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Thread: Tiger... just wow

  1. #11
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    Mar 2002
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    Default Re: Tiger... just wow

    Quote Originally Posted by Samuel View Post
    Isn't what they are doing already with the onboard telemetry?
    Civilian GPS does not work well at 500mph and 4 g's, so you will not have accurate data.

    Michael

  2. #12

    Default Re: Tiger... just wow

    Quote Originally Posted by Mluvara View Post
    Civilian GPS does not work well at 500mph and 4 g's, so you will not have accurate data.

    Michael
    I can understand that when traveling 3000 feet per second the sampling rate might not give accurate location. Why or how does the high G effect the units?

  3. #13
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    Default Re: Tiger... just wow

    Quote Originally Posted by Arctic Cat View Post
    I can understand that when traveling 3000 feet per second the sampling rate might not give accurate location. Why or how does the high G effect the units?

    The government has put in place COCOM limits on exportable GPS receivers. They do not want people building missiles with them. Because of this, there is filtering on the data that is output from the receiver. All of the receivers I have used at Reno have a limit that is around 4g's. Basically, if the receiver thinks it moved in one direction too fast, it gives out an invalid solution. Part of this also relates to the bank angle of the aircraft and the view of available satellites.

    Perhaps there is something that will work in this environment, but I have not used one and I'm not willing to try a $20,000 gps receiver experiment out of my pocket to find out. I spoke with someone who is working with the Red Bull air races and since they are pulling 8-10 g's, it's the same.

    Michael
    Last edited by Mluvara; 09-16-2014 at 07:27 AM.

  4. #14

    Default Re: Tiger... just wow

    Quote Originally Posted by Mluvara View Post
    The government has put in place COCOM limits on exportable GPS receivers. They do not want people building missiles with them. Because of this, there is filtering on the data that is output from the receiver. All of the receivers I have used at Reno have a limit that is around 4g's. Basically, if the receiver thinks it moved in one direction too fast, it gives out an invalid solution.

    Perhaps there is something that will work in this environment, but I have not used one and I'm not willing to try a $20,000 gps receiver experiment out of my pocket to find out. I spoke with someone who is working with the Red Bull air races and since they are pulling 8-10 g's, it's the same.

    Michael
    There are other options, too. Its been a little while since I worked on any of this, but if you have a FIXED reference GPS receiver station (even a relatively cheap one), then the mobile stations can use it as one of their inputs in differential GPS mode- a term that used to be popular for the fixed station was "pseudolite," clever huh? When they're operating in that mode using real satellite data combined with a fixed station, you can get extremely accurate and quick geolocation without any special selective availability codes, so long as you're not too far away from the "pseudolite" station.

    Like I said, its been 10+ years since I helped a co-worker set up a system like that and the whole GPS constellation and processing scheme has been updated at least a little since then, but we were getting centimeter-sized watch-circles out of the mobile stations. The big unknowns for something like Reno would be the possibility of drop-outs at longer ranges from the base station, accuracy degradation due to speed and antenna vibration, and things like that. I would never argue that its a case of "go buy some cheap receivers and throw them in the airplanes," but I honestly think its a whole lot less than the $20k per unit high-end receivers. I could see each complete aircraft data *package* including inertial components and telemetry (or logging for post-processing) package being on the order of $20- $30k, but since they could be standardized and re-issued for each race you would only need enough for the size of a heat plus spares and alternates. How painful is a couple hundred k$ relative to the total cost of putting on the show?

    Its all about cost/benefit. If a case could be made that it would sufficiently benefit the sport, the tech is there to do it. If its cheaper to pay for more spotters and some ground-based tech in place, that would be the way to go. I'm afraid the current thinking is that its plenty affordable to just risk unfairly penalizing a couple of teams per year and say "sorry, but that's just tough." :-/

  5. #15
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    Default Re: Tiger... just wow

    Quote Originally Posted by 440_Magnum View Post
    There are other options, too. Its been a little while since I worked on any of this, but if you have a FIXED reference GPS receiver station (even a relatively cheap one), then the mobile stations can use it as one of their inputs in differential GPS mode- a term that used to be popular for the fixed station was "pseudolite," clever huh? When they're operating in that mode using real satellite data combined with a fixed station, you can get extremely accurate and quick geolocation without any special selective availability codes, so long as you're not too far away from the "pseudolite" station.

