Not a video and not a SAM system, but I think a good overall Radar documentation also fits in this information gathering topic:
[url=---http://www.radartheory.8m.com/basics.html#basic]Radar Theory and Systems[/url]

Edit: Modified the direct link due to pistons79 virus warning - I did not get any such warnings, not at home and not at the office; remove the leading dashes in the link at your own risk wink