Advanced Question Autopilot help, converting inclination to a launch heading

[virii2k]

Is there an easy formula for converting a desired inclination into a launch heading?
I have read http://www.orbiterwiki.org/wiki/Launch_Azimuth
but having a tough time understanding how to calculate
cos(i) = sin(β)cos(φ)

 

[tblaxland]

It is re-arranged for you already on the page to solve for azimuth:

Does that help?

 

[virii2k]

Dosent help much, Im not that great at math but it seems like
it would be TargetHeading = asin(cos(DesiredInclination)/cos(LaunchLatitude))
but its not returning what is should so I am guessing Its wrong

 

[tblaxland]

TargetHeading = asin(cos(DesiredInclination)/cos(LaunchLatitude))

Your formula is correct, so there is an error in the way you are doing the actual calculation. Most likely errors:

1. Incorrect operator precedence - more likely to happen if you are calculating by hand. Your equation above looks OK if that is the actual code you are using.
2. Incorrect units - many maths libraries expect angular units to be in radians instead of degrees. Do your input units match what the functions are expecting?

 

[virii2k]

works alot better when used correctly! I was using degrees for the heading.
Thanks so much!