Industrial interference and radio astronomy

[摘要] The interferer – victim scenario is described for the case of industrialinterference affecting radio astronomical observatories. The sensitivity ofradio astronomical receivers and their interference limits are outlined. EMCabove 30 MHz is a serious problem for Radio Astronomy. Interferer (CISPR)and victim (ITU-R RA 769) standards are not harmonised. The emissions fromthe interferer and their spectral characteristics are not definedsufficiently well by CISPR standards. The required minimum coupling losses(MCL) between an industrial device and radio astronomical antenna depends ondevice properties but is shown to exceed 140 dB in most cases. Spatialseparation of a few km is insufficient on its own, the terrain must shield> 30–40 dB, additional mitigations such as extra shielding orsuppression of high frequency emissions may be necessary. A case by casecompatibility analysis and tailored EMC measures are required for individualinstallations. Aggregation of many weak rfi emitters can become seriousproblem. If deployment densities are high enough, the emission constraintscan even exceed those for a single interferer at a short distance from theradio observatory. Compatibility studies must account not only for thesingle interferer but also for many widely distributed interference sources.

[学科分类] 电子、光学、磁材料