code analysis for antenna radar

Sorry if there isnt much context, let me know if so. I want to understand the code. this code is designed for radar sensor to detect object.

I have taken small part of full code. what are those two arrow pointed code doing?

%Define constants

N_txrx = size(TxRxPairs,1);

N_freq = length(freq);

c = 3e8; %SOL (m/s)

Nfft = 2^(ceil(log2(size(freq,2)))+1); <-------------- ? log? freq, 2? +1?

Ts = 1/Nfft/(freq(2)-freq(1)+1e-16); %Avoid nan checks <------- ? what is "(freq(2)-freq(1)+1e-16)"

time_vec = (0:Ts:Ts*(Nfft-1));

dist_vec = time_vec*1.5e8; %distance in meters

[Sara James]

The Nfft line is calculating the next power of 2. The Ts line is calculating what appears to be a sample time. The addition of the 1e-16 appears to be a guard to prevent division by 0 if the difference of freq(2) and freq(1) is too small.