- This topic has 55 replies, 13 voices, and was last updated 16 years, 11 months ago by
Warren B. Musselman.
Warren B. Musselman.-
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Jeffrey Joe Hinton
North site AOO is a two nautical mile radius for 20,000′ AGL and below, and it is a five nautical mile radius when the 35,000′ AGL windows were used.
Warren B. Musselman
So a 4 mile cylinder to 20K and a 10 mile cylinder to 35K. Excellent
W
edward
Following John W.’s logic that it is really hard to drift 15,000′ away on a 9k boost another data point is John Bixler’s Junior flight on Friday. He flew a 54mm diameter rocket to 22,312′ and recovered 1.72 miles due east. Now a 54mm rocket has a lot more surface area, as well as a bigger main parachute to drift on and didn’t go nearly as far as 15,000′ away. Just another data point.
Edward
James Russell
Ed it was only 1.3-1.5 miles away not 3. a lot of the points on the map are not clear as to what they are.
Ed Dawson
I’m glad to see that Adrian is not looking at temperate ‘adjustments’ for any record claims. As pointed out, this would be a huge difference to the altitudes seen from altimeters that have been used for Tripoli and club records over the last decade or so. In some of the posts I have seen claims that temperature adjusted data is about 12% higher than non-adjusted. If this were the case then it would be a very apples-to-oranges comparison.
I should point out that there are “temperature compensated” pressure sensors, and “uncompensated” sensors. I am not aware of any rocket altimeters that currently use the uncompensated type. Warren, when you talk about your discussions with Jim Amos, I assume that he is talking about his use of an “integrated” (temperature compensated) sensor as opposed to any temperature compensation he is doing in his firmware.
My personal desire is for altimeters that are similar in performance as opposed to extreme MSL accuracy. As Scott pointed out, this is a hobby. I’m not landing a 747. What also remains to be seen is if there can be manufacturing consistency on a $100 part. It only takes a few millivolts of noise to make a huge difference in altitude. What I’m saying is that I want repeatability and consistency as opposed to extreme accuracy. If new altimeters come out that are more accurate and temperature adjusted, then there should be a new set of records, or a new understanding of how the records are set. The Parrot may be this new product in a new world of altimeters. Right now the Parrot is still in beta test and there is only one person using it to report altitudes or claim records. Given time this may be the direction of all altitude records.
Finally, I’ve been thinking about my earlier comment about “witnessing” the flight if I were the LCO or RSO. I would not in good conscious be able to witness this altitude shot for a Tripoli record. All I could agree to is that I saw a stable rocket presented to the RSO, the skies were clear, and the rocket was launched. Beyond that nothing I say should make any difference (just like in this forum).
Warren B. Musselman
The discussion I had with Jim was more related to the fact that the standard atmosphere model is calibrated at a specific temperature – I can’t recall what it is, but I think it’s right at freezing. However, most flights are in warmer weather and compensation is necessary to adjust the reading for the warmer temperature. This is above and beyond any internal compensation provided by the sensor. Jim achieves this by normalizing the data for 70 degrees or thereabouts and told me that all the manufacturers adjust the SAM based on that. Of course, I may have misunderstood the conversation.
As for witnessing a record flight – I believe the rules state that two NCR members in good standing must witness the altitude reading directly off the altimeter immediately upon recovery. I believe that alone would disqualify the Parrot unless Adrian were to do the data download at the LCO table immediately upon recovery. My biggest recommendation to him is to provide a direct reading of altitude either via beeps or flashing LED as other manufacturers do or a plug-in LCD display that reads the raw altitude. I think it’s an excellent product, but as it stands I see far too much push-back due to the after-action data download required to read the altitude. I very much like the accelerometer data that goes with the baro data though.
W
Murdock
My biggest recommendation to him is to provide a direct reading of altitude either via beeps or flashing LED as other manufacturers do or a plug-in LCD display that reads the raw altitude. I think it’s an excellent product, but as it stands I see far too much push-back due to the after-action data download required to read the altitude. I very much like the accelerometer data that goes with the baro data though.
W
If Adrian logged in using hyperterminal and showed the raw data from the altimeter without pulling it into excel or the like would that be acceptable? That’s not really any different than a plugin LCD type display. You could build an LCD that does a small 1.2x multiplier on whatever the real output is and cheat that way too.
To me, Adrian’s altimeter presents more than enough data to support itself, even with the processing. Its almost as if the altimeter is being dis-regarded because its too accurate or provides too much data at a granular level.
I don’t dismiss everyone’s concerns about data being presented after the fact, by the manufacturer, etc. As far as the output though, it think that should be a non-issue.
Chris
edward
So after reading over this I think there probably is a simpler solution than banning an altimeter flown by the manufacturer. When digital photography came of age it just so happened that all truth in photograph was lost. You really couldn’t believe your eyes anymore because a good enough person could manipulate a photo seamlessly. This had an impact on crime scene photos and ones presented in courts. How could you trust the photos? Well, every camera sensor is different and all have a few dead pixels here and there and some that are hot, etc. The one I’m familiar with (Canon) took the step of having a kit where you took some photos under specific lighting and backgrounds, and those were your template images. Any photos you took after were compared to those to determine if they had those same dead and hot pixels. It would be really hard to alter an image and not wipe out a couple of those – so it was easy to verify. It also encoded other camera specific information into it.
Why can’t something like this be developed for altimeters? Before the flight you go to the LCO, RSO, or an observer and they type in their password into the altimeter programming software. This encodes the data on the altimeter so it can only be read with that password. Then we have a standardized program for interpreting the data. You take that altimeter to the LCO and observer and download and decode it. That way the owner doesn’t have control over the datastream.
After writing all this it seems like a lot for a hobby…but who knows….
Edward
Warren B. Musselman
I’m all for Adrian’s Parrot to be honest about it and I do believe it is more accurate and provides additional data in the form of the 3 axis accelerometer to back up the baro altitude.
That said, I don’t believe TRA accepts manufacturers flying their own hardware on record attempts. I believe I’m going to wait to see what shakes out with the TRA Records Committee before I do anything about NCR rules – they stand as they currently are until then and even then it will take a discussion of the Executive Committee and some of the stakeholders including John Wilke, Adrian and perhaps others with an interest in this issue before any rule changes are made.
Warren
Anonymous
I have an inherent conflict of interest, I wasn’t there, and I recuse myself. I’m sure smarter folk than I will apply the rules (we do have rules somewhere) and whatever they decide, go for it. This is a hobby, not a grand jury 8)
Jeffrey Joe Hinton
Warren B. Musselman
edward
James Russell
Ed Dawson
Murdock
Anonymous
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