[Flightgear-devel] radio towers (in the default scenery, and in general)
hi. the radio towers introduced all over the place in the new scenery build don't appear to be present in the copy of the default area that's in CVS. if i use the data rsync'd from Scenery-0.9.5 for the default area, they're all over the place; but in the copy from CVS, they aren't. is their use going to be rolled back? or is the CVS scenery not yet from the new build, and they'll be there later? Just curious. And while asking about the radio towers . . .my (perhaps wrong) understanding is that they come from some sort of FAA obstruction database; that's why some are at locations where large buildings are located in real life. Is that correct? If so, why not use the FCC's Antenna Structure Registration database (http://wireless.fcc.gov/antenna/) instead? -c -- Chris Metzler [EMAIL PROTECTED] (remove snip-me. to email) As a child I understood how to give; I have forgotten this grace since I have become civilized. - Chief Luther Standing Bear pgpySDYGm1AvT.pgp Description: PGP signature ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Chris Metzler wrote: hi. the radio towers introduced all over the place in the new scenery build don't appear to be present in the copy of the default area that's in CVS. if i use the data rsync'd from Scenery-0.9.5 for the default area, they're all over the place; but in the copy from CVS, they aren't. is their use going to be rolled back? or is the CVS scenery not yet from the new build, and they'll be there later? Just curious. The CVS included scenery is an updated version of the FlightGear-0.9.3 scenery. It has to be updates at some time. Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Chris Metzler wrote: And while asking about the radio towers . . .my (perhaps wrong) understanding is that they come from some sort of FAA obstruction database; that's why some are at locations where large buildings are located in real life. Is that correct? If so, why not use the FCC's Antenna Structure Registration database (http://wireless.fcc.gov/antenna/) instead? We are actually using the fcc database, however, many of these tall buildings and other tall objects have antennas mounted on the top ... there will need to be further work in this area ... Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
On Tue, 15 Jun 2004 07:24:21 -0500 Curtis L. Olson [EMAIL PROTECTED] wrote: Chris Metzler wrote: And while asking about the radio towers . . .my (perhaps wrong) understanding is that they come from some sort of FAA obstruction database; that's why some are at locations where large buildings are located in real life. Is that correct? If so, why not use the FCC's Antenna Structure Registration database (http://wireless.fcc.gov/antenna/) instead? We are actually using the fcc database, however, many of these tall buildings and other tall objects have antennas mounted on the top ... OK, so to make sure I get it, I was incorrect about an FAA obstruction database being used; you do use the FCC ASR database. The correlation with tall buildings is simply because some (most?) tall buildings have antennae on the top. Is this right? If so, are their altitudes simply set to ground level? Are the antenna heights used determined by the height of building + antenna? How reliable are the latlong coordinates in this database? I recently modelled a 40-story building I wanted to put in its real-life location; the latlong I'd dug up for the building didn't match any of the antenna locations, so I didn't know what to substitute for. there will need to be further work in this area ... What work have you already thought of that needs to be done? I'm trying to come up with scenery stuff to contribute these days; but I'm also interested in hearing about problems that need to be solved that don't involve lots of C++ coding (since I dunno how). Presumably some of the work involves figuring out stuff like this: http://www.speakeasy.org/~cmetzler/aerial_aerial.jpg -c -- Chris Metzler [EMAIL PROTECTED] (remove snip-me. to email) As a child I understood how to give; I have forgotten this grace since I have become civilized. - Chief Luther Standing Bear pgpFNpRu3e4lx.pgp Description: PGP signature ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Chris Metzler wrote: OK, so to make sure I get it, I was incorrect about an FAA obstruction database being used; you do use the FCC ASR database. The correlation with tall buildings is simply because some (most?) tall buildings have antennae on the top. Is this right? Yes. If so, are their altitudes simply set to ground level? Are the antenna heights used determined by the height of building + antenna? The FCC database reports ground level, elevation of the top of the tower, and height of the tower. Usually these are self consistant. How reliable are the latlong coordinates in this database? I have no idea. There does appear to be evidence of guessing and human error in the data. I recently modelled a 40-story building I wanted to put in its real-life location; the latlong I'd dug up for the building didn't match any of the antenna locations, so I didn't know what to substitute for. You used to be online mapping services that would (directly or indirectly) get you the lat/lon of things on the image, but I think they realized the usefulness of this and I haven't found anything for free lately ... even mapquest seems to have gotten rid of their aerial photo feature. If you live in the area you could drive over