Sunday, April 10, 2016

Determining the radiant of a meteor using Graves radar (III): the details

In my previous post I explained what we did and what results we got. In this post I'll show you the technical details behind the experiment, with some hints and tips in the case you want to replicate it. As a guide, I'll solve a meteor step by step, from the wav file to the radiant, and then, the final orbit around the sun.

Friday, April 8, 2016

Determining the radiant of a meteor using Graves radar (II)

One year ago, I published my experiences about determining the radiant of a meteor using Graves radar. If you read it (I hope you really did it) a question arises immediately: What about three receivers? Fortunately David, amateur astronomer and ham radio operator also known as EA1FAQ joined the team so we could answer this question.

Figure 1: Transmitter and receivers location

We had some doubts. Could the same meteor head echo be received simultaneously by three different stations? some calculations and simulations were made with many interesting results.

Saturday, January 9, 2016

Wideband Quadrantids using Graves radar

Recently I realized one of the most limiting factors while measuring doppler head echoes is the limited bandwidth of SSB receivers. Sometimes you receive a really long head echo appearing at 3000 Hz and going down to 1000 Hz, the rest frequency when you tune 143.049 USB with Graves. And you wonder: how high the doppler can be? To answer that question I made an "special IF filter" for my FT-817. The filter is just a piece of coaxial, so I can receive the whole receive bandwidth. A dummy filter.