    Like I said, its been 10+ years since I helped a co-worker set up a system like that and the whole GPS constellation and processing scheme has been updated at least a little since then, but we were getting centimeter-sized watch-circles out of the mobile stations. The big unknowns for something like Reno would be the possibility of drop-outs at longer ranges from the base station, accuracy degradation due to speed and antenna vibration, and things like that. I would never argue that its a case of "go buy some cheap receivers and throw them in the airplanes," but I honestly think its a whole lot less than the $20k per unit high-end receivers. I could see each complete aircraft data *package* including inertial components and telemetry (or logging for post-processing) package being on the order of $20- $30k, but since they could be standardized and re-issued for each race you would only need enough for the size of a heat plus spares and alternates. How painful is a couple hundred k$ relative to the total cost of putting on the show?

    Its all about cost/benefit. If a case could be made that it would sufficiently benefit the sport, the tech is there to do it. If its cheaper to pay for more spotters and some ground-based tech in place, that would be the way to go. I'm afraid the current thinking is that its plenty affordable to just risk unfairly penalizing a couple of teams per year and say "sorry, but that's just tough." :-/
    Perhaps something like that could work. However, a huge part of the problem is the software filtering in the individual receiver. No matter if it has 12 satellites, it still will not put out a valid solution if the software filtering is in place.

    Michael

  6. #16

    Default Re: Tiger... just wow

    Quote Originally Posted by Mluvara View Post
    Perhaps something like that could work. However, a huge part of the problem is the software filtering in the individual receiver. No matter if it has 12 satellites, it still will not put out a valid solution if the software filtering is in place.

    Michael
    So its a built in software "issue" got it. Thanks I have seen the tracks that you have shared in the past, how accurate are those generally? Are we talking hundreds of feet off or is 5-10 feet off of actual path of travel?

    I see the solution to the deadline cuts as a combination. First multiple observers just like the pylons judges, second fixed camera shooting through a vertical line on the ground, and third on board GPS transmitters. With that a clear written policy that lines out how it will be called. As it has been presented here and other places, a single person can make that call with no appeal process, and can wait 2 hours to notify the contest contestant. I understand the Govt. is involved but thats not a way to run things.

  7. #17
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    Sep 2002
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    Sacramento, CA.
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    739

    Default Re: Tiger... just wow

    I seriously don't think RARA is "sophisticated" enough to use GPS or any other electronic device to determin race results. So I really think the point is moot. They have they're systems in place and that is going to be the way it is. Unfortunatly. This year Thom was DQ'd but he had video evidence clearly showing there was no violation. Was RARA willing to even look at it for a possible change of their decision? Hell no! This is not NASCAR, this is not NFL, There will be no "Challenges" or protests that are even going to be given the time of day. This is an organisation that is set in their ways, and no one is going to change that! As I write this (Tuesday, the 2nd day after the race) I doubt if there's a board meeting going on with RARA, with the questions being asked of "How can we make this better next year", "Hey, there were two questionable DQ's made this year, let's take a second look at those in the name of fairness", "If we advertised a car drop, why didn't that happen, and why didn't we explain that to the fans, and what can we do to change that". I'm positive that right now money is being counted, ticket sales are being totalled, vendor percentages are being calculated, parking fees are being assesed, etc. This was my 34th year at Reno, and I'll still book my vacation for September next year. I'll still get excited in the weeks leading up to the races, I'll still speculate on who is going to win, etc. However, I know that nothing is going to change as far as RARA's treatment of the fans, and their lack of vision for promoting the worlds fastest motorsport. I can't change the channel, because there is no other channel. I don't mean to be so cynical. But after 34 years of yelling "Wake the F up" to deaf ears, I just have to shake my head.

    Just my .02
    Race 29
    Full throttle till you see God, then turn left!

