Re: [OSM-talk] fwd: Two thirds of mobile users want driving ANDwalking navigation
On Tue, 16 Feb 2010 18:29:10 + Graham Jones grahamjones...@googlemail.com wrote: You are both right. RF absorption is a combination of amount of material and its properties. I think the issue with trains is limited to newer ones with special windows (I think they are conductive - some cars have them too). The combination of shielding from the roof and windows makes it practically impossible to get a fix. I was surprised that I managed to get a fix in a jet aircraft a few months ago - I would have expected this to be a good shield too. [...] You were probably sitting in a window seat, right? Getting a fix from a window seat is usually not a problem, but I was not able to get a fix elsewhere. I have tracks from several flights in India. As long as the windows are glass, or transparent to radio-frequency waves, the GPS signal will diffract in, as the wavelength is much larger than the size of the window. However, there are probably issues like reflections within the cabin, how many satellites are visible from the window, etc. Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [Talk-in] GPS purchase
On Sat, 23 Jan 2010 07:58:08 +0530 H.S.Rai hardeep@gmail.com wrote: For Joint Punjab Mapping Project I need to purchase 10 units GPS Data Loggers. Please suggest which make and model I should buy. http://wiki.openstreetmap.org/wiki/GPS_Reviews , just in case you are not aware of it. We tried out several models, and were happy with the Holux, the Globalsat DG-100, and the Amod AGL-3080 (all chosen through the above Wiki page). All of these are loggers, and do not have maps. If I remember correctly, the latter two have significantly higher storage capacity. You could just opt to order from the US. We have been very happy with http://www.semsons.com/ . Even with shipping costs, each of the above came to about $65-70/unit. My foremost requirement is to get transferred data (GPS logs, WayPoints) from units to Linux loaded PC / Laptop. Till date I have used Garmin GPSmap 76CSx, Garmin eTrex H, Garmin Geko 201, RoyalTek GPS Data Logger RBT2300. For all above except 76CSx, I have to use M$ windows to get data transferred [...] That is strange. Most GPS units can nowadays be made to work with Linux, with exceptions of course. If you can let us borrow a unit for a few days, we would be glad to have a go at it. Regards, Gora ___ Talk-in mailing list Talk-in@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-in
Re: [Talk-in] anything during this FOSS.IN?
On Sun, 25 Oct 2009 21:19:09 +0530 Subhodip Biswas subhodipbis...@gmail.com wrote: Hi! Is the community planning something during this FOSS.IN. Workouts/Workshops/BoF's/Talks? [...] Not sure if anyone has submitted anything, and am also not sure what could be covered in a talk or a workout. If you are going to be at the meeting, we can do an informal BoF set up then and there. Regards, Gora ___ Talk-in mailing list Talk-in@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-in
Re: [Talk-in] anything during this FOSS.IN?
On Sun, 25 Oct 2009 22:25:05 +0530 Srikanth Lakshmanan srik@gmail.com wrote: On Sun, Oct 25, 2009 at 10:15 PM, Gora Mohanty g...@sarai.net wrote: Not sure if anyone has submitted anything, and am also not sure what could be covered in a talk or a workout. If you are going to be at the meeting, we can do an informal BoF set up then and there. Mini Mapping Party? NIMHANS is blank on OSM. Not sure if it will get accepted though. If you are interested, go ahead and submit it (the deadline is midnight tomorrow, Mon.). Whether it is accepted or not, we can just do it any way. Regards, Gora ___ Talk-in mailing list Talk-in@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-in
Re: [OSM-talk] 'Distance to feature' maps?
