Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Sat, Apr 05, 2014 at 03:52:42PM -0500, John F. Eldredge wrote: You are being asked, is the word brunnel one you coined, or is it in use already by other people? Pointing to a page you wrote is not an answer to the question. I have used a word I found in the wiki. I did not investigate who invented it or if it was widespread but it was certainly not my invetnion. Perhaps wikiblame works for our wikipages as well? The word happened to be a good match for what I wanted so I took it. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
You are being asked, is the word brunnel one you coined, or is it in use already by other people? Pointing to a page you wrote is not an answer to the question. On April 3, 2014 5:06:54 PM CDT, Richard Z. ricoz@gmail.com wrote: On Thu, Apr 03, 2014 at 10:49:56PM +0100, Dave F. wrote: On 03/04/2014 22:04, Richard Z. wrote: A brunnel is a crossbreed of a bridge with a tunnel. It has been used somewhere to describe constructions where it is not easy to decide whether a grade separated crossing is better described as a tunnel under a road or bridge above something. Really? Are you sure you're not just making this up? Show us where or I'm calling you a fibber. How much more stupid do you want to get if you don't use the basic search function. http://wiki.openstreetmap.org/wiki/Advanced_relationships http://wiki.openstreetmap.org/wiki/Key:layer Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Dr. Martin Luther King, Jr. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 4/5/14 4:52 PM, John F. Eldredge wrote: You are being asked, is the word brunnel one you coined, or is it in use already by other people? Pointing to a page you wrote is not an answer to the question. it appears to me that brunnel is defined in the GDF (Geographic Data File) format. but the term seems to have no real world traction. Suggesting Richard Z made it up is inappropriate, but suggesting the term is in widespread use would be wrong as well. richard -- rwe...@averillpark.net Averill Park Networking - GIS IT Consulting OpenStreetMap - PostgreSQL - Linux Java - Web Applications - Search signature.asc Description: OpenPGP digital signature ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Am 03.04.2014 21:43, schrieb Richard Z: On Thu, Apr 03, 2014 at 06:08:46PM +0100, Dave F. wrote: On 02/04/2014 17:14, Richard Z. wrote: as explained in the rationale the dimensions of the bridge/culvert are frequently only a fraction of the achievable precision. Think of a track crossing a small creek in a forest valley int the mountains. The GPS precision will be 10 meters if you are lucky, the brunnel 2-3m. Mapping this the old fashioned way will produce junk data, not precision. Rubbish. Please don't rely on a GPSr. It is only one, of many, ways to survey. If I see a small bridge over a stream, say 3m I'll map is as that, because that's how it accurately is in the real world. Some users have access to detailed aerial imagery to help map accurately. so again: *** a small creek in a forest valley int the mountains *** Where is your aerial imagery? I want that!! In the mountains you are very lucky if your imagery has less than 10 meter offset and forests render most aerial imagery useless. The offset (either GPS or imagery) has influence on _where_ you can map the bridge - but not much on _how_ you are able to map it. I'm neither a friend of a crossing node when there is no connection in reality. Missing or loosing the bridge tag I would always assume a ford there ... Georg ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-03 22:42 GMT+02:00 Richard Z. ricoz@gmail.com: Don't dismiss that argument so casually. The current rule is that the way below the bridge should not share a node with the bridge itself. the current idea that culverts float bellow roads without having anything common with them is not correct in most cases. These culverts are part of an integral highway-culvert-waterway construction. The same is true for most bridges, only a small fraction does float independently above valeys but most are connected with the lower way by the actual bridge construction. The bridge structure may also be related to the riverbed structure, but ways are not. As you drive on the road on the bridge you have no idea whether down below there's a river or a stream or a valley. I could imagine adding an exception to that rule if it were hard to avoid a shared node. But in this case, it can very easily be avoided by mapping the bridge in the same manner two million other bridges have already been added: as a way. easily? So you have biked 60 miles along a forest track and know reliably that there was not a single ford on your route today. You look at OSM data in the evening and see there are 120 streams which you crossed with missing bridges/culverts. What do you do? Leave those 120 crossings in