EME Calculator

‘TIKALUNA’ GLENBURN, VICTORIA, AUSTRALIA

MOON BOUNCE COMMUNICATIONS and RADIO ASTRONOMY

Doug McArthur

Home Software Picture Galleries EME Echos Projects & Papers Links & Contacts

EME Calculator [EMECalc]

This software, with the addition of a simple level indicator and preferably an in-line switched attenuator, will provide a most accurate way of assessing your equipments' performance.

This software will accurately predict *, to a very high degree;

the level of your own Moon echo's
the level of Echo's you will receive from another Station
the level of Echo's the other Station will receive from you
the level of Sun Noise you and the other Station will receive.
the level of Moon Noise you and the other Station will receive and
the level of received Galactic Noise you will expect to receive with combinations of Sources.

In addition a "How to .." section has been provided to enable you to select the best dish feed type combination as well as answering the vexing question

of "if I increase the size of my existing Dish " will it be worth while?

Most all of the known practical engineering factors that make up the 'EME Budget' have been included.

You can also reverse engineer and thus define a possible problem area that can then be improved.

If the calculations provided by this software do not coincide fairly closely with what you are achieving, then you have some area that can be improved.

The software is a tool to determine that area for improvement.

It is not a problem with the software … it is your job to find out why there is a difference!

* Notes

Although this software provides the Engineering data pertaining to the 'EME Budget', factors outside this can influence the end result.

These are mostly related to ionosphere disturbances and will produce shifts in polarisation (Faraday rotation) as well as other aberrations of the received signal.
the affects may not as dramatic as one can be led to believe and are generally more prevalent on the lower frequencies.
The magnitude of Faraday rotation cannot be predicted accurately, but its affect can be significantly reduced (or eliminated) by employing circular polarisation.
Polarisation off-set is always present when working distant stations. It can be overcome (or even eliminated) by using circular polarisation (where practical) noting that this will inherently cause a 3 dB system performance degradation. Polarisation off-set is often mistaken as Faraday rotation.

When using linear polarisation, it is highly desirable to match the path commensurate with the Station you are working at the time. (Software can accurately predict the offset .. refer VK3UM EME Planner)