Simultaneous Nadir Overpasses (SNOs) between GOES-17 and FY3D
TLE Epoch: 2021 7 9.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 07/09/2021   10:42:47   (   0.03,-137.18) (  -0.15,-136.44)   85.08                80
 07/11/2021   22:45:26   (  -0.02,-137.17) (   0.02,-137.06)   13.24                80
 07/14/2021   10:50:35   (   0.03,-137.16) (   0.13,-137.64)   54.77                80
 07/15/2021   10:28:57   (   0.03,-137.15) (  -0.92,-133.06)  467.52                80
 07/16/2021   22:53:13   (  -0.03,-137.13) (  -0.30,-138.25)  128.21                80
 07/17/2021   22:31:35   (  -0.03,-137.12) (   0.75,-133.67)  393.58                80
 07/19/2021   10:55:42   (   0.02,-137.10) (   0.40,-138.85)  198.51                80
 07/20/2021   10:34:05   (   0.01,-137.08) (  -0.65,-134.26)  322.51                80
 07/21/2021   22:58:20   (   0.01,-137.05) (  -0.56,-139.46)  275.27                80
 07/22/2021   22:39:23   (   0.01,-137.03) (   0.50,-134.88)  245.38                80