mapping - Geometry of a radial coordinate to Cartesian with bounding points -
i need find 4 points in latitude/longitude format surrounding given center point , resulting algorithm (if possible).
known information: equal distances each "bin" center of point (radar) outward. example = .54 nautical miles.
1 degree beam width. center point of "bin"
this image in polar coordinates (i think similar radial coordinates???):
i need convert polar/radial cartesian , should able formula.
x = r × cos( θ ) y = r × sin( θ )
so need find "bin" outline coordinates (4 corners) can draw polygon in cartesian coordinate space.
i'm using delphi/pascal coding, might able convert other languages if have sample algorithm.
thanks suggestions or sample algorithms. regards, bryan
you need convert same coordinate system , impose distance criteria follows:
- convert center point geographic coordinates polar coordinates yield (rc, θc)
- convert center point polar cartesian coordinates using equations yielding (xc, yc)
the corner points on right side of center points (xr, yr) satisfy equation
(xr - xc)2 + (yr - yc)2 = d2
[rrcos(θc+0.5o) - xc]2 + [rrsin(θc+0.5o) - yc]2 = d2
where d=distance between center point , corner points
everything known in above equation except rr. should yield quadratic equation 2 solutions can solve. 2 corner points on right side.
- repeat step 3 angle θc-0.5o corner points on left side.

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