caches misplaced on topo maps

[+paleolith]

The new topo map option is GREAT.

 

Only problem is ... a few caches are badly misplaced. I'm looking at some which are roughly 200m from where they show on the topos. This is too far even to be a matter of NAD27 vs WGS84.

 

G9BD7 Mugu Peak is one example. It is on top of Mugu Peak, not 250' vertical down the slope where it's marked on the topo. Nearby caches GC99D2 and GCYV89 are displaced about the same horizontal distance, roughly 200m, in the same direction (approximately south). (I have found the first two, and the locaton of the third is clear from Google Maps and Google Earth.) GCGYY9 is also badly displaced, though possibly not as much -- but it is definitely up on Mugu Rock and not on the beach as shown.

 

Perhaps 20 miles away, on a different topo quad, G2673 appears to be placed perfectly. In fact, I think the only problems I've seen are on the Point Mugu quad. GC157PB, just a few miles away, is fine -- but it's on a different quad, Triunfo Pass. So perhaps Terraserver is serving up bad location data for the Point Mugu quad? How would one track that down?

 

I'm using Opera 9.21 under WinXP, but this looks like a data problem, not a rendering problem.

 

Edward

[+paleolith]

OK, I take the lack of response to mean that this is probably a problem with a specific topo quad.

 

How do I initiate a problem report, since there's no response here? I realize that it's likely to require a secondary report to Terraserver and waiting for them to fix it.

 

Edward

[+DavidMac]

There's probably not anything Groundspeak can do about it, since it's likely an issue with the map data, not the mapping program itself. In our area, the street maps are all shifted 80 feet or so in one direction, and the satellite images are shifted 200 feet in the other direction- now THAT is frustrating. In some spots, the hybrid view is a mess when you zoom in close enough.

[+StarBrand]

Saw a facinating presentation on maps over this past weekend. Found out that many maps have an assumed accuracy of 168 feet 90% of the time but only at well defined spots. I wouldn't count on any one map as my only source for locating a cache.

 

Even newer good maps have a published accuracy of 40 feet at well defined spots - 90% of the time.

[+trainlove]

Map data is mostly horribly unreliable. But I had thought that was limited to street maps not topo ones.

 

"All data is provided for reference only. You assume full responsibility and risk when using this device." Is a disclaimer that should be thought of when using maps in addition to electronic devices.

[+klossner]

GC9BD7 Mugu Peak is one example. It is on top of Mugu Peak, not 250' vertical down the slope where it's marked on the topo.

The TopoZone map is correct, so the USGS quad was okay. Terraserver probably had a misfeed on that page. I've seen that more than once. One Terraserver quad scan for Washington State has a crumpled corner.

[edmcnierney]

I realize that it's likely to require a secondary report to Terraserver and waiting for them to fix it.

 

Don't bother wasting the electrons or your time; Godot will show up first. I am not aware of a single topo map correction or update Microsoft's made on TerraServer since the topo maps were first released there in 2000. They don't care at all about the maps; they just wanted pictures for people to look at.

 

Please excuse the horn-tooting, but if you want accurate topo maps, use TopoZone. We care about data accuracy and we have corrected literally hundreds of errors in the USGS topo map data. If someone reports a problem we investigate it and either fix it or explain why it's either not fixable or not an error.

 

As klossner pointed out (thanks), the TopoZone link for this cache is correct. There's no problem with the original map data - the problem is most likely a map metadata error Microsoft didn't find or fix, or a processing error on their end.

 

- Ed (TopoZone map guy)

[+Raine]

TopoZone should create a GMapType for me and I'll switch it to that one

 

-Raine

[+paleolith]

Hey Ed (we've talked before),

if you want accurate topo maps, use TopoZone.

I don't doubt it. If gc.com could link to topozone instead of terraserver, that would be great. Would the cost be worth the advertising to you? I have no idea.

 

Thanks to the various reponses, even though they basically all say "don't waste your time trying to fix terraserver".

 

Edward

[+paleolith]

Well, I just tried searching directly on Terraserver for the coordinates of two of the caches I mentioned. And guess what -- the results are correct. So it appears that the problem is NOT Terraserver's underlying data, but some miscommunication between Terraserver and gc.com. I wouldn't doubt that it's a Terraserver problem, but the assumption we've all made that the problem is in the underlying data appears to be incorrect.

 

Edward

[+StarBrand]

....

If gc.com could link to topozone instead of terraserver, that would be great. ...

ummmmmm - they do. On every listing page.

[+paleolith]

If gc.com could link to topozone instead of terraserver, that would be great. ...

ummmmmm - they do. On every listing page.

Not as part of a map that shows caches, or can be swapped between topo, satellite, and street.

 

Edward

[edmcnierney]

If gc.com could link to topozone instead of terraserver, that would be great. ...

ummmmmm - they do. On every listing page.

Not as part of a map that shows caches, or can be swapped between topo, satellite, and street.

 

Edward

 

Take your pick - do you want a map service that's free, or one that's accurate? We've got aerial (not satellite) photos and street maps that are better than Google's (in the US) and topo maps that Google doesn't have at all. We can overlay street maps on topos and aerial photos, and provide information like exact elevation data you don't get elsewhere. But we don't get things for free and need subscribers who think those services are worthwhile to pay for them.

