CCS/BOOSTXL-AOA: I have some questions about the angle measure.

Part Number: BOOSTXL-AOA

Tool/software: Code Composer Studio

When I learn the AoA SDK, I have some questions.

1. I know the angle is between the incident wave and antenna array, but sometimes I get negative Numbers. What does that mean？
2. How do I know which antenna the Angle is coming from？(A1.1, A1.2, A1.3?) Can I output them through python program？
3. Like the Θ in the image above. How do I know if it's a horizontal Angle or a vertical Angle?