%% time periods
gps = [ 1117332016, 1117371616; ... % Jun 3 2015 02:00:00 UTC - Jun 3 2015 13:00:00 UTC
        1117479616, 1117488616; ... % Jun 4 2015 19:00:00 UTC - Jun 4 2015 21:30:00 UTC
        1117492216, 1117544416; ... % Jun 4 2015 22:30:00 UTC - Jun 5 2015 13:00:00 UTC
        1117571416, 1117591216; ... % Jun 5 2015 20:30:00 UTC - Jun 6 2015 02:00:00 UTC
        1117612816, 1117663216; ... % Jun 6 2015 08:00:00 UTC - Jun 6 2015 22:00:00 UTC
        1117668616, 1117699216; ... % Jun 6 2015 23:30:00 UTC - Jun 7 2015 08:00:00 UTC
        1117710016, 1117737016; ... % Jun 7 2015 11:00:00 UTC - Jun 7 2015 18:30:00 UTC
        1117749616, 1117767616; ... % Jun 7 2015 22:00:00 UTC - Jun 8 2015 03:00:00 UTC
        1117861216, 1117877416; ... % Jun 9 2015 05:00:00 UTC - Jun 9 2015 09:30:00 UTC
        1117886416, 1117897216; ... % Jun 9 2015 12:00:00 UTC - Jun 9 2015 15:00:00 UTC
        1117931416, 1117945816; ... % Jun 10 2015 00:30:00 UTC - Jun 10 2015 04:30:00 UTC
        1117985416, 1117989616; ... % Jun 10 2015 15:30:00 UTC - Jun 10 2015 16:40:00 UTC
        1118041216, 1118086216; ... % Jun 11 2015 07:00:00 UTC - Jun 11 2015 19:30:00 UTC
        1118302216, 1118338216; ... % Jun 14 2015 07:30:00 UTC - Jun 14 2015 17:30:00 UTC
        1120807817, 1120813217; ... % Jul 13 2015 07:30:00 UTC - Jul 13 2015 09:00:00 UTC
        1120887917, 1120893617; ... % Jul 14 2015 05:45:00 UTC - Jul 14 2015 07:20:00 UTC
        1121760017, 1121765417; ... % Jul 24 2015 08:00:00 UTC - Jul 24 2015 09:30:00 UTC
        1121898617, 1121927417; ... % Jul 25 2015 22:30:00 UTC - Jul 26 2015 06:30:00 UTC
        1121931017, 1121986817; ... % Jul 26 2015 07:30:00 UTC - Jul 26 2015 23:00:00 UTC
        1121990417, 1121994017; ... % Jul 27 2015 00:00:00 UTC - Jul 27 2015 01:00:00 UTC
        1122089417, 1122093917; ... % Jul 28 2015 03:30:00 UTC - Jul 28 2015 04:45:00 UTC
        1122096617, 1122129017; ... % Jul 28 2015 05:30:00 UTC - Jul 28 2015 14:30:00 UTC
        1122184817, 1122188417; ... % Jul 29 2015 06:00:00 UTC - Jul 29 2015 07:00:00 UTC
        1122195617, 1122219017; ... % Jul 29 2015 09:00:00 UTC - Jul 29 2015 15:30:00 UTC
        1122368417, 1122372017; ... % Jul 31 2015 09:00:00 UTC - Jul 31 2015 10:00:00 UTC
        1122382817, 1122391817; ... % Jul 31 2015 13:00:00 UTC - Jul 31 2015 15:30:00 UTC
        1122460217, 1122485417; ... % Aug 01 2015 10:30:00 UTC - Aug 01 2015 17:30:00 UTC
        1122543017, 1122552017; ... % Aug 02 2015 09:30:00 UTC - Aug 02 2015 12:00:00 UTC
        1122584417, 1122589817; ... % Aug 02 2015 21:00:00 UTC - Aug 02 2015 22:30:00 UTC
        ];