RE: [geonet]: Find the heading going down a line

[Harris, Rob (Sudbury)]

I don't know if there's a function for doing this, but offhand I can think of a quick and dirty method:   Create a new channel and call it NULL.  Fill it with zeros. Using Utilities -> Make Distance Channel, make a distance channel based on your X and NULL channels.  Call it X_DISTANCE. Repeat this for Y and NULL to create a Y_DISTANCE channel. Make a new channel called HEADING and fill it with the formula HEADING = 90 - ATAN(Y_DISTANCE / X_DISTANCE).   I'm pretty sure this should work.   Cheers,   Rob Harris   -----Original Message----- From: skyhunter [mailto:[EMAIL PROTECTED]] Sent: August 20, 2002 10:51 AM To: GEONET Subject: [geonet]: Find the heading going down a line Hi all,   Does anyone know of a way to obtain the heading between fiducials for a flight line. For instance, I have a flight path that turns on line and I want to see if I can detect when the plane actually begins the line by calculating the heading between time 1 and time 2, time 2 and time 3, etc and detecting when the line begins as when the heading equal 180 degrees.     Aaron Balasch Sky Hunter Technologies Inc. Suite 101, 1725 10th Avenue S.W. Calgary, Alberta T3C 0K1 email: [EMAIL PROTECTED] phone: 403-228-2175 fax: 403-244-7955