程序的计算结果如下：
| 计算 1： 天线高度 发射 2m 和 接收 2m = 衰减 153, 8 dB |
计算 2： 天线高度 发射 4m 和 接收 2m = 衰减 150, 8 dB |
无线电传播中的自由空间传播模型，点对点模式：
Terrain Handler: GLOBE
Distance 8,4 km
Frequency 450,0 MHz
Antenna Heights 2, 2 m
Effective Heights 4,1, 3,2 m
Terrain, Delta H 13,0 m
Polarity - Vertical, Eps= 15,00, SGM = ,0050
Continental Temperate, Ns 298,67, K 1,328
Profile: Num Points 800, Dist between Points ,011 km
Single Horizon Path
Diffraction is the Dominant Mode
Coordinates: (61 4 20 N,22 45 40 E) - (61 4 19 N,22 55 3 E)
Estimated Quantiles of Basic Transmission Loss (dB)
Free Space Value 104,0 dB
Relia- Confidence Level
bility 99,0
99,0 153,8 dB |
无线电传播中的自由空间传播模型，点对点模式：
Terrain Handler: GLOBE
Distance 8,4 km
Frequency 450,0 MHz
Antenna Heights 4, 2 m
Effective Heights 4,1, 3,2 m
Terrain, Delta H 13,0 m
Polarity - Vertical, Eps= 15,00, SGM = ,0050
Continental Temperate, Ns 298,67, K 1,328
Profile: Num Points 800, Dist between Points ,011 km
Single Horizon Path
Diffraction is the Dominant Mode
Coordinates: (61 4 20 N,22 45 40 E) - (61 4 19 N,22 55 3 E)
Estimated Quantiles of Basic Transmission Loss (dB)
Free Space Value 104,0 dB
Relia- Confidence Level
bility 99,0
99,0 150,8 dB |
| 计算 3： 天线高度 发射 6m 和 接收 2m = 衰减 147, 8 dB/line of sight |
计算 4： 天线高度 发射 8m 和 接收 2m = 衰减 145, 6 dB/line of sight |
无线电传播中的自由空间传播模型，点对点模式：
Terrain Handler: GLOBE
Distance 8,4 km
Frequency 450,0 MHz
Antenna Heights 6, 2 m
Effective Heights 4,1, 3,2 m
Terrain, Delta H 13,0 m
Polarity - Vertical, Eps= 15,00, SGM = ,0050
Continental Temperate, Ns 298,67, K 1,328
Profile: Num Points 800, Dist between Points ,011 km
Line-Of-Sight Path
Coordinates: (61 4 20 N,22 45 40 E) - (61 4 19 N,22 55 3 E)
Estimated Quantiles of Basic Transmission Loss (dB)
Free Space Value 104,0 dB
Relia- Confidence Level
bility 99,0
99,0 147,8 dB |
无线电传播中的自由空间传播模型，点对点模式：
Terrain Handler: GLOBE
Distance 8,4 km
Frequency 450,0 MHz
Antenna Heights 8, 2 m
Effective Heights 4,1, 3,2 m
Terrain, Delta H 13,0 m
Polarity - Vertical, Eps= 15,00, SGM = ,0050
Continental Temperate, Ns 298,67, K 1,328
Profile: Num Points 800, Dist between Points ,011 km
Line-Of-Sight Path
Coordinates: (61 4 20 N,22 45 40 E) - (61 4 19 N,22 55 3 E)
Estimated Quantiles of Basic Transmission Loss (dB)
Free Space Value 104,0 dB
Relia- Confidence Level
bility 99,0
99,0 145,6 dB |
视线 line of sight 是指超过 50% 以上的菲涅耳区不被阻挡。
总结:
当将天线提高2米到8米，就可以用更少的功率来达到同样的距离。
如果发射天线高度架高6米，那么10瓦的有效发射功率的覆盖范围与66瓦的有效发射功率是一样的! |