  8. #18
    Join Date
    Feb 2004
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    Portland, Or
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    1,205

    Default Re: Tiger... just wow

    Quote Originally Posted by Race 29 View Post
    I seriously don't think RARA is "sophisticated" enough to use GPS or any other electronic device to determin race results. So I really think the point is moot. They have they're systems in place and that is going to be the way it is. Unfortunatly. This year Thom was DQ'd but he had video evidence clearly showing there was no violation. Was RARA willing to even look at it for a possible change of their decision? Hell no! This is not NASCAR, this is not NFL, There will be no "Challenges" or protests that are even going to be given the time of day. This is an organisation that is set in their ways, and no one is going to change that! As I write this (Tuesday, the 2nd day after the race) I doubt if there's a board meeting going on with RARA, with the questions being asked of "How can we make this better next year", "Hey, there were two questionable DQ's made this year, let's take a second look at those in the name of fairness", "If we advertised a car drop, why didn't that happen, and why didn't we explain that to the fans, and what can we do to change that". I'm positive that right now money is being counted, ticket sales are being totalled, vendor percentages are being calculated, parking fees are being assesed, etc. This was my 34th year at Reno, and I'll still book my vacation for September next year. I'll still get excited in the weeks leading up to the races, I'll still speculate on who is going to win, etc. However, I know that nothing is going to change as far as RARA's treatment of the fans, and their lack of vision for promoting the worlds fastest motorsport. I can't change the channel, because there is no other channel. I don't mean to be so cynical. But after 34 years of yelling "Wake the F up" to deaf ears, I just have to shake my head.

    Just my .02
    Race 29

    Summed up nicely. They dont care. $$$ is the only thing on their minds.

  9. #19

    Default Re: Tiger... just wow

    Quote Originally Posted by Race 29 View Post
    I seriously don't think RARA is "sophisticated" enough to use GPS or any other electronic device to determin race results. So I really think the point is moot. They have they're systems in place and that is going to be the way it is. Unfortunatly. This year Thom was DQ'd but he had video evidence clearly showing there was no violation. Was RARA willing to even look at it for a possible change of their decision? Hell no! This is not NASCAR, this is not NFL, There will be no "Challenges" or protests that are even going to be given the time of day. This is an organisation that is set in their ways, and no one is going to change that! As I write this (Tuesday, the 2nd day after the race) I doubt if there's a board meeting going on with RARA, with the questions being asked of "How can we make this better next year", "Hey, there were two questionable DQ's made this year, let's take a second look at those in the name of fairness", "If we advertised a car drop, why didn't that happen, and why didn't we explain that to the fans, and what can we do to change that". I'm positive that right now money is being counted, ticket sales are being totalled, vendor percentages are being calculated, parking fees are being assesed, etc. This was my 34th year at Reno, and I'll still book my vacation for September next year. I'll still get excited in the weeks leading up to the races, I'll still speculate on who is going to win, etc. However, I know that nothing is going to change as far as RARA's treatment of the fans, and their lack of vision for promoting the worlds fastest motorsport. I can't change the channel, because there is no other channel. I don't mean to be so cynical. But after 34 years of yelling "Wake the F up" to deaf ears, I just have to shake my head.

    Just my .02
    Race 29
    I don't disagree with you one bit. The only thing that is different this time is the Title sponsor of the Gold Race is also the sponsor of a plane that was DQ'd. If I was in that situation I would take a solution to my sponsor and suggest they make that a requirement for RARA getting $$$$ next year. (Whatever that solution is, not necessarily gps transmitters)

  10. #20
    Join Date
    Sep 2011
    Location
    Santa Fe, NM
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    181

    Default Re: Tiger... just wow

    Quote Originally Posted by Arctic Cat View Post
    I don't disagree with you one bit. The only thing that is different this time is the Title sponsor of the Gold Race is also the sponsor of a plane that was DQ'd. If I was in that situation I would take a solution to my sponsor and suggest they make that a requirement for RARA getting $$$$ next year. (Whatever that solution is, not necessarily gps transmitters)
    Breitling execs. after Sunday's Gold race. "Awesome! A podium finish for Precious Metal. Get the advertising guys on the phone right now for a full-page ad in the New York Times congratulating Thom. Uh, what's that? Disqualified? What's a showline cut? Alright, never mind......"

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