with a gps and survey the building yourself ... drive around the block a couple times and record the track? Gps's don't work well in down town environments because the satellites are often obstructured, but maybe you can get lucky enough to get a decent idea of the location. What work have you already thought of that needs to be done? I'm trying to come up with scenery stuff to contribute these days; but I'm also interested in hearing about problems that need to be solved that don't involve lots of C++ coding (since I dunno how). Presumably some of the work involves figuring out stuff like this: http://www.speakeasy.org/~cmetzler/aerial_aerial.jpg Yes. There are floating towers, there are extremely tall towers in the middle of some runway approaches, there are towers that have multiple antennas mounted to a single structure so you can have double towers on top of each other. It would be nice to calculate a FG ground elevation for each tower so none of them are blatently floating. There is a lot of sanity processing that needs to be done and perhaps some hand checking for blatent cases that interfere with runway approaches. Regards, Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Curtis L. Olson wrote: SNIP You used to be online mapping services that would (directly or indirectly) get you the lat/lon of things on the image, but I think they realized the usefulness of this and I haven't found anything for free lately ... even mapquest seems to have gotten rid of their aerial photo feature. SNIP terragear.microsoft.com and seamless.usgs.gov both give .5 m color ortho photos for many major American cities, and I think 2m bw for the rest of the US. You can get the lat/lon of the corners of the image from both, and both also tell you the scale of the image. terraserver has a nicer interface, but seamless also has access to many other datasets like vector roads and land use. I have a related problem, while we're on the subject. I'm going to place a custom beacon at Andrews. First, it's a military beacon so it has three lights, and second it sits directly on top of a water tower, which will be a separate model. When I submit the taxiway data to Robin with the location of the beacon will this cause your generation scripts to place a standard beacon tower at the same spot? Josh ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Josh Babcock wrote: Curtis L. Olson wrote: SNIP You used to be online mapping services that would (directly or indirectly) get you the lat/lon of things on the image, but I think they realized the usefulness of this and I haven't found anything for free lately ... even mapquest seems to have gotten rid of their aerial photo feature. SNIP terragear.microsoft.com and seamless.usgs.gov both give .5 m color ortho photos for many major American cities, and I think 2m bw for the rest of the US. You can get the lat/lon of the corners of the image from both, and both also tell you the scale of the image. terraserver has a nicer interface, but seamless also has access to many other datasets like vector roads and land use. I have a related problem, while we're on the subject. I'm going to place a custom beacon at Andrews. First, it's a military beacon so it has three lights, and second it sits directly on top of a water tower, which will be a separate model. When I submit the taxiway data to Robin with the location of the beacon will this cause your generation scripts to place a standard beacon tower at the same spot? Josh ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel Sorry, that's terraserver.microsoft.com. Good thing I don't use TerraGen as well, I'd probably just start gibbering. Josh ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
On Tue, 15 Jun 2004 10:41:04 -0500 Curtis L. Olson [EMAIL PROTECTED] wrote: I recently modelled a 40-story building I wanted to put in its real-life location; the latlong I'd dug up for the building didn't match any of the antenna locations, so I didn't know what to substitute for. You used to be online mapping services that would (directly or indirectly) get you the lat/lon of things on the image, but I think they realized the usefulness of this and I haven't found anything for free lately ... even mapquest seems to have gotten rid of their aerial photo feature. Terraserver still has a lat/lon search function; so by repeated tweaking you can get a value if you know a good approximate value to start with. And in principle, you can get that from various places that do address -- lat/lon lookups (MapQuest still has a page that does this). The problem is that they seldom all agree with each other. Last week, I used MapQuest and another similar service to look up my home address; the coordinates the two of them gave me differed by a half a kilometer. I then put each of those coordinates into terraserver's geographic search; I got images back which were about five kilometers from where I live. If you live in the area you could drive over with a gps and survey the building yourself ... drive around the block a couple times and record the track? Gps's don't work well in down town environments because the satellites are often obstructured, but maybe you can get lucky enough to get a decent idea of the location. Yeah, it's my ex-home-town, so not so easy to check it out. But I am planning on using a gps for D.C.