Sign in to follow this  
wsieffert

Navigational signal strenght

Recommended Posts

HiI have started to incorporate (A:ADF1 signal,number) and similar into my avionics gauges in an attempt to simulate real(er) world reception, but I'm not confident enough on how the real things actually work and respond to this.I've noticed that the normal avionics builtin is "triggered" with a signal strenght of 256, and it grows exponentially the closer you get to the station. The needles will contain no errors whatsoever.Now to the questions.Should I use an on/off system for this signal, where the needle should be pointing to the station or resting at 3 o'clock, or should I inflict errors to the needle instead to illustrate signal "quality"?How does this signal "quality" affect the different systems; NDB, VOR, LLZ, and DME stations?Is the classification of default navaids within FS2002 correct?

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

I find the NAVAIDs in FS2002 to be correct. The usual problem is with real pilots that fly using the same NAVAIDs in real life. Real life environment causes differences in range, stability, blocking of frequencies. It is not possible to incorporate these infinite number of environmental peculiarities into the flight simulator.

Share this post


Link to post
Share on other sites

Well, I was hoping to check for (L:Signal Strenght) which is my own instead of (A:Signal Strenght) which is the builtin. My version is based on the builtin, but at the outer boundaries of the signal, I will add some randomness to it.But I'm not sure how the needles should react. Should they have errors in where they are pointing, or should I block out any signal less than so so?Side question: Can I get information about ground height at a certain location from aircraft position? I mean, to check if there are mountains in the way, blocking a VOR signal?

Share this post


Link to post
Share on other sites

I think the problem will be that you have no way of measuring the height of distance objects in the scenery for objects not directly below your aircraft. Even real aircraft, without special equipment, can't determine the height of distance objects, e.i., RADALT.I guess you could figure out some algorithm using LAT/LON to determine that the Rocky Mountains were in the way, your aircraft height, the straight line method to the NAVAID, and probably a whole bunch more variables just for this one NAVAID.Good Luck!:-eek

Share this post


Link to post
Share on other sites

Yes, I know this would become a problem. The way I tried to solve this was just assuming that whenever you're closer to the ground, the less stable the signal becomes, especially when the signal is already pretty weak in strenght. This is possible.But then I checked out the variables more, and found a pretty interresting one; latlonalt for the various signals. But I could never get any type of information about this. If I could use this, I could get the difference between aircraft height and station height, compare this to radio height, and do whatever I felt useful to crap out the signal.But anyway; should I turn reception on and off at intervals, or should I introduce a needle error? The aircraft I'm being passenger in in real life is pure VFR, i.e. doesn't have ANY navigation systems, so it's hard to check :)

Share this post


Link to post
Share on other sites

I have not ever heard of needle error in this case. I think the NAVAID equipment can't resolve or has a unstable signal, it just shuts off the output until it receives a reliable signal.I would search the web for information on how the VOR, VORTAC, TACAN NAVAID equipment resolve this area. I don't have ready reference to this information since I retired.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this