Heading Values

I have a project using a drone to capture a roof of a property. The shots are in plan, 45 degs and elevation. I need to work out what direction the cameras are facing from the exported data from CR. I have a csv file ( link below) showing the x,y,alt,heading,pitch,roll,f,u,v,k1.k2 and k3 values. However the heading values do not seem to make sense. Can anyone give me some indication as to what they are recording? The values range from -180 to 180 but do not have any values between -45 and 45. If these are not the correct values to use then does anyone know where I can find them or calculate them?

bhouse.csv

Many thanks