Four channel alphasat ka- and q- band beacon receiver station


Andrej Vilhar, Andrej Hrovat, Sebastijan Mrak, Urban Kuhar, Goraz Kandus
Institut Jožef Stefan


ABSTRACT:
Four channel alphasat ka- and q- band beacon receiver station
A newly established beacon receiver station at Jozef Stefan Institute in Ljubljana will be described. The purpose is to measure the 19.7 GHz and 39.4 GHz beacons and their cross-polar components from Alphasat and to contribute to the actions of the ASAPE group (Group of the AlphaSat Aldo Paraboni propagation Experimenters). In the presentation, we shall discuss the design of the receiver system, describing separately the RF front-end, the digital receiver and the pointing system, which is required due to the inclined orbit of the satellite. The receiver is operational since August 2015. First trials have already been conducted. Example received signal power measurements obtained on rainy days will be shown and analysed in comparison to the captured rain intensity.


POVZETEK:
Štirikanalna Alphasat sprejemna postaja za meritve svetilniških signalov v Ka- in Q-pasu
V predstavitvi bomo opisali novo sprejemno postajo na Institutu Jožef Stefan v Ljubljani. Njen namen je meriti svetilniške signale in njihove pravokotno polarizirane komponente s satelita Alphasat, pri frekvencah 19.7 GHz in 39.4 GHz. Z rezultati želimo prispevati k aktivnostim evropske skupine ASAPE (Group of the AlphaSat Aldo Paraboni propagation Experimenters). Predstavili bomo delovanje sprejemnega sistema, ki ga bomo razčlenili na radijski del, na digitalni detektor in na sledilni sistem, ki je potreben zaradi rahlo nagnjene tirnice satelita. Postaja deluje od Avgusta 2015. Prvi poskusi so bili že uspešno opravljeni. Pokazali bomo primere meritev jakosti signala, pridobljenih ob deževnem vremenu in jih primerjali z intenzivnostjo padavin.