R-DAS APOGEE - RECOVERY SYSTEM DEPLOYMENT DELAY AND VARIANCE
The following table displays the variance between the apogee altitude recorded by the RDAS on each of my personal flights, and the altitude at which the recovery system was deployed. The issue of the variance was raised on the RDAS mailing list, and I thought it would be useful to track the variance in my flights.
As can be seen, the variance is minimal, certainly well within the tolerances one would expect for a unit of this type.
|Flight #||Version||Apogee||Apogee - Deployment Altitude difference||Apogee - Deployment altitude time difference||Apogee - Deployment altitude variance|
|1||2.3||1050 feet||0 feet||0.8 seconds||0%|
|2||2.3||1242 feet||0 feet||0 seconds||0%|
|3||3.0||1758 feet||0 feet||-0.4 seconds||0%|
|4||3.0||792 feet||27 feet||1.3 seconds||3.4%|
|5||3.0||1504 feet||75 feet||2.2 seconds||5%|
|6||3.0||804 feet||50 feet||2.1 seconds||6.2%|
|7||3.1||2352 feet||0 feet||0.7 seconds||0%|
|8||3.1||2495 feet||27 feet||1.6 seconds||1.1%|
|9||3.2||1392 feet||0 feet||0.8 seconds||0%|
|10||3.2||838 feet||0 feet||0.2 seconds||0%|
|11||3.2||1466 feet||0 feet||0 seconds||0%|
|12||3.2||1641 feet||0 feet||0 seconds||0%|
|13||3.2||1762 feet||0 feet||0 seconds||0%|
|14||3.2||1365 feet||0 feet||0 seconds||0%|
|Average:||13.8 feet||0.72 seconds||1.21%|
From version 3.2 of the R-DAS firmware, the apogee detection routine has been modified by AED, and the modification reduces the delay between apogee detection and deployment initiation. If the smallest possible variation between apogee detection and deployment initiation is required (which is generally the case with most rocketeers), then version 3.2, or the even more recent version 3.3 of the R-DAS firmware should be used.
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