Well, I dunno. I'm no expert. I started this thread because I wanted to learn a lot more about mining this data to get to the facts. Here's what I see in your file:
Your launch site is about 5,000 feet above sea level? (Colorado?)
Accell velocity data got to zero about 12.6 seconds
Baro says apogee was between 12.6 & 13.2 seconds - so it matches the accelerometer well
(if the vent holes were not right wouldn't it force accel & baro data to disagree?)
Apogee channel event went off at 13.7 seconds as you say, so ~1 second after both sensors sensed apogee
How was your Raven programmed for apogee trigger?
What ematch did you use for apogee? Powder type? Amount? Enclosure?
Here's a far out idea: Were you the one making the video? Maybe your position relative to the flight gave a bit of an illusion that it was on the way down when it was still more-or-less horizontal at apogee? Again, I dunno. But I have seen something like that. What do you think?
Yes, Colorado. I was using Quest Q2G2 ignitors and 1 gram of Goex FFFFG, Raven apo set to default increasing baro - also had 15sec delay on Cesaroni motor for ALT Apogee charge. Both charges fired but I believe they went simultaneously. I was not the one filming it, not sure who did but I found this video on the COSROCS webpage.
I looked at the video, and I think that a lot of the apparent lateness is from the optical illusion you get when the rocket is overhead and flying upward and away from you with a decent horizontal apogee speed, and it looks like it's descending. As it arcs over, the curvature of the flight even makes it look like it's speeding up when really its just that you're getting a more side-on view. 1/4" is a pretty huge vent hole, so I doubt that the internal pressure was lagging much. The accel-based apogee detection agreed with the baro data as well.
Adrian, you may be right. I only have three launches with this rocket, the first apogee went unobserved as it was on a CTI 6 grain J, and the last was on another CTI I which didn't give me the illusion. What really matters though, is that the Raven worked great and brought the rocket down successfully in all three cases.
I did not time the sound of the charge going off in the video, but he reported it lined up with the Raven data pretty good. The apogee (baro) was almost exactly 2100 feet. I looked at how long he spent within 50 feet of that just to get an arbitrary sense of how long it was going more horizontal than vertical. It got to ~2050 feet at about 11 seconds and fell back to 2050 feet at almost 15 seconds. So it spent a long time near apogee. Maybe this 'hang time' explains it?
Great observation cvanc. That seems to corroborate what Adrian said with his falling rock illusion theory.