kopia lustrzana https://github.com/proto17/dji_droneid
Updated Home (markdown)
rodzic
4363129da5
commit
c2ca05144e
43
Home.md
43
Home.md
|
@ -129,10 +129,49 @@ sample_rate = 30.72e6;
|
|||
start_time = 2.722209;
|
||||
burst_duration = 0.00080729;
|
||||
|
||||
start_time_samples = int(start_time * sample_rate);
|
||||
burst_duration_samples = int(burst_duration * sample_rate);
|
||||
start_time_samples = round(start_time * sample_rate);
|
||||
burst_duration_samples = round(burst_duration * sample_rate);
|
||||
|
||||
fprintf(1, 'Start sample offset: %d, sample duration: %d\n', start_time_samples, burst_duration_samples);
|
||||
```
|
||||
|
||||
Running this script you should get the following output:
|
||||
```
|
||||
Start sample offset: 83626260, sample duration: 24800
|
||||
```
|
||||
|
||||
Next the samples need to be read from the file they were recorded to. Using the function in [5] that looks like this:
|
||||
```
|
||||
file_path = '/path/to/your/file.fc32';
|
||||
sample_rate = 30.72e6;
|
||||
|
||||
start_time = 2.722209;
|
||||
burst_duration = 0.00080729;
|
||||
|
||||
start_time_samples = round(start_time * sample_rate);
|
||||
burst_duration_samples = round(burst_duration * sample_rate);
|
||||
|
||||
samples = read_complex_floats(file_path, start_time_samples, burst_duration_samples);
|
||||
|
||||
length(samples)
|
||||
```
|
||||
|
||||
The output of which should look like:
|
||||
```
|
||||
ans = 24800
|
||||
```
|
||||
Which means that `samples` now contains 24,800 complex samples.
|
||||
|
||||
Now that you have the samples, it's a good idea to plot them to make sure that you really got a full burst. An easy way to do this is to plot the magnitude squared (`abs(samples).^2`). Add the following to the script above:
|
||||
|
||||
```
|
||||
figure(1);
|
||||
plot(10 * log10(abs(samples).^2));
|
||||
```
|
||||
|
||||
In my case the plot looks like this
|
||||
![image](https://user-images.githubusercontent.com/4240543/163081765-bdb3debf-0363-465d-8b1e-92d645d0ddd0.png)
|
||||
|
||||
|
||||
[4] https://github.com/gnuradio/gnuradio/blob/main/gr-utils/octave/read_complex_binary.m
|
||||
[5] https://github.com/proto17/dji_droneid/blob/main/matlab/read_complex_floats.m
|
Ładowanie…
Reference in New Issue