Shoot-out at the Super 8 Motel W. Morgan, T. Redding, L. Fleming Presented at the 2016 IOTA Annual Meeting Oklahoma State University, Stillwater, OK July 29, 2016 by Ted Blank

2 Background Observation (by Terry Redding, at the 2015 IOTA annual meeting): Observation (by Terry Redding, at the 2015 IOTA annual meeting): We had in our possession three different We had in our possession three different video time inserter types, video time inserter types, each with an out-dated almanac each with an out-dated almanac Suggestion: a “shoot-out” to compare them Suggestion: a “shoot-out” to compare them

3 The Time Inserters Type Kiwi OSD IOTA-VTI IOTA-VTI v3 Type Kiwi OSD IOTA-VTI IOTA-VTI v3 Ser. Number Ser. Number Reference name K1077 VT127 VT600 Reference name K1077 VT127 VT600 Owner Fleming Redding Morgan Owner Fleming Redding Morgan Mfgr year ~ Mfgr year ~ Inactive > 1 yr > 2 yr 2 months Inactive > 1 yr > 2 yr 2 months

4 The Experiment (aka “Shoot-out”) Location: the hood of Larry’s Jeep, Location: the hood of Larry’s Jeep, in the parking lot of the Super 8 Motel in the parking lot of the Super 8 Motel The plan: let’s see what happens The plan: let’s see what happens Recorder: iPhone, manned by Terry Recorder: iPhone, manned by Terry The resulting video: The resulting video:

5 Clarifications Because of minimal planning, the video can be hard to follow – thus this report Because of minimal planning, the video can be hard to follow – thus this report This report includes screen captures which will be identified by the time at which they appear in the video. This report includes screen captures which will be identified by the time at which they appear in the video. Example: RT 0:13 Example: RT 0:13 is at Run Time 0 minutes 13 seconds is at Run Time 0 minutes 13 seconds

6 Explanation of Displays Upper display: K1077 information Upper display: K1077 information Lower display: VT127 and VT600 information Lower display: VT127 and VT600 information VT600 was in FullScreen mode, so appears VT600 was in FullScreen mode, so appears on the lowest line on the lowest line VT127 was in TVsafe mode, so appears VT127 was in TVsafe mode, so appears one line higher one line higher Overwrite appears on some of the captures of the lower screen Overwrite appears on some of the captures of the lower screen

7 RT 0:13 Run Time of 0:13 appears in the lower left corner. Run Times have been cropped out of later screen captures. The upper screen displays K1077. The lower screen displays VT127 and VT600.

8 RT 0:39 At 39 seconds after applying power, VT600 has acquired four satellites, sufficient to report time.

9 RT 1:46 VT127 has four satellites, but its GPS requires five satellites before it will report time.

10 RT 2:11 K1077 is in a 30-second reset cycle, and is currently displaying latitude and longitude – so it has a fix.

11 RT 2:27 The reset cycle for K1077 is nearly complete. VT127 has been returned to Position mode. VT127 almanac is more than two years old.

12 RT 2:48 K1077 is reporting time. The field count of 732 indicates that it was reset about 12 seconds earlier.

13 RT 4:06 All three time inserters are reporting time, but they are all different!

14 RT 4:31 The Kiwi OSD requires an external camera to operate correctly. The camcorder being used is about to turn off.

15 RT 4:33 The camera driving K1077 has turned off, and K1077 is no longer providing time.

16 RT 4:40 The video input to K1077 has been restored. The three time inserters agree to millisecond precision, but with integer-second differences.

17 RT 5:10 The almanac download for VT127 has completed, and its hourglass caution has been removed. Its integer-second indication now agrees with VT600, and a message directs the user to correct earlier times.

18 RT 5:27 VT127 was switched to Position mode. It does not appear on the screen because the transition from Time mode can require 3 seconds to complete.

19 RT 5:32 VT1077 has been returned to Time mode, and the correction message from RT 5:27 has been removed.

20 RT 6:59 K1077 had continued to lead the other time inserters by three seconds, so it was Reset It is expected that the ERROR message means that the almanac download has completed.

21 RT 7:11 A second press of the K1077 Reset has initiated the 30-second cycle that precedes a return to displaying time.

22 RT 7:37 K1077 now shows time in agreement with VT127 and VT600, confirming that the “error” shown at RT 6:59 was an almanac update.

23 RT 7:49 The one-second difference in its time: the Position screen only updates at 3-second intervals. VT127 has been switched to Position mode. Note that it now shows a current almanac.

24 RT 7:55 VT600 is now in Position mode. The “last used” indication is not current, consistent with the continuing display of the hourglass. (See RT 7:49)

25 RT 8:03 A Reset cycle was initiated for K1077, and previous times were OK.

26 RT 8:08 Latitude and longitude are displayed for both K1077 and VT600. The positional difference is about 13 metres. If HDOP is 1.5 or less, positional accuracy is typically good enough for IOTA use. For lower HDOP, VT600 will need to run longer, to acquire more satellites.

27 RT 8:12 K1077 has acquired 8 satellites, and the very good HDOP of 1.0.

28 RT 8:33 All three time inserters now agree on time to millisecond accuracy. The experiment was ended a few seconds later.

29 Lessons learned GPS-driven video time inserters are subject to integer-second errors in the inserted time as a consequence of leap second additions. GPS-driven video time inserters are subject to integer-second errors in the inserted time as a consequence of leap second additions. These will correct if 15 minutes of acquisition time precedes event timing. These will correct if 15 minutes of acquisition time precedes event timing. This anomaly is more easily managed by users of the IOTA-VTI than by those using the Kiwi OSD. This anomaly is more easily managed by users of the IOTA-VTI than by those using the Kiwi OSD.

30 Reminders Users of video time inserters are cautioned to: Users of video time inserters are cautioned to: Power up early, so almanacs can update Power up early, so almanacs can update Verify with independent time source (~WWV) Verify with independent time source (~WWV) Li-ion cell makes IOTA-VTI v3 less susceptible Li-ion cell makes IOTA-VTI v3 less susceptible To remain less susceptible, IOTA-VTI v3 users must confirm battery status on startup To remain less susceptible, IOTA-VTI v3 users must confirm battery status on startup Kiwi OSD must be pressed twice to update Kiwi OSD must be pressed twice to update

31 And another really important reminder Another leap second will be added December 31, 2016 (UT) Another leap second will be added December 31, 2016 (UT) Mark your calendar Mark your calendar Review this report, or the video Review this report, or the video Run your video time inserter for at least 15 minutes soon after the insertion Run your video time inserter for at least 15 minutes soon after the insertion