No trig required. Here is the data broken down for you:
Data # / X axis / Y axis / Time
1. 22.137 / -7.188 / 1807.75
2. 22.009 / -7.322 / 1811.75
3. 21.265 / -7.943 / 1819.75
4. 21.138 / -8.06 / 1823.75
5. 20.519 / -8.697 / 1831.75
6. 20.393 / -8.831 / 1835.75
I could go on, but you get the picture. 1 and 2 are your first "double return". Note the timing differential. 3 and 4 are the second. Again, note the time. Also note that it takes 12 seconds from 1 to 3. But only 4 between 1 and 2, and 3 and 4. See, no trig required. Just simple math. Now maybe you can explain how a radar sweeping 360 degrees every 12 seconds could identify something as close as your "double returns" with 4 seconds between hits. It ain't going to happen.
By the way, this data comes from that great icon of TWA800 missile conspiracy kooks, the late CMDR Donaldson. It was good enough for him. Apparently, you know better.