incomplete state even though someone might be really interested to know whether there are some fords on the way? Add fictional bridges or culverts? Say ford=no? This is nonsense. If two ways don't cross, they don't cross. Missing the bridge/culvert tag is a minor error: it just leaves you without information as to how that road and that waterway intersect their paths. However, if they share no common node at the intersection, you can assume that there's no way you could stop driving and dive into the water. In case there's a ford instead, map it: put a node on the intersection and use ford=yes, so people will know that *those* two ways cross with a ford. Missing the tag is missing information with a fallback that makes sense (you'd notice an unmapped ford with your eyes and go fill it in). Putting in a node is *wrong* information, and consumers would assume that the ways cross, thus ending up with a wrong routing graph (maybe they'll penalize the route thinking there's a ford). The other point - even if you know it is a bridge or culvert - is it worth painting an insignificant structure which is perhaps 3m in size when the GPS error is more likely 10 meters? In a deep valley and forest in the mountains you are often lucky to get GPS precision better than 60m. Stop saying GPS. Forget even about aerial imagery. When I had no aerial imagery in my area, I either did not draw such features (leaving them for future improvements), or approximate. The road there is about 6 meters wide, so I'll draw two nodes about 6 meters apart, split the waterway there and tag the middle piece as a culvert. It's not that hard, it's not that much imprecise, sure it may be improved with better measurements, but it is not wrong, especially it is not topologically wrong. Regards, Simone ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 4/4/14 5:51 AM, Simone Saviolo wrote: Stop saying GPS. Forget even about aerial imagery. When I had no aerial imagery in my area, I either did not draw such features (leaving them for future improvements), or approximate. The road there is about 6 meters wide, so I'll draw two nodes about 6 meters apart, split the waterway there and tag the middle piece as a culvert. It's not that hard, it's not that much imprecise, sure it may be improved with better measurements, but it is not wrong, especially it is not topologically wrong. and if you are not sure about the extent of the structure or its nature there's no harm in nipping out a short section, setting layer=1 and skipping the other tagging (bridge=yes or whatever.) you have accurately represented what you know and maintained correct topology. richard -- rwe...@averillpark.net Averill Park Networking - GIS IT Consulting OpenStreetMap - PostgreSQL - Linux Java - Web Applications - Search signature.asc Description: OpenPGP digital signature ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Richard Welty wrote: and if you are not sure about the extent of the structure or its nature there's no harm in nipping out a short section, setting layer=1 and skipping the other tagging (bridge=yes or whatever.) you have accurately represented what you know and maintained correct topology. ... providing there's a QA site that will continue to flag that as an error. The fact that a QA site flags an error is good if something isn't correct; it means that someone can go and have a look and map it properly. Another option would be to add an OSM note, I guess. We sometimes forget that the aim is to have data that actually represents the world, not data that generates no errors on QA sites Cheers, Andy ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-03 1:53 GMT+02:00 Janko Mihelić jan...@gmail.com: Rationale in the Wiki says this would save us database space, we would have 2 ways and 1 node less per bridge. Also, that maintaining one node is easier than maintaining 3 ways. Lastly, problem of pretending you have drawn a little bridge precise, when you didn't. All of these are valid points, FWIW, it is not true, we would save 1 way or 2, but the amount of nodes would remain the same, because with the new proposal the waterway would get an extra node which it hasn't otherwise. The 1 way saved is on the other hand loss of information as pointed out before. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Whilst I think this is a very bad idea for the same reasons as already given by Martin and Janko. What on earth is a Brunnel? I don't know and neither does google. I have an idea from reading the thread but I wonder how many have ignored the thread through the choice of words in the title? Phil (trigpoint) -- Sent from my Nokia N9 On 03/04/2014 10:12 Martin Koppenhoefer wrote: 2014-04-03 1:53 GMT+02:00 Janko Mihelić jan...