Recording and Analysis Boost Satellite Ground Segment Monitoring

Introduction

Satellite operators face increasing risks of radio-frequency (RF) interference. For example, terrestrial RF transmission applications such as cellular backhaul may operate on the critical frequencies used by satellite up- and downlinks. The possibility of RF interference between network operators adds to the challenges of ensuring a high quality of service for customers. 

In-orbit testing during satellite commissioning and ongoing quality-of-service checks must capture a record of what transpired in the RF signal environment with operational satellite  

up- and downlinks. Recent developments in commercial high-throughput satellites (HTS) and highresolution Earth observation satellites operating from low-Earth orbit (LEO) require much higherbandwidth satcom links operating at millimeter-wave frequencies at Ka-band and higher. 

Recent advances in high-throughput satellites operating from geostationary equatorial orbit (GEO) and medium-Earth orbit are another factor. To meet their needs, wider transponder bandwidths used in digitally regenerative payloads must capture wider swaths of spectrum — up to and sometimes over 1 GHz — all at once for later processing and analysis.

The Keysight line of modular, high-speed streaming digitizers and arbitrary waveform generators, coupled with ultra-high-capacity modular storage arrays, connects over fiber-optic links to form the basis of a customizable wideband solutions platform. When configured with application software, the system is suitable for ground segment RF signal capture, recording, and offline analysis. It also has the potential for playback of the signals and their RF environment at the time of capture with very high fidelity.

In-Orbit Testing During Commissioning and Operations

During satellite commissioning and day-to-day satcom operations, operators need signal quality measurements to baseline and periodically recheck RF signal conditions at the ground station. They can store time-stamped captures for post-analysis and historical comparison.

For legacy narrowband transponders, you can use commodity digitizers and readily available spectrummonitoring software from various providers or develop the tools in-house. However, the latest HTS and upcoming Ka and V-band LEO constellations will provide much faster data download speeds, often compressed into shorter periods.

An example is when the LEO satellite approaches its zenith position overhead for the best signal-to-noise ratio (SNR). This orbital profile requires wider transponders or multiple transponders aggregated into a multi-carrier configuration, necessitating much wider snapshot captures in just a few minutes rather than over many hours for a traditional GEO satellite. 

RF playback is not necessary, but the ability to quickly load a file to analyze individual signals occurring on different frequencies and at different times is desired. Keysight’s software tools can load recordings and start the analysis right away. The Keysight record and playback solution enables you to use manual or automated analysis tools.

Wideband Solution Platform

The Keysight wideband solution platform (WSP) consists of several critical pieces of baseband instrumentation. Custom-engineered up- and downconverters provide the necessary frequency translation for the satellite operating bands of interest.

The hardware system combines modular Keysight AXIe and PXIe instruments and components to form an intermediate frequency (IF) or baseband streaming recording system.