Citation
Abstract
This article presents a case study of potential interference from a 2-GHz transmitter in the Deep Space Network (DSN) station in Robledo, Spain, to the International Mobile Telecommunications (IMT)-2000 mobile receivers in the city of Madrid about 50 km away. This study has included the effect of terrain between Robledo and Madrid in evaluating the propagation modes, which include diffraction over the terrain, ducting through the atmosphere, and scattering by rain. It is a complete revision of a previous study wherein preliminary analysis of these phenomena was presented without taking the specific terrain into account. The predicted results concerning diffraction are consistent with measurements and with predictions of the Longley–Rice model. Because of attenuation by the hills, the expected power received through diffraction by a mobile receiver on ground level in Madrid is lower than the interference thresholds (−109 dBm) when the DSN antenna transmits at the normal power of 20 kW. The hills near the DSN antenna also provide much attenuation to the emissions propagated through atmospheric ducting. Considering the low duty cycle (12 percent or less) of about 2 GHz (S-band) transmissions at Robledo, the expected power of emissions propagated through atmospheric ducting does not exceed the receiver interference thresholds more than 0.1 percent of the time. The corresponding effect of rain scattering is estimated to be 0.01 percent of the time. These percentages decrease at larger distances.
Keywords
Details
- Volume
- 42-152
- Published
- February 15, 2003
- Pages
- 1–22
- File Size
- 362.7 KB