On Wed, 15 Jul 2009 13:30:44 -0400 (EDT) si...@mungewell.org wrote: only needs an dijkstra algorithm and some more lines of code. sounds so simple... ;-) I had a look at the wikipedia page (http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm) and that would look to make sense. Actually, an implementation of the Dijkstra algorithm is not difficult at all. When we were trying to do this with Python and Django, we came across a couple of sample implementations. Better yet, there is the Boost graph library which already implements the Dijkstra shortest path algorithm. The library is in C++, but there are various bindings to it. To push our own work, one can take a look at an implementation at http://citybyroad.com/ (Log in with user/password testuser/ gpstrack). This actually was a more ambitious attempt to get shortest paths based on actual travel time from GPS traces. However, ignore that for the moment, and also ignore the half- completed state of the application. Leave all the drop-down boxes as Unspecified, enter a from/to address via the auto- complete boxes (try Raja Puri and Srijan Technologies, allowing the auto-complete to take over after typing a few letters), and click on the blue FIND ROUTE button. The result shown on the map is from the Dijkstra shortest-path algorithm, based on distance. The distance is calculated by integrating along known routes, which is a fairly tedious, manual process, but OSM routes should already have that information. For someone familiar with Delhi, the application will be unable to find some routes, as the database is not completely populated. As you may have noticed I've actually had a relatively amount of success with this, but my brain is off on the 'multiple targets' question. Is it valid to repeat the dijkstra algorithm with multiple 'target' nodes, so you could find the shortest path to (say) any playground? Target nodes could auto-magically be extracted from OSM file based on tags. [...] Does this sound correct? Your description covers the gist of the issue. The Dijkstra algorithm actually visits every node in the network, and thus running it once between two points should find all shortest paths. In practice, it seems that the Boost implementation prunes unlikely paths, so that one has to start with two extreme points, and maybe rerun the algorithm a couple more times with other extreme points in order to get full coverage. Came into this conversation a little late, but if you had a definite purpose in mind, we would be glad to share the code, and maybe even put in some work on a reimplementation. What language are you planning on using? Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [Talk-in] February trip
On Mon, 16 Feb 2009 23:25:33 +0530 Shajeer Mohammed shaj...@hotmail.com wrote: Here is page of ECI that has shape files for assembly and parliament constituencies here (Thanks to PradeepBV) Each sate is in a separate file and all the polygons can be merged to get a state by state outline http://www.eci.gov.in/GisLayers/gis_layers.asp Thanks. Will look into this. I also have country/state/district data for India from a free site, but there were no clear licensing terms. They have put the license terms here http://www.eci.gov.in/DevForum/DevForum.asp Any thoughts on importing this to OSM? IMHO, the licensing terms need to be clarified, as the above page says is being put in Public Domain under MIT Style License, which is a little too vague for my taste. I will try talking to some contacts in the Election Commission. Regards, Gora ___ Talk-in mailing list Talk-in@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-in
Re: [OSM-talk] bengali on my JOSM won't work
On Sat, 31 Jan 2009 12:38:20 +0530 Vikas Yadav vikas.ya...@threebrix.com wrote: Hi, I was trying to add name:bn: কলকাতা to KolKata/Calcutta but JOSM shows me boxes. I install all fonts and my gedit renders correctly and also the browser (the wikipedia page for kolkata where I took the translation from). Please help. [...] It is almost certainly an issue with the locales supported by Java. You will probably find that Hindi works. Which java are you using (try java -version)? For Sun java, a list of supported locales might be found at one of these places (for a different Sun Java version, try changing the version number in the URL): 1.4.2: http://java.sun.com/j2se/1.4.2/docs/guide/intl/locale.doc.html 1.5.0: http://java.sun.com/j2se/1.5.0/docs/guide/intl/locale.doc.html java6: http://java.sun.com/javase/6/docs/technotes/guides/intl/locale.doc.html Don't know Java well enough to tell if other locales can be added. Your other alternative is to use Potlatch. Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] mkcntr2.pl: perl hackers wanted to fix contours....