@gmail.com: Rationale in the Wiki says this would save us database space, we would have 2 ways and 1 node less per bridge. Also, that maintaining one node is easier than maintaining 3 ways. Lastly, problem of pretending you have drawn a little bridge precise, when you didn't. All of these are valid points, FWIW, it is not true, we would save 1 way or 2, but the amount of nodes would remain the same, because with the new proposal the waterway would get an extra node which it hasn't otherwise. The 1 way saved is on the other hand loss of information as pointed out before. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-03 11:12 GMT+02:00 Martin Koppenhoefer dieterdre...@gmail.com: FWIW, it is not true, we would save 1 way or 2, but the amount of nodes would remain the same, because with the new proposal the waterway would get an extra node which it hasn't otherwise. The 1 way saved is on the other hand loss of information as pointed out before. I went super-geeky, and made a quick estimation of xml size: http://pastebin.com/ZDXPv8fK I don't know if the database sizes are proportional to xml, but there's 674 letters in the brunnell version, and 1306 letters in the bridge version of the xml. So more than double :) Waterway only refers the same node. Janko ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 02/04/2014 17:14, Richard Z. wrote: as explained in the rationale the dimensions of the bridge/culvert are frequently only a fraction of the achievable precision. Think of a track crossing a small creek in a forest valley int the mountains. The GPS precision will be 10 meters if you are lucky, the brunnel 2-3m. Mapping this the old fashioned way will produce junk data, not precision. Rubbish. Please don't rely on a GPSr. It is only one, of many, ways to survey. If I see a small bridge over a stream, say 3m I'll map is as that, because that's how it accurately is in the real world. Some users have access to detailed aerial imagery to help map accurately. David Fox --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Mike We should be mapping as accurately as we can within the limitations (gps accuracy, aerial imagery etc) that we have. Data can always be upgraded when more accurate information becomes available. This proposal is a step backwards towards inaccuracy. On 02/04/2014 18:29, Mike Thompson wrote: We aim at precision/accuracy (IMHO, at least I do), 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. 2) In general, there is a cost to increased precision (and accuracy) in terms of the survey effort, the survey equipment, the recording effort, and the computing resources. 3) At some point the value of increased precision ceases to grow, and may even decline. On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer dieterdre...@gmail.com mailto:dieterdre...@gmail.com wrote: 2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com mailto:miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org mailto:Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 06:08:46PM +0100, Dave F. wrote: On 02/04/2014 17:14, Richard Z. wrote: as explained in the rationale the dimensions of the bridge/culvert are frequently only a fraction of the achievable precision. Think of a track crossing a small creek in a forest valley int the mountains. The GPS precision will be 10 meters if you are lucky, the brunnel 2-3m. Mapping this the old fashioned way will produce junk data, not precision. Rubbish. Please don't rely on a GPSr. It is only one, of many, ways to survey. If I see a small bridge over a stream, say 3m I'll map is as that, because that's how it accurately is in the real world. Some users have access to detailed aerial imagery to help map accurately. so again: *** a small creek in a forest valley int the mountains *** Where is your aerial imagery? I want that!! In the mountains you are very lucky if your imagery has less than 10 meter offset and forests render most aerial imagery useless. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 01:53:15AM +0200, Janko Mihelić wrote: Also -1 for the proposal. Rationale in the Wiki says this would save us database space, we would have 2 ways and 1 node less per bridge. Also, that maintaining one node is easier than maintaining 3 ways. Lastly, problem of pretending you have drawn a little bridge precise, when you didn't. All of these are valid points, but I think they don't overweight the problems this would give us. We would break one of the most basic rules we have, and we don't have much rules. this basic rule seems to spook around here and I think we should look at it. So what is it? We don't know what that could hurt. we have an idea. There are some 10,000 single node bridges in OSM data already. Some share of those does also share a node with the waterway bellow and not all of them are in exotic locations where nobody would ever notice. Second are mappers who like clear rules. And if we don't have those core rules, future may bring us problems. are the rules for the proposal unclear? Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Wed, Apr 02, 2014 at 07:44:40PM +0200, Tobias Knerr wrote: On 02.04.2014 18:14, Richard Z. wrote: On Wed, Apr 02, 2014 at 05:59:40PM +0200, Martin Koppenhoefer wrote: IMHO there is a fundamental problem to your proposal because you want to connect 2 ways with a node which are in reality disjunct objects connected with pylons and lifts are also disjunct. So what? Don't dismiss that argument so casually. The current rule is that the way below the bridge should not share a node with the bridge itself. the current idea that culverts float bellow roads without having anything common with them is not correct in most cases. These culverts are part of an integral highway-culvert-waterway construction. The same is true for most bridges, only a small fraction does float independently above valeys but most are connected with the lower way by the actual bridge construction. I could imagine adding an exception to that rule if it were hard to avoid a shared node. But in this case, it can very easily be avoided by mapping the bridge in the same manner two million other bridges have already been added: as a way. easily? So you have biked 60 miles along a forest track and know reliably that there was not a single ford on your route today. You look at OSM data in the evening and see there are 120 streams which you crossed with missing bridges/culverts. What do you do? Leave those 120 crossings in incomplete state even though someone might be really interested to know whether there are some fords on the way? Add fictional bridges or culverts? Say ford=no? The other point - even if you know it is a bridge or culvert - is it worth painting an insignificant structure which is perhaps 3m in size when the GPS error is more likely 10 meters? In a deep valley and forest in the mountains you are often lucky to get GPS precision better than 60m. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 09:52:13PM +0200, Martin Koppenhoefer wrote: Am 03/apr/2014 um 21:43 schrieb Richard Z ricoz@gmail.com: so again: *** a small creek in a forest valley int the mountains *** Where is your aerial imagery? I want that!! you don't need imagery, you simply draw a segment with the approx. length of the bridge. If you have no reliable sources, putting a node won't make this more accurate neither. That's not an argument for softening the topology rules. at least a node won't pretend pecision which is not there. We have dams, fords, weirs as either node or way. It is normal to map them as a single node for smaller structures and as way when they are worth it. Why not bridges? https://wiki.openstreetmap.org/w/index.php?title=Topology_rulesaction=editredlink=1 I think that page is waiting to be written. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 09:53:44AM +, Philip Barnes wrote: Whilst I think this is a very bad idea for the same reasons as already given by Martin and Janko. What on earth is a Brunnel? I don't know and neither does google. I have an idea from reading the thread but I wonder how many have ignored the thread through the choice of words in the title? A brunnel is a crossbreed of a bridge with a tunnel. It has been used somewhere to describe constructions where it is not easy to decide whether a grade separated crossing is better described as a tunnel under a road or bridge above something. The distinction between bridge and tunnel variant is somewhat arbitrary, very often completely uninteresting - and in many cases the construction is really something of a mix of a bridge and tunnel. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Yes, one reason to reject this is that it involves a neologism, coined by the proposal author, that few people will recognize and use. On April 3, 2014 4:53:44 AM CDT, Philip Barnes p...@trigpoint.me.uk wrote: Whilst I think this is a very bad idea for the same reasons as already given by Martin and Janko. What on earth is a Brunnel? I don't know and neither does google. I have an idea from reading the thread but I wonder how many have ignored the thread through the choice of words in the title? Phil (trigpoint) -- Sent from my Nokia N9 On 03/04/2014 10:12 Martin Koppenhoefer wrote: 2014-04-03 1:53 GMT+02:00 Janko Mihelić jan...@gmail.com: Rationale in the Wiki says this would save us database space, we would have 2 ways and 1 node less per bridge. Also, that maintaining one node is easier than maintaining 3 ways. Lastly, problem of pretending you have drawn a little bridge precise, when you didn't. All of these are valid points, FWIW, it is not true, we would save 1 way or 2, but the amount of nodes would remain the same, because with the new proposal the waterway would get an extra node which it hasn't otherwise. The 1 way saved is on the other hand loss of information as pointed out before. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Dr. Martin Luther King, Jr. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Thu, Apr 03, 2014 at 12:07:42PM +0200, Janko Mihelić wrote: 2014-04-03 11:12 GMT+02:00 Martin Koppenhoefer dieterdre...@gmail.com: FWIW, it is not true, we would save 1 way or 2, but the amount of nodes would remain the same, because with the new proposal the waterway would get an extra node which it hasn't otherwise. The 1 way saved is on the other hand loss of information as pointed out before. I went super-geeky, and made a quick estimation of xml size: http://pastebin.com/ZDXPv8fK I don't know if the database sizes are proportional to xml, but there's 674 letters in the brunnell version, and 1306 letters in the bridge version of the xml. So more than double :) Waterway only refers the same node. thanks. I suspect the difference would be more substantial if the bridge would carry several hiking routes or you want to put a waterway into a culvert which happens to share way with 3 admin boundaries? Also, it is frequent practice to anchor the other way which would add other (up to) two completely useless nodes. More than database size the other issues bug me much more: * we pretend a level of precision which is not there and knowingly enter junk data into the database. * the resulting structure is more difficult to cleanup and maintain than a single node Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
That is my main objection as well. This proposal is to deliberately reduce the accuracy of the data in the name of saving a few seconds of mapping time. On April 3, 2014 12:25:46 PM CDT, Dave F. dave...@madasafish.com wrote: Mike We should be mapping as accurately as we can within the limitations (gps accuracy, aerial imagery etc) that we have. Data can always be upgraded when more accurate information becomes available. This proposal is a step backwards towards inaccuracy. On 02/04/2014 18:29, Mike Thompson wrote: We aim at precision/accuracy (IMHO, at least I do), 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. 2) In general, there is a cost to increased precision (and accuracy) in terms of the survey effort, the survey equipment, the recording effort, and the computing resources. 3) At some point the value of increased precision ceases to grow, and may even decline. On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer dieterdre...@gmail.com mailto:dieterdre...@gmail.com wrote: 2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com mailto:miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org mailto:Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Dr. Martin Luther King, Jr. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 03/04/2014 22:04, Richard Z. wrote: A brunnel is a crossbreed of a bridge with a tunnel. It has been used somewhere to describe constructions where it is not easy to decide whether a grade separated crossing is better described as a tunnel under a road or bridge above something. Really? Are you sure you're not just making this up? Show us where or I'm calling you a fibber. Dave F. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 03/04/2014 22:05, John F. Eldredge wrote: Yes, one reason to reject this is that it involves a neologism, coined by the proposal author, that few people will recognize and use. I think he's getting confused with I.K. Brunel ;-) Dave F. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 04:27:57PM -0500, John F. Eldredge wrote: That is my main objection as well. This proposal is to deliberately reduce the accuracy of the data in the name of saving a few seconds of mapping time. nonsense. This proposal is here to improve the accuracy. You do not have to use when you have precise data about bridge position and size. On the other hand if your data is of the average precision (i.e. 5 meter GPS error) and you try to enter a 3m bridge into the database you are entering junk data. This is the situation when less data is better because it means less junk data in effect. Richard On April 3, 2014 12:25:46 PM CDT, Dave F. dave...@madasafish.com wrote: Mike We should be mapping as accurately as we can within the limitations (gps accuracy, aerial imagery etc) that we have. Data can always be upgraded when more accurate information becomes available. This proposal is a step backwards towards inaccuracy. On 02/04/2014 18:29, Mike Thompson wrote: We aim at precision/accuracy (IMHO, at least I do), 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. 2) In general, there is a cost to increased precision (and accuracy) in terms of the survey effort, the survey equipment, the recording effort, and the computing resources. 3) At some point the value of increased precision ceases to grow, and may even decline. On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer dieterdre...@gmail.com mailto:dieterdre...@gmail.com wrote: 2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com mailto:miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org mailto:Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Dr. Martin Luther King, Jr. