Hiding Caches with a Smartphone..

[rinsemesocks]

I can't understand why Sat Maps aren't acceptable to do co-ords for urban hides. It is a lot easier to find caches particularly as using a sat nav is usually iffy to find them. Would it be rude to say that averaging co-ords is so last century.

[ikkibrady]

I've hidden a coue with just a smart phone and took general coords and used google maps to make it accurate

[CraigRat]

I've hidden a coue with just a smart phone and took general coords and used google maps to make it accurate

Ugh, be careful with that, google maps (especially satellite view) are not as accurate as one might think.

The sat maps can easily be out 10-20m and in some areas nearly 50!

I can't understand why Sat Maps aren't acceptable to do co-ords for urban hides.

Because the images are not correctly aligned in most cases, that's why.

[Papa Bear_Left]

and Google Maps, for one, varies a lot from place to place.

There are places in SA where it seems to be dozens of metres off! And other places where it seems spot-on.

[Yurt]

Of course you could get GPSr-free caching going (well it's been going for a while) by only using Google Earth imagery and telling people to ignore the coords and just use the satellite view. All well and good if the resolution of the image is pretty high and it's not under trees and the area isn't a new development etc - some of the Google Earth imagery is from 2007 or so meaning suburbs like The Ponds in NW Sydney aren't all on there.

[Laighside Legends]

I find that google maps is nearly spot on in and near the CBD but in country areas it can be 10-20m out.
That said, Bob from elsewhere has somehow managed to find 1000 and something caches using nothing but google maps...

[LouiseAnn]

That said, Bob from elsewhere has somehow managed to find 1000 and something caches using nothing but google maps...

Wow, impressive! Rather him than me.

[Zalgariath]

Also depends on the phone and the hider. You can average co-ods on both iPhone and Androids and each model has a varying quality of GPS chip. If the person knows what they are doing, there should be no problem with a modern phone assisted in the city where a real GPS would struggle anyway. Outside of urban canyons and especially phone range, most still wont compare to a dedicated, but with care and averaging you would be within acceptable variation.

[Bunya]

This must have been raised as an issue in the US too.
In the latest Groundspeak Weekly Newsletter under "Be a Better Hider" they say:

2 - Location
Geocaching guides treasure-seekers to a precise set of coordinates. The adventure begins there. Make sure that "there" is the right "there." You should double (even triple) check your coordinates using a dedicated GPS receiver. Avoid using smartphones to establish coordinates for new geocaches.

[Yurt]

I noticed that too. Was about to post that but you beat me to it.

Then there's this:

1 — Land Owner or Manager Permission
Make sure to get permission from the land owner or manager before placing a geocache - even many public locations require permission. This step will help to offer a great experience to geocachers without them being concerned about seeking the cache at that location, and means you won't need to worry about cache removal.

Er... yes... okay...

[Papa Bear_Left]

Oh, the horror stories I've heard from US reviewers... Mostly from cache-placers using older iPhones (the ones that didn't have a GPS receiver, just a guess based on nearby cellphone towers and wi-fi hotspots), who then followed up the inevitable DNFs from the poor inadvertant beta testers with requests for coord updates, often hundreds of feet away.

[2max]

Thank you very much to absolutely everyone who has taken the time to comment and give their thoughts, I really, really appreciate it and have taken it all on board. I did my three checks on the first place I had earmarked to put a cache, and then returned again today to do another check and actually put the cache in place - hopefully all going well it will pass the reviewers test. I made sure that the hint was clear on exactly where to look to find the cache. I'm pretty excited about this spot and hope others may also find it interesting.

I still absolutely most definitely want to buy a GPSr, though as I mentioned in my opening post money is a little tight right now - but in a strange twist of fate whilst I was out placing the cache my name was being drawn out of a raffle I had entered earlier this morning. Received a phonecall this evening about it, seems they were going to see if they could send me out my prize as part voucher/part cheque. IF it comes as part cheque, I'll take it as a big fat omen and use it to go buy myself a GPSr. So I now have my fingers crossed.

[2max]

If you hide it with an iphone on the groundspeak site, and it is an iphone with a real gps like an iphone4, make sure you say that. If you hide one with a iphone3, the reviewer will knock it back as it wasn't hidden with a phone that has a real gps. I know this from early experience in hiding and I had to switch to an android phone [from which I have never looked back from].

Thanks for that great piece of advice rinsemesocks, yep I have an iphone4 so have included a note to the reviewer to tell them this, and let them know that I also did multiple coordinate checks. Hope that it will all pass.

[2max]

A simple check on your coords is to just stick them in Google Maps, switch to satellite view and zoom right in to see where it's showing. I don't know how accurate the maps are but they seem pretty good - and its a good way to catch typos too. The cache reviewers seem to use this (I had a comment about one of my hides), and I often use it for making tricky cache finds easier/quicker, and finding the best approach routes.

Thanks quiet1, I tried this out and although the satellite image appears to be outdated by at least 5 years, from what scant bearings I can make out, the coordinates do look pretty accurate. Ta

[Rabbitto]

I'm thinking along the lines of that if I go with the 3 visits and check the coordinates for averaging, that I will make sure that I do it in good weather just to be on the safe side.

Another interesting thing to do is to take the coordinates, walk 100m away and come back and look at where you are standing at 0m. Then walk off in a few different directions and return and look where you end up each time. If you keep ending up more often than not on one particular side of the cache, manually move the co-ords in that direction a little by one or two .001's of a minute. Repeat the process until you are ending up roughly equally on all directions of the cache ie, sometimes you come in a couple of metres to the north, but equally, you will end up the same number of times to the east, south or west. Once this happens, you are probably getting close. Then use those co-ords on the other days to check.

Don't forget too that if your co-ords end up being out by even, say 10m, stand at your cache and look at 10m in every direction. What types of things are located within that search area. Look for things that you don't want cachers destroying like garden beds, private property, or dangerous spots and the like. Remember that people will be not only searching at your GZ but also in that vicinity. What sorts of instructions do you need to include that will stop that from happening? Then there is the multiplier. if you are 10m out and someone else is using a fairly inaccurate GPSr that is also 10m out at the time of searching, that circle could potentially have a 20m radius. What is in 'that' circle?

Another thing to remember is that GPSr signals can be easily blocked, especially on those weaker types of GPSr. If your cache is close to buildings, hillsides, large trees and other obstacles, some of these types of GPSrs may never give a good reading. A cache that we recently completed on a steep hill was over 35m out. (The damage to the surrounding area was substantial)

Yet another tip is to use a friend or a family member (who has no idea as to where the cache is) to beta test the cache. Watch what they do (and don't say warmer colder as that defeats the purpose). If they end up getting cross or frustrated and asking for more information, it's a fair bet that another geocacher will have the same sort of reaction. Guaranteed that the longer that they have to spend, the less fun that it will be. (Bring someone who has little kids with them and watch what happens if it takes over a few minutes)

The use of smartphones to hide caches does not nessarily mean bad co-ords. However, it will certainly take a lot more care and preparation to ensure that they are correct.