Analysis of X-Band Link Performance Degradation Caused by Adjacent Satellite
As more satellites are designed to downlink their observed image data through the X-band frequency band, it is inevitable that the occupied bandwidth of a target satellite will overlap with that of other X-band downlink satellites. For sun-synchronized low earth orbit satellites, in particular, it...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Korean Space Science Society (KSSS)
2011-12-01
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Series: | Journal of Astronomy and Space Sciences |
Subjects: | |
Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2011/v28n4/OJOOBS_2011_v28n4_299.pdf |
Summary: | As more satellites are designed to downlink their observed image data through the X-band frequency band, it is inevitable
that the occupied bandwidth of a target satellite will overlap with that of other X-band downlink satellites. For sun-synchronized
low earth orbit satellites, in particular, it can be expected that two or more satellites be placed within the looking
angle of a ground station antenna at the same time. Due to the overlapping in the frequency band, signals transmitted
from the adjacent satellites act as interferers, leading to degraded link performance between target satellite and ground
station. In this paper, link analysis was initiated by modeling the radiation pattern of ground station antenna through a
validated Jet Propulsion Laboratory peak envelope model. From the relative antenna gain depending on the offset angle
from center axis of maximum antenna directivity, the ratio of received interference signal level to the target signal level
was calculated. As a result, it was found that the degradation increased when the offset angle was within the first null
point of radiation pattern. For a 7.3 m antenna, serious link degradation began at an offset angle of 0.4 degrees. From this
analysis, the link performance of the coming satellite passes can be recognized, which is helpful to establish an operating
procedure that will prevent the ground station from receiving corrupted image data in the event of a degraded link. |
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ISSN: | 2093-5587 2093-1409 |