On Fri, 22 Aug 2008 14:53:23 -0400 (EDT) [EMAIL PROTECTED] wrote: [...] I'd love to make the changes myself, but perl is about as foreign a language as could be. My suggestion is that a couple of extra parameters are add to mark 'elevation_medium' and 'elevation_major' contours. For example: mkcntr2.pl extract.txt 10 50 100 contours.osm would produce minor contours at 10m separations, medium at multiples of 50m and major at multiples of 100m. [...] OK, had a look at the requirements, and the Perl script, so this looks like it ought to be easy to do. I have made an example extract.txt file using the directions in applications/utils/import/srtm2osm. As I am new to OSM, and the tagging mechanism used, can you send me off-list a short example of what contours.osm should look like? Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] weird behaviour of a gps instrument
On Mon, 4 Aug 2008 12:15:24 +0530 Kenneth Gonsalves [EMAIL PROTECTED] wrote: One suggestion is that the instrument is picking up some other signals from other satellites. Has anyone experienced anything like this? Is shadowing, or multiple reflections from the terrain possible. The other possibility is electromagnetic interface, the GPS signal being radio-frequency after all. Might even be deliberate if it is a militarily-sensitive area. How precise is the 0.1 deg.? Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Importing from Geonames.org
On Wed, 18 Jun 2008 08:25:24 +0100 Andy Robinson \(blackadder-lists\) [EMAIL PROTECTED] wrote: Simon Wood wrote: Sent: 18 June 2008 7:31 AM To: talk@openstreetmap.org Subject: [OSM-talk] Importing from Geonames.org There's a comment on the wiki that Geonames.org may be tainted data is this true or false? Tainted in what way? Are there copyright issues? There are 256 towns/villages/hamlets missing from Alberta (as compaired to the official lists). Geonames appears to have lat/long for a fair proportion of these. If the geoname data is OK, I will set about importing these/generating nodes for them. [...] The other problem that I have noticed with the geonames database is that the latitude, longitude for places in Delhi, India, are wrong. This is apparently a known issue, and we will try to contribute fixed positions back to geonames. Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] Cooperative Differential GPS
(Please note that I am copying this message to the OpenStreetMap folk: http://openstreetmap.org as we will hopefully find more GPS/mapping experts there. Please edit the list of recipients if you need to.) On Thu, 27 Mar 2008 14:24:56 +0100 [EMAIL PROTECTED] wrote: Hi all! After hours of searching the web for information about the new Antaris GPS chip I am still not sure if it will be possible to use the raw data output of the ATR0635 (message type RXM-RAW) on the Neo FreeRunner. This message should, according to the protocol specification [1], contain information about the per-satellite errors necessary to build something like a cooperative differential GPS [2]. Such an application could - in theory - greatly improve the accuracy of the Neo-GPS and therefore open it up to a whole new range of use-cases. [...] Thanks for bringing this up, as this is is a topic that I am very much interested in. We are just starting to explore this area, but the AGPS capabilities of the Neo 1973 was one reason that we went ahead and bought this. However, I do not know what AGPS support means in real terms. My naive understanding of this is that a cooperative differential GPS needs no external support. One just sits at a base station, and averages GPS readings until one knows the position of the base station to an arbitrary level of accuracy. After that, the reception of realtime GPS signals at the base station provides information about random errors, which I understand are largely due to atmospheric fluctuations. Corrections for these are derived from the difference between the well-known actual position of the base station, and the received realtime position. These can be broadcast through various means, e.g., an Internet DGPS server, and should be good for a few hundred km around the base station. The cooperative aspect of this comes in because of the benefits of multiple base stations. I would love to be corrected on the above by someone who knows better, as this is little more than a surmise on how DGPS should work. Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
Re: [OSM-talk] Stares
On Tue, 11 Mar 2008 13:34:56 - Andy Robinson \(blackadder\) [EMAIL PROTECTED] wrote: [...] Luckily I've never really had any major trouble but my standard response would probably be Got the internet? Look up www.openstreetmap.org. Is your street on there and named? No? Will it soon will be... +1 to this approach. I often get people looking at me on a Sunday morning while they wash their cars and I always make a point of saying good morning or whatever. If someone does ask a question I do exactly as Nick suggests. There is no need for OSM data gathering to be a subversive activity. Make a statement about it and tell people what you are doing. [...] With all due respect, while I agree with the general tenor of this message, and am completely in favour of an open explanation, and negotiation of what is acceptable in the public sphere, I am also quite prickly at protecting what I perceive as *my* right in this regard. In my opinion, the more one retreats in this regard, the more the forces of fascism^W anti-terrorism are going to push one. I am doing nothing wrong, and should *not* have to explain myself to anyone under duress. I agree that there is a fine line there---one which is applicable to both sides---but the more that people meet me with a confrontational approach, the more likely I am to push back. Fortunately, I am very rarely faced with such an eventuality, but other, less respectable-looking, people might be. You speak about the Internet, and openstreetmap.org, but talk about these with most people in India, and you will be met with a blank stare. Better hope that you do not look like you belong in the quote torturable class unquote. Regards, Gora ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
