Re: [Flightgear-devel] fgmap navaids
Ron Jensen Hi Vivian I'm more than willing to be corrected on this one, but my understanding is as follows: A VORTAC station has 3 frequencies in RL - TACAN, VOR, and DME. This is my understanding, too. Further A TACAN channel includes 3 frequencies, Two for TACAN/DME and one for VOR/ILS. [1] I'd like to see where this idea comes from - not [1], which is a very simplistic description. A TACAN channel includes just 2 frequencies - airborne (or interrogation) and ground (or reply). If you have a TACAN receiver (military), the response frequency contains both the bearing and range information. If you have a DME instrument (civilian) you will get range information only. VOR is described by its frequency. Thus a VOR/DME station should have a frequency and a channel associated with it and a DME just a channel. AKAIKS DAFIF does just this. If Navaids are collocated as defined by AFMAN33-120_USAFESUP1_I 17 DECEMBER 2004, then frequency pairing is mandated. However, not all TACAN channels have an associated VOR frequency assigned. Nav.dat seems to assume that TACAN _uses_ the associated VOR assigned frequency. Where there is no VOR frequency / TACAN channel pairing, then nav.dat, in a fit of madness, seems to use the mandated Localizer / TACAN channel pairing. What it does for TACAN channels which have neither, I can't find out for now. Perhaps there are none. We have a GIGO situation here. In FG nav.dat only the VOR and DME are held. Actually, nav.dat only holds the VOR freq. The DME uses the associated VOR frequency. Yes - incorrectly - should be the frequency indicated by the DME Channel Thus it is a fix in the case of VORTAC to misalign the TACAN channel/frequency pairing to the VOR frequency in stead of the TACAN frequency. There is not a mis-alignment. The TACAN spec includes the VOR freq pairing, as well as the DME freq pairing. Not for all TACAN channels, at least not in the reference which I am using (AFMAN33-120_USAFESUP1_I 17 DECEMBER 2004). It is simply incorrect to use the paired VOR frequency for a stand alone TACAN ... It is possible in real life to tune a VOR/DME reciever to (most?) TACAN stations and receive DME information. Unfortunately, there are other stations in the world which are TACAN only, which seem to have the correct TACAN frequency assigned: Flesland TACAN is one such example. Flesland TACAN (FLE) uses channel 092X [2] Flesland VOR/DME (FLS) uses channel 102Y (115.55 MHz) [3] zgrep Flesland nav.dat.gz: 12 60.300036 005.213589185 11450 130 0.000 FLE Flesland TACAN 12 60.311261 005.212194213 11555 130 0.000 FLS Flesland VOR-DME I'm wrong here - the nav.dat data is incorrect, well rubbish really. The only correct bit is that the TACAN and VOR-DME are separate. (Well, and the positions) Under the current version of TACAN.dat FLE is tuned using 058Y and FLS is not tuneable. FLS should give DME only to the onboard TACAN system, currently the TACAN system in FG would ignore it, if it were tuneable, I think. Thus we fix the VORTAC at the expense of the TACAN. I don't see this. With a corrected TACAN.dat and the current nav.dat both VORTAC and TACAN work fairly well. I use HIF TACAN all the time: 12 41.120503 -111.963681 4806 11120 40 0.000 HIF Hill TACAN The correct fix is to modify nav.dat to show all 3 frequencies for the VORTAC stations. If I understand correctly, you are concerned because the current TACAN uses the name of the DME station to determine whether or not to provide TACAN service. Adding a section for TACAN Azimuth that mirrors the DME entries for VORTAC and TACAN stations makes sense, the TACAN DME would respond to all DME entries (12/13) in nav.dat and TACAN azimuth would respond only to the new (number??) TACAN entries in nav.dat. Overall, I don't see a way to proceed without first replacing TACAN.dat. I would very much like get nav.dat fixed so that it corresponds to the RL situation, and we can provide proper VOR, TACAN and DME facilities. I'm not clear how practical this is: probably cannot be done, in the short term at least. (If you feel inclined to take that on, I for one would be delighted.) It would also probably require a rewrite of some of the DME code. In the interests of expediency, I think the short term (and probably long term as well) is to use the TACAN channel / VOR frequency pairing which you produced, and just accept that there are blocks of channels which cannot be used, and hope that nav.dat copes with that situation. We at FG pride ourselves on our accuracy and realism. This is all far from that. I really, really, don't like to do this. As I said before, it's a hack to fix a hack, and I'm sure will lead to misunderstandings in the future. Overall, this has forced me to research this properly, instead of relying on memory. I hope that we are all clear on this now. I suppose we ought to record all this somewhere.
