companies as Google does.

Having pure satellite photos in GE is still a few years off.

 

You learn a lot when you try to do an image overlay with terrain integration but it is still flat and ya wanna know why.

[Andronicus]

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap.

Google Earth is satellite photos. Actually, as a result its registration is quite good.

 

No they are not satalite photos. All of Google's high resolution photos are aerial. Often they are super good (you can tell what side of the tree the cache is on), and sometimes it is off by 50 yards.

[+Prime Suspect]

Despite the labels on some mapping apps, they're not satellite photos. They're aerial photos. Planes fly over and take a lot of photos, with lots of overlap.

Google Earth is satellite photos. Actually, as a result its registration is quite good.

Google Earth is an amalgam of both satellite imagery and aerial photography, depending on display altitude and location. The Google Maps that have the resolution to allow people to check cache locations are pretty much always aerial photos.

Edited April 16, 2010 by Prime Suspect

[+Smokey Bear Collector]

Many times the satellite image is accurate. The last cache I found was done with this tool. It was supposed to be a difficult cache so i pulled up the map to pinpoint the location and ended up walking right to the cache, literally. It was the fastest most accurate find I've ever made.....and the cache was a nano!

 

This was luck and happenstance...but the satellite images are a good tool and are often accurate.

Edited April 16, 2010 by Smokey Bear Collector

[Storm Buster]

I've found Google maps to the the worst. Most of the others have been spot on. But that's just me.

[+edscott]

I've found Google maps to the the worst. Most of the others have been spot on. But that's just me.

 

This is about the satellite images/aerial photos not the maps, but the images in your area are missing two zoom levels and are a bit out of focus. Both your caches should still be relatively easy to find using the Google photos.

[+Crafty Turtle]

My first few caches (before I bought a GPS) I used purely the position on Google Maps / Google Earth. I found them to be reliable.

 

Now it depends - urban ones are spot on, but bush caches where there are no significant features to map, it's too hard to say if they are accurate or not.

 

I suspect for urban caches, some COs would use the photography coordinates rather than the ground coords - if they were close enough. This would mean the icon on the map is a true visual representation of the cache's location, even when you zoom in as far as you can. I like it when people do this - for new cachers with no GPS, and also for cachers who "do the research" and appreciate reliable maps/photos.

 

Again, it depends on location - if the cache is at the corner of an old railway shed, I want to see it as thus on the photo. If it is in the wilds, and I'm relying solely on my GPS blips, then I want an accurate ground coord.

Does anyone do this? Use the map coords instead of the recorded ground coords, in order to show the cache's relationship to the features.

[+edscott]

My first few caches (before I bought a GPS) I used purely the position on Google Maps / Google Earth. I found them to be reliable.

 

Now it depends - urban ones are spot on, but bush caches where there are no significant features to map, it's too hard to say if they are accurate or not.

 

I suspect for urban caches, some COs would use the photography coordinates rather than the ground coords - if they were close enough. This would mean the icon on the map is a true visual representation of the cache's location, even when you zoom in as far as you can. I like it when people do this - for new cachers with no GPS, and also for cachers who "do the research" and appreciate reliable maps/photos.

 

Again, it depends on location - if the cache is at the corner of an old railway shed, I want to see it as thus on the photo. If it is in the wilds, and I'm relying solely on my GPS blips, then I want an accurate ground coord.

Does anyone do this? Use the map coords instead of the recorded ground coords, in order to show the cache's relationship to the features.

 

I've not seen many caches that were placed too far from a decent visible attack point. I'm OK with the aerial images from my time spent field checking Orienteering maps. The aerial's coordinates and GPS recorded coordinates should be about the same. I personally trust my photo more than the COs GPS. I go to where they say it is, then look around and figure out where it really is when there's a difference.

 

Some features in the woods that can be identified that are often overlooked are fallen trees that are at an angle that is different from the shadows of the standing trees. Their length and direction make them relatively easy to spot. Water features.. even a narrow trickle, often reflect the sun and show up easily. Even when they don't, the stream side vegetation is often different from the surrounding woods. Evergreen trees in a deciduous woods, mountain laurel patches, sycamore trees, etc, are easy to ID from the air. Large rocks and cliffs can be seen or may cast a shadow that tells you where they are. Bits and pieces of trails peek through the trees.... it's all there for you to use.

 

Here's an example of the fallen tree thing. We came from the west so the grove of Hemlocks told us when to start looking for the fallen tree.

 

[Storm Buster]

I've found Google maps to the the worst. Most of the others have been spot on. But that's just me.

 

This is about the satellite images/aerial photos not the maps, but the images in your area are missing two zoom levels and are a bit out of focus. Both your caches should still be relatively easy to find using the Google photos.

I was talking about the images/aerial photos. But I figured most were smart enough to figure that out. My appologies for not specifically saying the "images/aerial photos" on Google maps.

Edited April 17, 2010 by alwarren56