Increasing df accuracy

1

A lot of high end df systems claim use of super resolution algorithms with accuracy of 1 deg.
How can that be possible ?

  1. Does increasing sample rate lets say by 10 then max of rtl sdr which is around 2 msps to 20 msps will have an impact on resolution accuracy ?
  2. Limitation of 8 degrees is using rayleigh super resolution . Any paper or maths behind this super resolution ?
2

  1. It could have an effect if the bandwidth of your signal is that large. But for narrowband signals there will be no real effect.

  2. Any textbook on MUSIC or similar algorithms will be useful. The biggest improvement to resolution comes via adding more elements (and hence RF channels) to the array. But that also comes at the disadvantage of more computational processing required, and also a larger array.