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Thu, Apr 03, 2014 at 10:49:56PM +0100, Dave F. wrote: On 03/04/2014 22:04, Richard Z. wrote: A brunnel is a crossbreed of a bridge with a tunnel. It has been used somewhere to describe constructions where it is not easy to decide whether a grade separated crossing is better described as a tunnel under a road or bridge above something. Really? Are you sure you're not just making this up? Show us where or I'm calling you a fibber. How much more stupid do you want to get if you don't use the basic search function. http://wiki.openstreetmap.org/wiki/Advanced_relationships http://wiki.openstreetmap.org/wiki/Key:layer Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 03/04/2014 22:58, Richard Z. wrote: On Thu, Apr 03, 2014 at 04:27:57PM -0500, John F. Eldredge wrote: That is my main objection as well. This proposal is to deliberately reduce the accuracy of the data in the name of saving a few seconds of mapping time. nonsense. This proposal is here to improve the accuracy. You do not have to use when you have precise data about bridge position and size. On the other hand if your data is of the average precision (i.e. 5 meter GPS error) and you try to enter a 3m bridge into the database you are entering junk data. This is the situation when less data is better because it means less junk data in effect. No. If you have a GPS/GPX trace you must have been there seen it. So don't rely on your hardware, use your eyes! A bridge with two nodes way will always be more accurate (note: not necessarily completely accurate) than a node. We're mapping physical objects from the real world as accurately as we can. David F. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 03/04/2014 23:06, Richard Z. wrote: On Thu, Apr 03, 2014 at 10:49:56PM +0100, Dave F. wrote: On 03/04/2014 22:04, Richard Z. wrote: A brunnel is a crossbreed of a bridge with a tunnel. It has been used somewhere to describe constructions where it is not easy to decide whether a grade separated crossing is better described as a tunnel under a road or bridge above something. Really? Are you sure you're not just making this up? Show us where or I'm calling you a fibber. How much more stupid do you want to get if you don't use the basic search function. http://wiki.openstreetmap.org/wiki/Advanced_relationships http://wiki.openstreetmap.org/wiki/Key:layer No, I meant in the real world. A dictionary entry? A Google image? Anybody can edit a wiki page type in junk as you like to call it. Dave F. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 4/3/14 6:06 PM, Richard Z. wrote: On Thu, Apr 03, 2014 at 10:49:56PM +0100, Dave F. wrote: Really? Are you sure you're not just making this up? Show us where or I'm calling you a fibber. How much more stupid do you want to get if you don't use the basic search function. http://wiki.openstreetmap.org/wiki/Advanced_relationships http://wiki.openstreetmap.org/wiki/Key:layer umm, the term only seems to appear here. google does not find any references to it. from this i have to assume that the term brunnel is something that was proposed and maybe even standardized, but never gained traction. i am not persuaded by the arguments for this tagging scheme. richard -- rwe...@averillpark.net Averill Park Networking - GIS IT Consulting OpenStreetMap - PostgreSQL - Linux Java - Web Applications - Search signature.asc Description: OpenPGP digital signature ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 03/04/14 23:27, Richard Welty wrote: On 4/3/14 6:06 PM, Richard Z. wrote: http://wiki.openstreetmap.org/wiki/Advanced_relationships http://wiki.openstreetmap.org/wiki/Key:layer umm, the term only seems to appear here. google does not find any references to it. from this i have to assume that the term brunnel is something that was proposed and maybe even standardized, but never gained traction. The only sense in which I remember it being used in the real world is this one: http://www.csmonitor.com/1984/1204/120446.html/%28page%29/2 As in, a crossing scheme for e.g. the English Channel comprising both bridge and tunnel - not the thing that seems to be being proposed here at all. Cheers, Andy ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
[Tagging] simple_brunnel : one node bridge like xing highway over waterway
