On Thu, Feb 06, 2003 at 10:22:18PM -0600, Curtis L. Olson wrote:
So, could the Lambert Conformal Conic be the projection I am looking for ?
Any help or pointers are appreciated.
You might be thinking too hard about this.
Yeah, I guess. But then, I'm too often a perfectionist ;-)
Manuel Bessler writes:
$x = $w/2 + ($lon - $center_lon) * $deg_to_nm * $scale * $xfact;
$y = $h/2 - ($lat - $center_lat) * $deg_to_nm * $scale;
($x, $y) is the coordinates (in screen space) where you should draw
the object.
This is known to work pretty well over a local
Norman Vine writes:
This works fine for a 'map' but straight lines will not be great circles
which AFAIK is still the standard for *most* aviation 'charts', both
paper and electronic versions
It depends on scale. World Aeronautical Charts (1:1,000,000) and
VNCs/Sectionals (1:500,000)
I couldn't find any good info on what kind of map projection
technique to use for the ND.
ie. mapping lat/lon to x/y-screen coord.
I took a look at the OpenGC source,
and as far as I understand, it uses a technique which converts
RijksDriehoeks to Hayford.
I tried to google a bit on
Manuel Bessler
I also had the chance to ask a real airliner pilot. He said that on A340
and B744, a line on the NDs represents the shortest path between two
points, ie. a Great Circle route. He also said that on older NDs (A300
or A310, I forgot which he mentioned) the line is not a Great
Manuel Bessler writes:
Did a little more research... (blindly shooting some search requests
at google)
Something that came up was, the Lambert Conformal Conic Projection.
I also had the chance to ask a real airliner pilot. He said that on A340
and B744, a line on the NDs represents the
Curtis L. Olson writes:
You might be thinking too hard about this.
The following seems to work really slick for me (assuming you are
doing smaller area maps or don't care about some distortion as you get
towards the top/bottom of the map. Even if this isn't quite good
enough for your
Norman Vine writes:
This works fine for a 'map' but straight lines will not be great circles
which AFAIK is still the standard for *most* aviation 'charts', both
paper and electronic versions
Fair enough ... I guess it all depends on the needs of the end
application. It's about as simple
Hi Norman,
I heard about this... this still doesn't help me with the specific
projection technique used on NDs.
the proj package can do the conversion for you
I understand that, but my what I would like to know is: Is the
RijksDriehoeks conversion to Hayford as used by OpenGC the method
Manuel Bessler writes:
I am working on something similar to OpenGC, but not
OpenGL based, but rather xlib-based... (its supposed to run on lowlevel
Pentiums w/ non-3D accel graphics cards, maybe even 486s)
I couldn't find any good info on what kind of map projection
technique to use for
On Sat, Feb 01, 2003 at 06:04:21PM -0500, Norman Vine wrote:
Manuel Bessler writes:
I am working on something similar to OpenGC, but not
OpenGL based, but rather xlib-based... (its supposed to run on lowlevel
Pentiums w/ non-3D accel graphics cards, maybe even 486s)
I couldn't find
Manuel Bessler writes:
On Sat, Feb 01, 2003 at 06:04:21PM -0500, Norman Vine wrote:
Manuel Bessler writes:
I couldn't find any good info on what kind of map projection
technique to use for the ND.
ie. mapping lat/lon to x/y-screen coord.
I took a look at the OpenGC source,
and
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