mytec
defa3ad440
Major refactoring of RFCP backend: - Modular propagation models (8 models) - SharedMemoryManager for terrain data - ProcessPoolExecutor parallel processing - WebSocket progress streaming - Building filtering pipeline (351k → 15k) - 82 unit tests Performance: Standard preset 38s → 5s (7.6x speedup) Known issue: Detailed preset timeout (fix in 3.1.0)
41 lines
849 B
Python
41 lines
849 B
Python
"""
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Knife-edge diffraction geometry calculations.
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"""
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import math
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def knife_edge_loss(
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d1_m: float,
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d2_m: float,
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h_m: float,
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wavelength_m: float,
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) -> float:
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"""
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Calculate diffraction loss over single knife edge.
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Args:
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d1_m: Distance TX to obstacle
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d2_m: Distance obstacle to RX
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h_m: Obstacle height above LOS (positive = above)
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wavelength_m: Signal wavelength
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Returns:
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Loss in dB (>= 0)
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"""
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if d1_m <= 0 or d2_m <= 0 or wavelength_m <= 0:
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return 0.0
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v = h_m * math.sqrt(2 * (d1_m + d2_m) / (wavelength_m * d1_m * d2_m))
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if v < -0.78:
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L = 0.0
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elif v < 0:
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L = 6.02 + 9.11 * v - 1.27 * v ** 2
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elif v < 2.4:
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L = 6.02 + 9.11 * v + 1.65 * v ** 2
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else:
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L = 12.95 + 20 * math.log10(v)
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return max(0.0, L)
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