Simultaneous Nadir Overpasses (SNOs) between GOES-15 and FY3D
TLE Epoch: 2021 1 8.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 01/08/2021   09:54:11   (   0.20,-128.15) (  -0.39,-125.51)  300.74                80
 01/09/2021   22:18:27   (  -0.25,-128.18) (  -0.82,-130.72)  290.18                80
 01/10/2021   21:56:51   (  -0.23,-128.16) (   0.23,-126.14)  230.11                80
 01/12/2021   10:20:58   (   0.27,-128.09) (   1.02,-131.30)  367.69                80
 01/13/2021   09:59:21   (   0.25,-128.07) (  -0.04,-126.73)  152.49                80
 01/14/2021   22:23:38   (  -0.29,-128.09) (  -1.18,-131.93)  439.09                80
 01/15/2021   22:02:01   (  -0.27,-128.07) (  -0.12,-127.36)   80.95                80
 01/18/2021   10:07:12   (   0.29,-127.97) (   0.31,-127.94)    3.99                80
 01/20/2021   22:09:52   (  -0.31,-127.97) (  -0.46,-128.57)   69.01                80
 01/21/2021   21:48:15   (  -0.29,-127.95) (   0.60,-123.99)  450.73                80