05. CFAR 2D

The 2D CFAR is similar to 1D CFAR, but is implemented in both dimensions of the range doppler block. The 2D CA-CFAR implementation involves the training cells occupying the cells surrounding the cell under test with a guard grid in between to prevent the impact of a target signal on the noise estimate.

2D CFAR Steps

You won't need to implement a 2D-CFAR yet, but you will implement a 2D CFAR on the range doppler output for your final project! The following steps can be used to implement 2D-CFAR in MATLAB:

1. Determine the number of Training cells for each dimension Tr and Td. Similarly, pick the number of guard cells Gr and Gd.
2. Slide the Cell Under Test (CUT) across the complete cell matrix
3. Select the grid that includes the training, guard and test cells. Grid Size = (2Tr+2Gr+1)(2Td+2Gd+1).
4. The total number of cells in the guard region and cell under test. (2Gr+1)(2Gd+1).
5. This gives the Training Cells : (2Tr+2Gr+1)(2Td+2Gd+1) - (2Gr+1)(2Gd+1)
6. Measure and average the noise across all the training cells. This gives the threshold
7. Add the offset (if in signal strength in dB) to the threshold to keep the false alarm to the minimum.
8. Determine the signal level at the Cell Under Test.
9. If the CUT signal level is greater than the Threshold, assign a value of 1, else equate it to zero.
10. Since the cell under test are not located at the edges, due to the training cells occupying the edges, we suppress the edges to zero. Any cell value that is neither 1 nor a 0, assign it a zero.

2D CFAR Quiz

Further Research

You can find out more about this [here]( http://www.radartutorial.eu/01.basics/False%20Alarm%20Rate.en.html
) and here .