Hi, I have something revolutionary simple in my sleeve for the case where a highway is going over a waterway: https://wiki.openstreetmap.org/wiki/Talk:Key:bridge#Simple_one-node_brunnels_for_way_over_waterway We have been thinking about it for a while and it seems there is some demand which could justify it. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-02 16:41 GMT+02:00 Richard Z. ricoz@gmail.com: have something revolutionary simple in my sleeve for the case where a highway is going over a waterway: https://wiki.openstreetmap.org/wiki/Talk:Key:bridge#Simple_one-node_brunnels_for_way_over_waterway We have been thinking about it for a while and it seems there is some demand which could justify it. you mean, let's go a step back if we can't convince really everybody to map according to the standards? ;-) IMHO there is a fundamental problem to your proposal because you want to connect 2 ways with a node which are in reality disjunct (and then you will fix it with a tag that explains that there is no connection). I do not believe that this will make things easier, my guess is that inventing exceptions like this will confuse mappers and blur the idea of our topological model. It is also a significant loss of detail because you reduce the length of the bridge to 0. cheers, Martin ___ You call it brunnel, I'd call it tudge ;-) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On Wed, Apr 02, 2014 at 05:59:40PM +0200, Martin Koppenhoefer wrote: 2014-04-02 16:41 GMT+02:00 Richard Z. ricoz@gmail.com: have something revolutionary simple in my sleeve for the case where a highway is going over a waterway: https://wiki.openstreetmap.org/wiki/Talk:Key:bridge#Simple_one-node_brunnels_for_way_over_waterway We have been thinking about it for a while and it seems there is some demand which could justify it. you mean, let's go a step back if we can't convince really everybody to map according to the standards? ;-) there is more to the motivation if you read the RATIONALE part. IMHO there is a fundamental problem to your proposal because you want to connect 2 ways with a node which are in reality disjunct objects connected with pylons and lifts are also disjunct. So what? It is also a significant loss of detail because you reduce the length of the bridge to 0. as explained in the rationale the dimensions of the bridge/culvert are frequently only a fraction of the achievable precision. Think of a track crossing a small creek in a forest valley int the mountains. The GPS precision will be 10 meters if you are lucky, the brunnel 2-3m. Mapping this the old fashioned way will produce junk data, not precision. Richard ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. In most cases we already reduce the width of roads to 0 as they are not represented by areas. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. Mike On Wed, Apr 2, 2014 at 9:59 AM, Martin Koppenhoefer dieterdre...@gmail.comwrote: 2014-04-02 16:41 GMT+02:00 Richard Z. ricoz@gmail.com: have something revolutionary simple in my sleeve for the case where a highway is going over a waterway: https://wiki.openstreetmap.org/wiki/Talk:Key:bridge#Simple_one-node_brunnels_for_way_over_waterway We have been thinking about it for a while and it seems there is some demand which could justify it. you mean, let's go a step back if we can't convince really everybody to map according to the standards? ;-) IMHO there is a fundamental problem to your proposal because you want to connect 2 ways with a node which are in reality disjunct (and then you will fix it with a tag that explains that there is no connection). I do not believe that this will make things easier, my guess is that inventing exceptions like this will confuse mappers and blur the idea of our topological model. It is also a significant loss of detail because you reduce the length of the bridge to 0. cheers, Martin ___ You call it brunnel, I'd call it tudge ;-) ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
We aim at precision/accuracy (IMHO, at least I do), 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. 2) In general, there is a cost to increased precision (and accuracy) in terms of the survey effort, the survey equipment, the recording effort, and the computing resources. 3) At some point the value of increased precision ceases to grow, and may even decline. On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non- links) if not added explicitly. A bridge that is a single node could also have a tag for length (as well as one for width). I am not suggesting this, just pointing out that tags could be added to other geometries to denote additional dimensions. The point is we have chosen to use geometry that does not have width to represent a real world object that does. Also, in many cases the width tag is is not used on roads. On Wed, Apr 2, 2014 at 11:29 AM, Mike Thompson miketh...@gmail.com wrote: We aim at precision/accuracy (IMHO, at least I do), 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. 2) In general, there is a cost to increased precision (and accuracy) in terms of the survey effort, the survey equipment, the recording effort, and the computing resources. 3) At some point the value of increased precision ceases to grow, and may even decline. On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer dieterdre...@gmail.com wrote: 2014-04-02 18:16 GMT+02:00 Mike Thompson miketh...