Dene, On Wed, Feb 14, 2007 at 09:02:54PM +1300, Dene wrote: [...] > I've had a chance to review the path loss formulae > > Very simply, the height factors of the TX and Rx aerials is only used to > translate what might be an oblique angle into a horizontal distance, in > all reality when ATC becomes important the path distance between point > to point and terrestial distance can be ignored. > The frequency factor can be formed into a constant mid-band freq of say > 118Mhz > As has been stated, the rain attenuation etc can be ignored as being > insignificant at VHF > Assume standard TX power of 25W ( I stand corrected 25W= 14dBW or 34dBm > ...not 17/37) > Assume standard RX sensitivity of -114dBm for 12dB SINAD (roughly > translated signal to noise) > Assume all cable losses are balanced by aerial gains (eg no extra losses > or gains) > > with all these assumptions a distance of > 461km pops out of the formulae. > > what is perhaps more significant and can't be assumed or ignored is > co-channel interference (previously referred to as "clutter" I think) > > as a starting point I would use 461 km and concentrate on simulating > clutter or doubling and maybe making distant signals more noisy ( double > the noise for each extra 100 km) [...]
Ok, thanks! That's quite a wider range as i thaught. Regards, Holger -- ##### #### ## ## Holger Wirtz Phone : (+49 30) 884299-40 ## ## ## ### ## DFN-Verein Fax : (+49 30) 884299-70 ## ## #### ###### Stresemannstr. 78 E-Mail: [EMAIL PROTECTED] ## ## ## ## ### 10963 Berlin ##### ## ## ## GERMANY WWW : http://www.dfn.de GPG-Fingerprint: ABFA 1F51 DD8D 503C 85DC 0C51 E961 79E2 6685 9BCF ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
