DWM3000EVK Antenna Delay Calibration

I am implementing a positioning system using dwm3000evks with ds twr at the moment. I have basically completed a first prototype now, but i noticed that the distance measurements are partially very inaccurate. Is there more documentation or even a code template available for the antenna calibration? I found the part about antenna delay in the dwm3000 manual, but I was hoping for something more into detail.

Thank you already in advance for your help!

there is an app note that covers antenna delay calibration.