Simultaneous Nadir Overpasses (SNOs) between GOES-17 and FY3D
TLE Epoch: 2021 1 18.  Predictions up to the next  14.0 days:

     Date     Time(GOES-17)   GOES-17 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 01/18/2021   22:45:45   (   0.00,-137.21) (  -0.23,-138.25)  118.35                80
 01/19/2021   22:29:28   (   0.01,-137.21) (   0.82,-133.67)  404.31                80
 01/21/2021   10:50:57   (  -0.01,-137.21) (   0.36,-138.85)  186.82                80
 01/22/2021   10:29:19   (  -0.01,-137.21) (  -0.65,-134.26)  335.30                80
 01/23/2021   22:50:56   (   0.01,-137.20) (  -0.53,-139.48)  260.59                80
 01/24/2021   22:34:40   (   0.02,-137.19) (   0.53,-134.90)  261.08                80
 01/26/2021   10:56:08   (  -0.02,-137.17) (   0.64,-140.08)  331.44                80
 01/27/2021   10:34:32   (  -0.02,-137.16) (  -0.42,-135.50)  189.68                80
 01/28/2021   22:56:09   (   0.02,-137.14) (  -0.76,-140.72)  407.82                80
 01/29/2021   22:39:52   (   0.02,-137.12) (   0.24,-136.13)  113.04                80
 01/31/2021   11:01:20   (  -0.02,-137.09) (   0.93,-141.31)  480.32                80