Re: [Flightgear-devel] fgmap navaids
Ron Jensen -Original Message- From: [EMAIL PROTECTED] [mailto:flightgear- [EMAIL PROTECTED] On Behalf Of Sent: 02 June 2006 04:29 To: FlightGear developers discussions Subject: Re: [Flightgear-devel] fgmap navaids On Fri, 2006-06-02 at 11:04 +1000, Pigeon wrote: The only thing that I'm missing now is TACAN. It would be really great (and a slight improvement on Atlas) if the TACAN channel for a suitably equipped airfield was shown. I have just noticed I have sorta misinterpreted some of the nav data regarding TACAN, i.e. at the moment all the TACAN are missing on the map. I will look into this soon. And perhaps I shall ask you or Vivian on IRC later on about any specifics I needed to know. Can we get TACAN channel assignments fixed while you're at it? Currently the TACAN system assigns random, bogus channels that don't jive with the real world nav data. I had a simple fix but Vivian thought it was a 'hack'. I'm more than willing to be corrected on this one, but my understanding is as follows: A VORTAC station has 3 frequencies in RL - TACAN, VOR, and DME. In FG nav.dat only the VOR and DME are held. Thus it is a fix in the case of VORTAC to misalign the TACAN channel/frequency pairing to the VOR frequency in stead of the TACAN frequency. Unfortunately, there are other stations in the world which are TACAN only, which seem to have the correct TACAN frequency assigned: Flesland TACAN is one such example. Thus we fix the VORTAC at the expense of the TACAN. The correct fix is to modify nav.dat to show all 3 frequencies for the VORTAC stations. As I say, I think this is the case ... Vivian ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
On Fri, 2006-06-02 at 14:17 +0100, Vivian Meazza wrote: Hi Vivian I'm more than willing to be corrected on this one, but my understanding is as follows: A VORTAC station has 3 frequencies in RL - TACAN, VOR, and DME. This is my understanding, too. Further A TACAN channel includes 3 frequencies, Two for TACAN/DME and one for VOR/ILS. [1] In FG nav.dat only the VOR and DME are held. Actually, nav.dat only holds the VOR freq. The DME uses the associated VOR frequency. Thus it is a fix in the case of VORTAC to misalign the TACAN channel/frequency pairing to the VOR frequency in stead of the TACAN frequency. There is not a mis-alignment. The TACAN spec includes the VOR freq pairing, as well as the DME freq pairing. It is possible in real life to tune a VOR/DME reciever to (most?) TACAN stations and receive DME information. Unfortunately, there are other stations in the world which are TACAN only, which seem to have the correct TACAN frequency assigned: Flesland TACAN is one such example. Flesland TACAN (FLE) uses channel 092X [2] Flesland VOR/DME (FLS) uses channel 102Y (115.55 MHz) [3] zgrep Flesland nav.dat.gz: 12 60.300036 005.213589185 11450 130 0.000 FLE Flesland TACAN 12 60.311261 005.212194213 11555 130 0.000 FLS Flesland VOR-DME Under the current version of TACAN.dat FLE is tuned using 058Y and FLS is not tuneable. FLS should give DME only to the onboard TACAN system, currently the TACAN system in FG would ignore it, if it were tuneable, I think. Thus we fix the VORTAC at the expense of the TACAN. I don't see this. With a corrected TACAN.dat and the current nav.dat both VORTAC and TACAN work fairly well. I use HIF TACAN all the time: 12 41.120503 -111.963681 4806 11120 40 0.000 HIF Hill TACAN The correct fix is to modify nav.dat to show all 3 frequencies for the VORTAC stations. If I understand correctly, you are concerned because the current TACAN uses the name of the DME station to determine whether or not to provide TACAN service. Adding a section for TACAN Azimuth that mirrors the DME entries for VORTAC and TACAN stations makes sense, the TACAN DME would respond to all DME entries (12/13) in nav.dat and TACAN azimuth would respond only to the new (number??) TACAN entries in nav.dat. Overall, I don't see a way to proceed without first replacing TACAN.dat. [1] http://www.vectorsite.net/ttradar5.html#m3 [2] http://worldaerodata.com/wad.cgi?nav=FLESLANDnav_id=FLEnav_type=3 [3] http://worldaerodata.com/wad.cgi?nav=FLESLANDnav_id=FLSnav_type=4 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
On Thursday 01 June 2006 01:29, Pigeon wrote: I have just put up the navaids stuff to the fgmap for people to test/play with a bit. It is at http://mpmap02.flightgear.org/ or http://pigeond.net/flightgear/fg_server_map.html and there is now a new nav tab in the menu. Please let me know any feedbacks and bugs. Great work Pigeon, as ever! The only thing that I'm missing now is TACAN. It would be really great (and a slight improvement on Atlas) if the TACAN channel for a suitably equipped airfield was shown. But that's nitpicking, what you've done so far is fantastic... Cheers, AJ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
