Well, I do not understand your problem. As impulse function delta[n-k] will be 1 if and only if n=k, therefore you will get impulse only in case your t=tau. You must convert either the units in ns or s.

Hi! I didn't understand exactly what you want. But, may be this will help:

%

d = [2 3 6 8];

c = 3e8;

tau = d/c;

t = [0:0.1:10]/c;

for i=1:length(tau)

X = dirac(t-tau(i));

idx = X == Inf; % find Inf

X(idx) = 1; % set Inf to finite value

stem(t,X); hold on

end

%

Mohammed Saquib Khan Thank you sir, This is what i mean, I have set the range of tau by some other method, but delta function gives impulse on certain values of distances and doesnt give the impulse of other values of d. I will try this one. Thanks for the help