بررسي اثر زمين در شكل دهي پرتو سيستم ناوبري تنظيم ارتفاع Glide Path

Investigation of Ground Effect on the Beamforming of the Glide Path Altitude Adjustment Navigation System

ﺳﯿﺴﺘﻢ ﺗﻨﻈﯿﻢ ارﺗﻔﺎع Glide Path ﯾﮑﯽ از اﺑﺰارﻫﺎي ﺳﯿﺴﺘﻢ ﻧﺎوﺑﺮي ﻓﺮود ILS اﺳﺖ ﮐﻪ وﻇﯿﻔﮥ آن در ﻫﻨﮕﺎم ﻓﺮود ﻫﻮاﭘﯿﻤﺎ ﮐﻤﮏ ﺑﻪ ﯾﺎﻓﺘﻦ زاوﯾﮥ ارﺗﻔﺎع ﻫﻮاﭘﭙﻤﺎ ﻧﺴﺒﺖ ﺑﻪ ﺑﺎﻧﺪ ﻓﺮود از ﻃﺮﯾﻖ ارﺳﺎل ﺳﯿﮕﻨﺎلﻫﺎي رادﯾﻮﯾﯽ اﺳﺖ. اﯾﻦ ﮐﺎر از ﻃﺮﯾﻖ ارﺳﺎل دو ﺳﯿﮕﻨﺎل ﺑﺎ اﻟﮕﻮي ﺧﺎﺻﯽ اﻧﺠﺎم ﻣﯽﮔﯿﺮد ﮐﻪ ﻧﺴﺒﺖ اﯾﻦ دو ﺳﯿﮕﻨﺎل در ﯾﺎﻓﺘﻦ زاوﯾﻪ ارﺗﻔﺎع ﺑﻪ ﮐﺎر ﻣﯽ آﯾﺪ. رﻓﺘﺎرﻣﻮج اﻟﮑﺘﺮوﻣﻐﻨﺎﻃﯿﺴﯽ ﻓﺮﺳﺘﺎدهﺷﺪه از ﺳﯿﺴﺘﻢ و اﻧﻌﮑﺎس آن از زﻣﯿﻦ ﺑﺎﻋﺚ ﺑﺮ ﻫﻢﺧﻮردن اﻟﮕﻮي ﺗﺸﻌﺸﻌﯽ ارﺳﺎﻟﯽ ﻣﯽﺷﻮد. ﻣﺪﻟﺴﺎزي اﯾﻦ اﺛﺮ ﮐﻪ ﺗﺤﺖ ﻋﻨﻮان اﺛﺮ زﻣﯿﻦ ﺷﻨﺎﺧﺘﻪ ﻣﯽﺷﻮد در وزندﻫﯽ و ﺷﯿﻔﺖ ﻓﺎز ﻣﻨﺎﺳﺐ ﺳﯿﮕﻨﺎلﻫﺎي آﻧﺘﻦﻫﺎي ارﺳﺎل ﺑﺴﯿﺎر اﻫﻤﯿﺖ دارد. در اﯾﻦ ﻣﻘﺎﻟﻪ ﺷﮑﻞدﻫﯽ اﻟﮕﻮي ﺗﺸﻌﺸﻌﯽ ارﺳﺎﻟﯽ ﺳﯿﺴﺘﻢ G/P ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ اﻧﻌﮑﺎس زﻣﯿﻦ ﻣﺪلﺳﺎزي دﻗﯿﻖ ﺷﺪه اﺳﺖ و ﭼﻨﺪ ﺷﮑﻞ ﭘﺮﺗﻮ ﺳﯿﺴﺘﻢ واﻗﻌﯽ ﻧﯿﺰ ﺷﺒﯿﻪ ﺳﺎزي ﺷﺪه اﺳﺖ.

The Glide Path altitude adjustment system is one of the tools of the landing navigation system (ILS) that helps the airplane to find its angle related to the runway by sending radio signals. It is done by sending two signals with a predetermined radiation pattern. The ratio of these two signals is used to find the elevation angle. The behavior of the electromagnetic wave sent from the system and its reflection from the ground causes the transmitted pattern to be distorted. This effect, known as the ground effect, is very important in transmitting antenna signals' accurate weight and phase shift. In this paper, the pattern of the transmitted pattern of the G/P system is modeled by considering the ground reflection, and several real systems are simulated