 

It's perfectly OK to decide that you're not willing to pay for the data you use - if it's not worth anything to you, you shouldn't pay for it. But you don't have much grounds for complaint if what someone gives you for free isn't good enough for your needs. Not everyone buys a GC.com premium membership, either, but if you want those premium features it's perfectly reasonable to pay for them.

 

We don't provide GMapTypes - we provide map data to many other sites using open, industry-standard protocols, not single-vendor proprietary ones.

 

We'd be very happy to provide custom GC.com features for TopoZone Pro subscribers. No one's ever asked us to do that, and it's possible that there aren't enough GC.com users who would be interested to actually make it worthwhile.

[+klossner]

Well, I just tried searching directly on Terraserver for the coordinates of two of the caches I mentioned. And guess what -- the results are correct. So it appears that the problem is NOT Terraserver's underlying data, but some miscommunication between Terraserver and gc.com. I wouldn't doubt that it's a Terraserver problem, but the assumption we've all made that the problem is in the underlying data appears to be incorrect.

It looks like it's terraserver's problem. They don't properly handle their own URL:

terraserver-usa.com/GetImageArea.ashx?t=2&s=12&lon=-119.055116667&lat=34.0925666667&w=500&h=500&p=26:-119.0551167:34.0925667

[+paleolith]

It looks like it's terraserver's problem. They don't properly handle their own URL:

terraserver-usa.com/GetImageArea.ashx?t=2&s=12&lon=-119.055116667&lat=34.0925666667&w=500&h=500&p=26:-119.0551167:34.0925667

So it seems. Lovely. FWIW I submitted a support request on terraserver.com. I'm not holding my breath.

 

Ed, yes, I prefer to pay for services I receive on the web. Unlike most people, I'd prefer that those providing the services be beholden to me rather than to the advertisers. That said, I can't quite reconcile the added value of topozone with the $50/year cost of Pro -- not for geocaching maps alone. Mind you, I'm not arguing that you could do it for less -- my image of you does not have you driving a BMW. But if topozone and gc.com had an arrangement by which I could pay $15 extra with my gc membership to be passed on to tz and which allowed me access to tz maps in the regular gc map window, and only there, I'd pay it. It would be worth $15/year just to be able to get this kind of problem reported and fixed. To how many is it worth this ... I don't know. For the kind of caching I do, topo maps are as important as street maps and somewhat more important than satellite photos. Those who do park and grabs aren't likely to go for it.

 

And if there were no topo maps at all on gc.com, and $50/year would get them integrated with the gc.com maps, then I'd pay it. Just linking me to a topo of the area isn't much help; I want the map overlayed with the caches. However, you (like a lot of providers) are in the unenviable position of not only trying to provide value for payment, but of trying to provide added value beyond advertising-supported services and free services for payment. (As far as I can tell, Terraserver is still in the category of free rather than ad-supported services, though I may have missed something.) And of course you are also competing with libremap.org on a slightly different front. I have no good advice. Even I, despite my preference for paying for services, still evaluate the difference at least as much as the absolute.

 

Edward

[edmcnierney]

Thanks for the notes (sorry for the slow reply - I've been out of town).

 

I think that all makes a lot of sense. I just wanted to add two clarifications:

 

1. Terraserver.com is not at all the same as Microsoft TerraServer at terraserver-usa.com. Terraserver.com is a completely separate business (somewhat more like ours at TopoZone) created from the initial joint Microsoft TerraServer business. They parted company several years ago, but Terraserver.com was allowed to keep that incredibly valuable (due to user confusion) domain name. The "TerraServer" maps on GC are from Microsoft TerraServer and not from TerraServer.com

 

2. The libremap.org project is a bizarre non-solution to a non-problem. I don't pay much attention to it, but it's kinda weird and mostly seems like a Jared Benedict self-promotion project. Before it came along the USDA already provided a complete set of USGS topographic maps for free download, so the alleged complaint that "the Federal government doesn't make these available for free" just wasn't even true. And the belief that archive.org, an effort primarily funded through the philanthropy of one guy, is somehow a "permanent" solution is unreasonably optimistic. And the "complete" set of USGS DRGs made available is neither current nor complete (e.g. see any Puerto Rico maps there?). There are many state governments who provide free DRG downloads, often in enhanced formats, and we often refer users to those sources. The libremap.org library is just another one of a long list of online sources.

 

Our TopoZone Pro subscription is primarily designed to provide a service that makes it easier to find and download maps. We're not trying to "sell" you the maps rather than selling the convenience of an integrated set of data that's easy to use - type in a street address, click three times, and you've downloaded the DRG at that location. That's what we want our subscribers to value. If that's not important to you (and there are LOTS of people for whom it's not important) then that's not something that you should buy. If you need to do that several times a day, every work day, then we think $50 is a really good deal.

 

Ed

 

P. S. Full disclosure #1 - I had a long email conversation with Jared Benedict a few years ago as I explained to him that after he purchased a $50 TopoZone Pro subscription he was not entitled to download 59,026 topos from us and distributed them on his own Web site. Just because it's public domain data doesn't mean (a) I have to give you my copy for free or ( I can't impose contractual restrictions on what you do with a copy if you get it from me. Anyone could have obtained the DRGs from the USGS, TVA, and State of California and done whatever they wanted with them, just like I did.

 

P. P. S. Full disclosure #2 - No BMW - a 2004 Prius, with GPS, of course....