@gmail.com: It is also a significant loss of detail because you reduce the length of the bridge to 0 Maps are abstractions. They don't represent reality precisely. We aim at precision/accuracy (IMHO, at least I do), you can always create more abstracted maps from precise geodata, while the other way round it is not possible. In most cases we already reduce the width of roads to 0 as they are not represented by areas. no, their geometric representation is a line, but their width is (or can be) added with a tag like width and lanes, of which the latter defaults to 2 (for non-links) if not added explicitly. The question should be whether the value of the data is significantly degraded if some very short bridges are represented as nodes. OK. Can you explain how long a very short bridge should be? What is the benefit of this kind of mapping style? In this context I'd like to point out that GPS precision is not the limit, you do not have to take 2 waypoints at the beginning and end of the bridge and the result will become your bridge, automatically, usually you will interpret these waypoints and will estimate the bridge length and represent it according to your estimate, so I do not think a 3 meters long bridge will result in a 45 meters long zigzag in your mapping, just because you had bad GPS reception under the tree canopy and made a break on the bridge ;-) cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
On 02.04.2014 18:14, Richard Z. wrote: On Wed, Apr 02, 2014 at 05:59:40PM +0200, Martin Koppenhoefer wrote: IMHO there is a fundamental problem to your proposal because you want to connect 2 ways with a node which are in reality disjunct objects connected with pylons and lifts are also disjunct. So what? Don't dismiss that argument so casually. The current rule is that the way below the bridge should not share a node with the bridge itself. I could imagine adding an exception to that rule if it were hard to avoid a shared node. But in this case, it can very easily be avoided by mapping the bridge in the same manner two million other bridges have already been added: as a way. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-02 19:29 GMT+02:00 Mike Thompson miketh...@gmail.com: 1) How much precision/accuracy? No real world measurement or recording of such measurement is exactly precise/accurate. Do you use a commercial grade differential GPS when surveying? When you are create a way to represent a road which in reality is an arc or curve, how many nodes do you use? You could increase your precision by adding more nodes. more than positional precision I try to achieve relative accuracy, e.g. the position of a building in respect to another, the shape of something (e.g. if the road is straight, I do not put intermediate points), if a feature is linear I do not represent it as a node, etc. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
2014-04-02 19:40 GMT+02:00 Mike Thompson miketh...@gmail.com: A bridge that is a single node could also have a tag for length (as well as one for width). yes, but it would not tell you how they are oriented, because a node has no direction, it is a point. cheers, Martin ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
At a road intersection, vehicle can interchange. At a railroad intersection only one mode can use the way at a time. A river/highway crossing is not an intersection. The stream does not stop for traffic. These features should not share nodes, no mater how they are tagged. I see no problem with a rule that says streams have implicitly lower precedence than highways: then only exceptions like dry washes need be tagged. The only case where I'd created a junction between stream and highway is for an arroyo, where in fact only one way can be used at a time (either the stream is at low flow or the roadway is impassable). -1 on the proposal. ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
Re: [Tagging] simple_brunnel : one node bridge like xing highway over waterway
Also -1 for the proposal. Rationale in the Wiki says this would save us database space, we would have 2 ways and 1 node less per bridge. Also, that maintaining one node is easier than maintaining 3 ways. Lastly, problem of pretending you have drawn a little bridge precise, when you didn't. All of these are valid points, but I think they don't overweight the problems this would give us. We would break one of the most basic rules we have, and we don't have much rules. We don't know what that could hurt. One example are renderers who should learn how to render bridges with one point. Second are mappers who like clear rules. And if we don't have those core rules, future may bring us problems. Maybe the biggest problem with this proposal is the feeling I got as soon as I understood you wanted to map bridges as nodes. It felt wrong, and I think a lot of mappers will feel the same way. Janko ___ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