The only thing that I'm missing now is TACAN. It would be really great (and a slight improvement on Atlas) if the TACAN channel for a suitably equipped airfield was shown. I have just noticed I have sorta misinterpreted some of the nav data regarding TACAN, i.e. at the moment all the TACAN are missing on the map. I will look into this soon. And perhaps I shall ask you or Vivian on IRC later on about any specifics I needed to know. Pigeon. ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
On Fri, 2006-06-02 at 11:04 +1000, Pigeon wrote: The only thing that I'm missing now is TACAN. It would be really great (and a slight improvement on Atlas) if the TACAN channel for a suitably equipped airfield was shown. I have just noticed I have sorta misinterpreted some of the nav data regarding TACAN, i.e. at the moment all the TACAN are missing on the map. I will look into this soon. And perhaps I shall ask you or Vivian on IRC later on about any specifics I needed to know. Can we get TACAN channel assignments fixed while you're at it? Currently the TACAN system assigns random, bogus channels that don't jive with the real world nav data. I had a simple fix but Vivian thought it was a 'hack'. Thanks, Ron ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] fgmap navaids
Hi all, I have just put up the navaids stuff to the fgmap for people to test/play with a bit. It is at http://mpmap02.flightgear.org/ or http://pigeond.net/flightgear/fg_server_map.html and there is now a new nav tab in the menu. Hope the interface is straight forward. Currently there are mainly two ways of using it: - Search a navaid by its id/code or name. After a search, results would be shown at the bottom, and you can show and pan to a navaid by clicking on it in the result list. - Show all navaids in the current view of the map. You can select what type of navaid to search for/show as well. You can toggle a type of navaid to be visible/invisible. There are certain things on my TODO list: - Drawing proper glideslope/etc for ILS, currently it only shows the name and the freq for the ILS. - Heliport is not done/shown yet. - Optimizing the database/queries. I haven't tune anything yet. I guess this is one of the purposes of this testing release. So please don't mind if sometimes the lookups are slow. - Adding metar reports for airports Please let me know any feedbacks and bugs. http://mpmap01.flightgear.org/ stays as it is, just in case the new fgmap is really broken :) Pigeon. ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
There are certain things on my TODO list: Also, airways are not done yet. Pigeon. ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] fgmap navaids
WOW!! great stuff Pigeon... tried to out-wit it by putting in Titahi Bay (a local NDB) straight back at me!!! looking forward to airways Cheers :-D ene From: Pigeon [EMAIL PROTECTED] Reply-To: FlightGear developers discussions flightgear-devel@lists.sourceforge.net To: flightgear-devel@lists.sourceforge.net Subject: [Flightgear-devel] fgmap navaids Date: Thu, 1 Jun 2006 10:29:35 +1000 Hi all, I have just put up the navaids stuff to the fgmap for people to test/play with a bit. It is at http://mpmap02.flightgear.org/ or http://pigeond.net/flightgear/fg_server_map.html and there is now a new nav tab in the menu. Hope the interface is straight forward. Currently there are mainly two ways of using it: - Search a navaid by its id/code or name. After a search, results would be shown at the bottom, and you can show and pan to a navaid by clicking on it in the result list. - Show all navaids in the current view of the map. You can select what type of navaid to search for/show as well. You can toggle a type of navaid to be visible/invisible. There are certain things on my TODO list: - Drawing proper glideslope/etc for ILS, currently it only shows the name and the freq for the ILS. - Heliport is not done/shown yet. - Optimizing the database/queries. I haven't tune anything yet. I guess this is one of the purposes of this testing release. So please don't mind if sometimes the lookups are slow. - Adding metar reports for airports Please let me know any feedbacks and bugs. http://mpmap01.flightgear.org/ stays as it is, just in case the new fgmap is really broken :) Pigeon. ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel _ Need more speed? Get Xtra Broadband @ http://jetstream.xtra.co.nz/chm/0,,202853-1000,00.html ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
