Simultaneous Nadir Overpasses (SNOs) between GOES-17 and FY3D
TLE Epoch: 2021 1 10.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 01/10/2021   10:56:50   (  -0.02,-137.24) (   0.84,-140.97)  426.75                80
 01/11/2021   10:40:33   (  -0.01,-137.24) (  -0.22,-136.40)   96.49                80
 01/12/2021   22:59:30   (   0.00,-137.25) (  -1.00,-141.60)  496.93                80
 01/13/2021   22:43:13   (  -0.01,-137.25) (   0.06,-137.03)   26.30                80
 01/16/2021   10:45:45   (   0.01,-137.25) (   0.06,-137.63)   42.55                80
 01/17/2021   10:24:08   (  -0.01,-137.25) (  -0.94,-133.04)  479.77                80
 01/18/2021   22:45:45   (   0.02,-137.25) (  -0.21,-138.26)  114.61                80
 01/19/2021   22:29:28   (   0.02,-137.25) (   0.85,-133.68)  407.80                80
 01/21/2021   10:50:57   (  -0.01,-137.24) (   0.33,-138.86)  183.87                80
 01/22/2021   10:29:19   (   0.01,-137.23) (  -0.68,-134.27)  338.79                80
 01/23/2021   22:50:55   (  -0.01,-137.23) (  -0.54,-139.47)  256.87                80