646
edits
Changes
From IGEP - ISEE Wiki
no edit summary
X axis represents the time in microseconds or also it can be the sample number.
In the picture below we can see a measurement using a -T 600 modulation over a wall about 2m distance from radar. As we will see later, modulation parameters can be changed, in this case we have selected a modulation ramp with a duration of 600us. Considering that the time to get 2048 samples with the default modulation is 3,471ms and we can see about 20 periods of the sinusoidal signal this means that the dominant sinus shown below is about 45,609KHz 760KHz frequency. The frequency of the IF radar signal is proportional to the distance from the radar to the target (in this case the wall).
[[Image:WAVE 2m -T 600 NEWs.jpg]]<br>
<br>
We will learn later can know at any moment the exactly parameters the radar is working on next chapters how to know the sampling rate and time to get 2048 samples.below lines of the graphs:<br>
<br>
[[Image:WAVE LEGEND NEWs.jpg]]
In this case we can identify on the last line the modulation parameters used to make the measurement: The radar start frequency is 24 GHz with a bandwith of 250MHz and a modulation ramp of 604us. Note that although we have selected 600us the radar has a limitation in discrete values and has been configured with the closest value, in this case 604us. We can see also the sampling rate (590ksps) and the modulation parameter Hzpm (herz per meter) that indicates the IF frequency relation with distance.
The "MEASURES" line indicates a refresh time of 333ms (this means that in this moment we visualise about 3 frames per second) and the points per each transfer are 2048.
The "DISPLAY" line offers the possibility to change the units of the x-axis. We can select time or samples.
=== What's This? ===
<br>
[[Image:WEB-WAVEwhatsthis.jpg]]<br>
== Basic FMCW Radar Theory ==
