TITLE:
Digital Research on the Influence of Longitudinal Zone on the Adjustment of Threshold Crossing Height
AUTHORS:
Chunqing Qu
KEYWORDS:
Forward Slope, Drawback Distance, Threshold Crossing Height
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.15 No.11,
November
5,
2025
ABSTRACT: Antenna rotation is studied for the adjustment of Threshold Crossing Height (TCH) in longitudinal terrain. The TCH value radiated from the M array Gilde Path (GP) beacon can be raised or lowered flexibly. This effect originates from the structure adjustment of the glide slope in the near field (NF) by a rotation of the upper antenna horizontal from reverse rotation ϕ = −10˚ to forward rotation ϕ = +10˚. Except for the situation with a series of backward distances from d = 100 m to 600 m with an interval of 100 m under standard terrain, the uphill from forward slope (FSL) FSL = +2˚ to the downhill FSL = −2˚ with a gap of one degree has been systematically and digitally researched. The bias setting of the GP beacon would be optimized automatically to meet different terrain requirements. The rule of the Threshold Crossing Height and the variety of TCH (ΔT) corresponding to d and FSL have been revealed. The strong correlation between ΔT and FSL can be applied to site selection during the initial stage of runway construction.