Ionospheric Polarization Techniques for Robust NVIS Remote Sensing Platforms

Abstract

Every year more interest is focused on high frequencies (HF) communications for remotesensing platforms due to their capacity to establish links of more than 250 km without a line ofsight and due to them being a low-cost alternative to satellite communications. In this article, westudy the ionospheric ordinary and extraordinary waves to improve the applications of near verticalincidence skywave (NVIS) on a single input multiple output (SIMO) configuration. To obtain theresults, we established a link of 95 km to test the diversity combining of ordinary and extraordinarywaves by using selection combining (SC) and equal-gain combining (EGC) on a remote sensingplatform. The testbench is based on digital modulation transmissions with power transmissionbetween 3 and 100 W. The results show us the main energy per bit to noise spectral density ratio(Eb/N0) and the bit error rate (BER) differences between ordinary and extraordinary waves, SC,and EGC. To conclude, diversity techniques show us a decrease of the power transmission need,allowing for the use of compact antennas and increasing battery autonomy. Furthermore, we presentthree different improvement options for NVIS SIMO remote sensing platforms depending on therequirements of bitrate, power consumption, and efficiency of communication.