Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 9 18.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 09/19/2017   22:40:36   (  -0.29,-135.31) (  -1.10,-138.94)  413.70                80
 09/20/2017   22:24:31   (  -0.30,-135.33) (  -0.12,-134.40)  104.81                80
 09/22/2017   10:46:20   (   0.28,-135.40) (   1.27,-139.68)  488.79                80
 09/23/2017   10:24:57   (   0.29,-135.41) (   0.22,-135.16)   28.82                80
 09/25/2017   22:28:10   (  -0.28,-135.39) (  -0.41,-135.93)   61.70                80
 09/26/2017   22:12:05   (  -0.29,-135.40) (   0.58,-131.40)  455.95                80
 09/28/2017   10:33:55   (   0.27,-135.46) (   0.57,-136.67)  138.71                80
 09/29/2017   10:12:31   (   0.28,-135.47) (  -0.48,-132.15)  377.97                80
 09/30/2017   22:34:28   (  -0.26,-135.42) (  -0.69,-137.46)  232.41                80
 10/01/2017   22:18:24   (  -0.26,-135.42) (   0.30,-132.93)  284.52                80