noun
depression angle; angle of dip
Technical term in geometry, surveying, and optics for the angle below the horizontal plane when looking downward.
測量では、俯角を正確に測定することが重要だ。
In surveying, it is important to measure the depression angle accurately.
この望遠鏡の俯角は最大で30度まで調整できる。
The depression angle of this telescope can be adjusted up to 30 degrees.