Simultaneous Nadir Overpasses (SNOs) between GOES-15 and FY3D
TLE Epoch: 2021 6 27.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 06/27/2021   22:10:33   (   0.00,-128.25) (  -0.03,-128.43)   20.68                80
 06/30/2021   10:13:02   (  -0.00,-128.29) (   0.19,-129.01)   83.32                80
 07/01/2021   09:56:44   (   0.00,-128.27) (  -0.86,-124.43)  437.86                80
 07/02/2021   22:15:40   (   0.01,-128.15) (  -0.30,-129.64)  169.22                80
 07/03/2021   21:59:22   (   0.00,-128.13) (   0.69,-125.04)  351.95                80
 07/05/2021   10:18:09   (  -0.02,-128.18) (   0.46,-130.22)  232.46                80
 07/06/2021   10:01:52   (  -0.02,-128.16) (  -0.59,-125.63)  288.04                80
 07/07/2021   22:20:47   (   0.04,-128.02) (  -0.62,-130.83)  320.64                80
 07/08/2021   22:04:30   (   0.03,-128.00) (   0.44,-126.25)  199.70                80
 07/10/2021   10:23:17   (  -0.05,-128.04) (   0.72,-131.42)  385.59                80