Simultaneous Nadir Overpasses (SNOs) between GOES-17 and FY3D
TLE Epoch: 2021 7 12.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 07/14/2021   10:50:34   (   0.03,-137.16) (   0.17,-137.63)   54.18                80
 07/15/2021   10:28:57   (   0.03,-137.16) (  -0.88,-133.05)  468.22                80
 07/16/2021   22:53:13   (  -0.04,-137.14) (  -0.28,-138.26)  127.46                80
 07/17/2021   22:31:35   (  -0.03,-137.13) (   0.77,-133.67)  394.40                80
 07/19/2021   10:55:42   (   0.03,-137.11) (   0.44,-138.84)  197.48                80
 07/20/2021   10:34:04   (   0.02,-137.09) (  -0.61,-134.25)  323.65                80
 07/21/2021   22:58:21   (  -0.01,-137.06) (  -0.54,-139.46)  274.00                80
 07/22/2021   22:36:43   (   0.01,-137.04) (   0.52,-134.88)  246.57                80
 07/24/2021   10:58:10   (  -0.02,-137.01) (   0.65,-140.06)  346.82                80
 07/25/2021   10:41:52   (  -0.02,-136.99) (  -0.35,-135.46)  173.94                80