You can do this with the pdist2 function. For latitude and longitude, usually the haversine method is used. Google it if you want the details. Unfortunately, haversine is not provided as a distance option in pdist2. But, the function is easy to write and can be passed in as a handle to pdist2.
Here's an example using the latitudes and longitudes for five Canadian Cities. You'll need to do some post processing to determine "closeness" between cities (or antenna platforms as noted in your question).
lat = [43.653214 48.429986 50.442545 49.872654 46.811837];
lon = [-79.384051 -123.368147 -104.61133 -97.163108 -71.208415];
D(i,i+1:end) = pdist2(M(i,:), M((i+1):end,:), @haversine);
function [dist] = haversine(ZI, ZJ)
dist = 2 * 6371 * asin(sqrt(sind((lat2-lat1)/2)^2 + cosd(lat1) * cosd(lat2) * sind((lon2 - lon1)/2)^2));