Simultaneous Nadir Overpasses (SNOs) between GOES-15 and FY3D
TLE Epoch: 2021 7 1.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 07/02/2021   22:15:41   (   0.02,-128.14) (  -0.30,-129.64)  170.19                80
 07/03/2021   21:59:22   (   0.01,-128.12) (   0.69,-125.04)  350.68                80
 07/05/2021   10:18:09   (  -0.03,-128.16) (   0.45,-130.22)  234.74                80
 07/06/2021   10:01:52   (  -0.02,-128.13) (  -0.60,-125.63)  285.47                80
 07/07/2021   22:20:48   (   0.04,-128.01) (  -0.58,-130.84)  323.10                80
 07/08/2021   22:04:30   (   0.04,-127.97) (   0.42,-126.25)  196.92                80
 07/10/2021   10:23:17   (  -0.06,-128.01) (   0.72,-131.42)  389.38                80
 07/11/2021   10:07:00   (  -0.05,-127.97) (  -0.33,-126.84)  130.19                80
 07/12/2021   22:25:55   (   0.06,-127.83) (  -0.90,-132.04)  479.60                80
 07/13/2021   22:09:37   (   0.05,-127.80) (   0.15,-127.45)   40.01                80