-area landmarks shortly. Yes. There are floating towers, there are extremely tall towers in the middle of some runway approaches, there are towers that have multiple antennas mounted to a single structure so you can have double towers on top of each other. It would be nice to calculate a FG ground elevation for each tower so none of them are blatently floating. There is a lot of sanity processing that needs to be done and perhaps some hand checking for blatent cases that interfere with runway approaches. Hmmm. For comparing against ground level altitude, I'd naively think one would need to look at the binary data for the terrain. But for checking for towers on top of each other, and for towers right along runway approaches, I'd think that wouldn't be too hard to check. I'm sure I could in a shell script + add-ons, or maybe python. It would take some cleverness to keep it from taking forever to do, though. I presume that you just have some script that generates entries for the towers in relevant .stg files? Do you do anything to the FCC ASR .dat files (CO.dat, RE.dat, etc.) or do you parse them directly? -c P.S. Side question: what would your opinion be as to the best way to handle the National Mall, or NYC's Central Park, or any other large green space in the middle of some other environment? It seems like a bad idea to create a 6000m x 800m plane in Blender and place that as the Mall, for a number of reasons. Can TerraGear be told to override usage data and put grass within a region bounded by 3 or 4 locations? (I guess this question may be better asked over in terragear-devel) -- Chris Metzler [EMAIL PROTECTED] (remove snip-me. to email) As a child I understood how to give; I have forgotten this grace since I have become civilized. - Chief Luther Standing Bear pgpIz32YO7npg.pgp Description: PGP signature ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Josh Babcock wrote: terragear.microsoft.com and seamless.usgs.gov both give .5 m color ortho photos for many major American cities, and I think 2m bw for the rest of the US. You can get the lat/lon of the corners of the image from both, and both also tell you the scale of the image. terraserver has a nicer interface, but seamless also has access to many other datasets like vector roads and land use. I have a related problem, while we're on the subject. I'm going to place a custom beacon at Andrews. First, it's a military beacon so it has three lights, and second it sits directly on top of a water tower, which will be a separate model. When I submit the taxiway data to Robin with the location of the beacon will this cause your generation scripts to place a standard beacon tower at the same spot? The airport generation scripts create a beacon if there is one in the datafile for that airport, yes. Perhaps we need a way to provide a manually maintained exceptions list when building airports (and scenery). Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Curtis L. Olson wrote: The airport generation scripts create a beacon if there is one in the datafile for that airport, yes. Perhaps we need a way to provide a manually maintained exceptions list when building airports (and scenery). Didn't Robin's data originally contain a field specifying whether the default airport buildings (and presumably, the beacon) should be included? Just as a point of amusement, I'll mention that beacons are sometimes a bit of a joke: they're often U/S, and even when they do work they're extremely difficult to see anywhere near civilization. I'm having trouble remembering if I've ever managed to use a beacon to find an airport at night (the usual tricks, barring a GPS, are to line up on an approach for a bigger airport, or simply to key up the ARCAL and watch where the runway pop up for a smaller airport). Now that I think about it, I might have seen the beacon for Smith's Falls (CYSH) once before I spotted the airport -- or does Smith's Falls have a beacon? All the best, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] radio towers (in the default scenery, and in general)
Curtis L. Olson wrote: Josh Babcock wrote: terragear.microsoft.com and seamless.usgs.gov both give .5 m color ortho photos for many major American cities, and I think 2m bw for the rest of the US. You can get the lat/lon of the corners of the image from both, and both also tell you the scale of the image. terraserver has a nicer interface, but seamless also has access to many other datasets like vector roads and land use. I have a related problem, while we're on the subject. I'm going to place a custom beacon at Andrews. First, it's a military beacon so it has three lights, and second it sits directly on top of a water tower, which will be a separate model. When I submit the taxiway data to Robin with the location of the beacon will this cause your generation scripts to place a standard beacon tower at the same spot? The airport generation scripts create a beacon if there is one in the datafile for that airport, yes. Perhaps we need a way to provide a manually maintained exceptions list when building airports (and scenery). Curt. Maybe if there is a user defined object whose name matches *beacon* within a certain radius of the airport center then automatic generation of a beacon could be suppressed. The radius could be based on the length of the longest runway, or possibly there is some FAA rule about how close airport beacons can be to each other and still be considered different airports. Anyway, the data should already be in whatever database you use to store custom scenery, it just takes some smart scripting to see it. Josh ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
