Earth Station Parameters — Lesson 4

This lesson covers the key parameters of earth stations, focusing on the G/T ratio that defines the receive characteristics of an antenna. It explains the challenges of measuring this ratio, especially for large antennas, and introduces different methods for its calculation. The lesson also discusses the use of radio stars and cold sky as reference noise sources for these measurements. It further explores the indirect method of calculation for medium and small antennas, and the comparison method for small and medium stations. The lesson concludes with an explanation of how to measure and calculate the Effective Isotropic Radiated Power (EIRP) of a system.

Video Highlights

00:18 - Introduction
01:32 - Use of radio stars as noise sources for G/T measurements
01:45 - How radio stars emit radio noise in various frequencies
05:13 - How to measure G/T using radio stars
09:46 - Need for certain corrections in G/T measurements
11:34 - Indirect method for medium and smaller antenna
16:35 - Indirect method using satellite itself
18:56 - Comparison Method
21:48 - How to measure the EIRP
25:03 - Summary

Key Takeaways

- The G/T ratio is a crucial parameter for earth stations, defining their receive characteristics.
- Measuring the G/T ratio can be challenging, especially for large antennas.
- Radio stars and cold sky can serve as reference noise sources for these measurements.
- Different methods, including direct, indirect, and comparison methods, are used to calculate the G/T ratio.
- The EIRP of a system can be partly measured and partly calculated.