Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and FY3D
TLE Epoch: 2022 12 6.  Predictions up to the next  14.0 days:

     Date     Time(NOAA-21) NOAA-21 Lat/Lon Date Time(FY3D) FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 12/07/2022   04:57:09   ( -81.20,-132.50) 12/07/2022   04:55:55  ( -81.20,-132.36)    2.49                74
 12/07/2022   05:47:53   (  81.20,  34.85) 12/07/2022   05:46:42  (  81.20,  34.66)    3.17                71
 12/07/2022   06:38:19   ( -81.20,-157.61) 12/07/2022   06:37:26  ( -81.20,-157.45)    2.74                53
 12/07/2022   07:29:03   (  81.20,   9.74) 12/07/2022   07:28:13  (  81.20,   9.57)    2.91                50
 12/07/2022   08:19:30   ( -81.20, 176.90) 12/07/2022   08:18:58  ( -81.20, 177.07)    2.94                32
 12/07/2022   09:10:14   (  81.20, -15.76) 12/07/2022   09:09:45  (  81.20, -15.91)    2.65                29
 12/07/2022   10:00:40   ( -81.20, 151.79) 12/07/2022   10:00:29  ( -81.20, 151.98)    3.17                11
 12/07/2022   10:51:24   (  81.20, -40.87) 12/07/2022   10:51:16  (  81.20, -41.00)    2.36                 8
 12/07/2022   11:41:50   ( -81.19, 126.69) 12/07/2022   11:42:01  ( -81.20, 126.50)    3.22                11
 12/07/2022   12:32:34   (  81.19, -65.98) 12/07/2022   12:32:47  (  81.20, -66.10)    2.13                13
 12/07/2022   13:23:01   ( -81.20, 101.20) 12/07/2022   13:23:33  ( -81.20, 101.02)    2.99                32
 12/07/2022   14:13:45   (  81.20, -91.47) 12/07/2022   14:14:19  (  81.20, -91.58)    1.83                34
 12/07/2022   15:04:11   ( -81.19,  76.09) 12/07/2022   15:05:04  ( -81.20,  75.93)    2.77                53
 12/07/2022   15:54:55   (  81.19,-116.58) 12/07/2022   15:55:50  (  81.20,-116.67)    1.57                55