Simultaneous Nadir Overpasses (SNOs) between GOES-17 and FY3D
TLE Epoch: 2021 9 26.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 09/26/2021   10:46:18   (   0.04,-137.21) (  -0.19,-136.05)  131.98                80
 09/27/2021   23:05:14   (  -0.04,-137.21) (  -0.93,-141.27)  462.19                80
 09/28/2021   22:48:56   (  -0.04,-137.20) (   0.08,-136.67)   60.60                80
 10/01/2021   10:48:45   (   0.03,-137.19) (   0.04,-137.25)    7.84                80
 10/03/2021   22:51:23   (  -0.02,-137.16) (  -0.15,-137.88)   81.32                80
 10/04/2021   22:35:04   (  -0.02,-137.14) (   0.86,-133.28)  440.76                80
 10/06/2021   10:53:50   (   0.01,-137.12) (   0.32,-138.45)  150.92                80
 10/07/2021   10:37:32   (   0.02,-137.11) (  -0.69,-133.85)  370.74                80
 10/08/2021   22:56:28   (  -0.02,-137.08) (  -0.44,-139.07)  226.17                80
 10/09/2021   22:40:10   (  -0.02,-137.06) (   0.58,-134.47)  294.91                80