VIflyer From US Virgin Islands, joined May 1999, 502 posts, RR: 0 Posted (16 years 4 months 1 week 6 days 21 hours ago) and read 1489 times:
I know on all modern commercial aircraft contains a modern weather radar. I just was courious if this radar could be used to gain navagational fixes? I know and seen articles how the radar on the B757/767 could be used in a crude ground mapping mode (basically placing the radar antannas elevation as far down as possible and selecting the fastest scan rate). Basically can this be also done on other aircraft or has this option been eliminated by radar manufactuers?
SpUd From United Kingdom, joined Apr 2011, 0 posts, RR: 0
Reply 2, posted (16 years 4 months 1 week 5 days 22 hours ago) and read 1489 times:
Dash8 is right. By virtue of what it is, you cant stop it from getting a ground return. You can 'tweak' things to reduce ground returns and clutter 'wx' or increase it 'map' mode. Its just playing with array angles (tilt) and the gain (sensitivity). Also software filters can enhance or exclude different returns.
VIflyer From US Virgin Islands, joined May 1999, 502 posts, RR: 0
Reply 3, posted (16 years 4 months 1 week 5 days 21 hours ago) and read 1489 times:
I think I phrases my question wrong. What I mean is that in the Millitary (before GPS or even reliable guidance systems) they used radar to look for a specific object on the ground and use that to make navigational fixes. I readed even the modern McDD F-15E Strike Eagle has the ablity to use it's radar to gain navigatioal fixes. What I ment to say was, can modern airlines (even though not needed in todays modern airways) used there weather radar to update and gain navigational fixes ?
Dash8 From New Zealand, joined Aug 2005, 14 posts, RR: 0
Reply 4, posted (16 years 4 months 1 week 5 days 18 hours ago) and read 1489 times:
No they can't. Modern military fighters like the strike eagle have very sophisticated radars with filters designed especially for their role. These radars also aren't weather radars since it wouldn't be able to see any weather due to its filters. These radars only pick up objects that pertrude the ground level past a certain threshold. Anything below this and the radar's filters recognise it as part of the ground and eliminate it.
That is why an F-15 can base waypoints on anything from ships at sea to an antenae alongside a road.
However nowadays these radars are coupled to the navigational system to point exactly on the coordinates programmed into it. So if you would have a target coordinate set in the waypoint system upon activating that waypoint, the radar would point directly at this coordinate, thus eliminating the need for searching.
Commercial radars are for weather and therefor would have no filters. The only landmarks you would be able to recognise on these are rivers, mountain ranges and things of this nature.