Tests and results¶

The aim of this part is to demonstrate the proper functioning of the tool. That is, the explanation of how we have shown that the results of all the link budget operations are correct, as well as that the tool is understandable for a user who has never used before.

For that purpose, different test with other students have been carried out. Thus, it has been possible to identify the difficulties of understanding of some aspects. For instance, we have identified some hesitation to understand well what refers each input parameter, and so we could take steps to correct it, and add more explanation in the popup help, or add some diagrams blocks in some tabs in order to have an extra visual aid of the correct placement of each parameter in the process.

Checking results¶

Below are shown the different verification carried out in each tab in order to verify the correct computation implementation.

Services¶

tip. libro y proyecto 2

System Geometry¶

Uplink¶

tip. ejemplos libro 5.4.2 y 5.6.2

Payload¶

Antenna depointing 1¶

In the payload we have two windows menu. The first is the Antenna and the second the transponder. The window antenna, in turn, has the Depointing 1 and Depointing 2 window. Only the first calculations of depointing were performed in the application, being the total depointing angle computation, an additional feature to be performed in further implementations of SatLinkTool. In these first calculations, we have performed the true view angles ($\theta$, $\varphi$), the satellite antenna azimuth angle ($\alpha$) and satellite antenna elevation angle ($\beta$), as well as two auxiliary angles $\alpha$*, $\beta$*. The objective of take this values is to implement in total depointing angle perform.

In order to check if our results are correct, we have compared, using the same inputs values, the results showed in an calculating example of the "Satellite Communications Systems" book (page 496). The figure below show the comparison of the results.

 
<div style="margin-left: auto; margin-right: auto; width: 50em">*Figure * - Comparison of results. In the left side the input values and results for SatlinkTool and in the right the input and results of an example of calculating, found in the book.
</div>

Transponder¶

In SatlinkTool we have transparent payload, with two forms of carriers per transponder: single carrier or multicarrier (only 3 carriers/ transponder was applied). The formulas used for each case are exposed below.

• Single Carrier
  The input is the $IBO$ value, which must be entered by the user, we can perform $OBO$ and $IM$ product equal to zero:
  $${OBO}_{|_{dB}}={IBO}_{|_{dB}}+6-6\cdot exp \left(\frac{{IBO}_{|_{dB}}}{6}\right)$$
  $$IM=0$$
  $${\left(\frac{C}{N}\right)_{IM}}_{|_{dB}}=0$$

$${\left(\frac{C}{N}\right)_{U,sat}}_{|_{dB}} = {\left(\frac{C}{N}\right)_{U}}_{|_{dB}} - {IBO}_{|_{dB}}$$

$${\left(\frac{C}{N}\right)_{D,sat}}_{|_{dB}} = {\left(\frac{C}{N}\right)_{D}}_{|_{dB}} - {OBO}_{|_{dB}}$$

• Multi Carrier - Three carriers drive for transponder.

The input is the $IBO$ value, which must be entered by the user, once we have $IBO$ we can perform the following values:
=>$OBO$, => $IM$, => ${\left(\frac{C}{N}\right)_{IM}}$, => ${\left(\frac{C}{N}\right)_{U,sat}}$, => ${\left(\frac{C}{N}\right)_{D,sat}}$

$${OBO}_{|_{dB}}={IBO}_{|_{dB}}+6-6.4\cdot exp \left(\frac{{IBO}_{|_{dB}}+6}{6.4}\right)$$

$$IM =3 {IBO}_{|_{dB}} +17-6.25 exp \left(\frac{{IBO}_{|_{dB}}+11.75}{6.25}\right)$$

$${\left(\frac{C}{N}\right)_{IM}}_{|_{dB}}={OBO}_{|_{dB}}-IM$$

$${\left(\frac{C}{N}\right)_{U,sat}}_{|_{dB}} = {\left(\frac{C}{N}\right)_{U}}_{|_{dB}} - {IBO}_{|_{dB}}$$

$${\left(\frac{C}{N}\right)_{D,sat}}_{|_{dB}} = {\left(\frac{C}{N}\right)_{D}}_{|_{dB}} - {OBO}_{|_{dB}}$$

Downlink¶

tip. ejemplos libro 5.4.3 y 5.6.3

Overall link¶

h1 References

http://www.eutelsat.com/ (Azimuth and Elevation angles)