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    Ground based GPS augmentation systems exist and have been tested.
    However, I haven't heard about anything in our price range.
    Typically in an airport environment, the ground based transmitter is
    broadcasting corrections to the satellite signals rather than an
    imitation satellite signal.<br>
    Standard micro GPS probably wouldn't know what to do with this
    signal. Also the ground-based xmitter is not sized/priced for us. <br>
    However , it may not be necessary to go that route. If we could
    improve on the 3 meter accuracy a bit and the 10hz update rate and
    expand the storage capacity....<br>
    <br>
    But rather than auto-judging, setting up a display showing the plan
    view and vertical view graphically, perhaps with color shading to
    indicate deviation from roll angle = 0 in realtime would be an
    incredible advance in practice/coaching.  Think about it.<br>
    In a square on corner, you would see directly the effect of the top
    corner roll attitude being off 5 degrees and where that took the
    third leg. <br>
    <br>
    John<br>
    <br>
    <div class="moz-cite-prefix">On 5/9/2015 7:07 AM, Daniel Underkofler
      via NSRCA-discussion wrote:<br>
    </div>
    <blockquote
cite="mid:CA+47XXcKSWMBexFuxz5hbk0jPO7yi0kVJYHnECJUR6oEO4+J4w@mail.gmail.com"
      type="cite">
      <div dir="ltr">It's great to see technology like this approaching
        for at least partial automated judging.
        <div><br>
        </div>
        <div>
          <div>Seems that resolving the altitude component adequately is
            the largest challenge.  To address this, I had envisioned a
            local set of 3 "beacons", each emitting GPS-like signals
            that are received and processed by a transponder in the
            model.  Yeah - expensive and even more out in the future.</div>
          <div><br>
          </div>
          <div>In the short term, using high resolution and update GPS
            to resolve XY location might be useful for partial judging. 
            Human judges would still be responsible for the majority of
            the scoring, but a "correction factor" for XY errors might
            be factored in.  For instance, it is terribly hard to judge
            the geometry of the horizontal triangle in F15, but given
            good XY data, a portion of the score could be addressed. 
            Distance and  parallelism to the runway could also be
            determined and factored in (somehow).</div>
          <div><br>
          </div>
          <div>Dan</div>
        </div>
      </div>
      <div class="gmail_extra"><br>
        <div class="gmail_quote">On Fri, May 8, 2015 at 9:33 PM, John
          Gayer via NSRCA-discussion <span dir="ltr"><<a
              moz-do-not-send="true"
              href="mailto:nsrca-discussion@lists.nsrca.org"
              target="_blank">nsrca-discussion@lists.nsrca.org</a>></span>
          wrote:<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div bgcolor="#FFFFFF" text="#3333FF"> The judges are
              expected to consider the track of the plane in an earth
              coordinate system. For example the judges are supposed to
              consider that a 45 degree climb appears steeper at the end
              of the box than it does in the center. So the track should
              be analyzed by the judges in an earth coordinate system
              and the track of the model rather than attitude. <br>
              <br>
              The location of the pilot is actually irrelevant but the
              location of the box is clearly of critical importance.
              Knowing the actual location of the plane with a fairly
              quick update rate is critical. At 120 feet/sec(approx 80
              mph), horizontal position is no problem. At this speed you
              need an update rate of about 80 milliseconds to get a data
              point about every 10 feet. Not sure how good the GPS
              update rates are these days but this should be achievable.
              IF the altitude update rate is too slow then augment with
              an altimeter. Since we are downloading this data from the
              model, roll attitude could be transmitted as well for
              wings level.<br>
              <br>
              We would still need a zero judge for snaps, spins and
              stall turns and to establish when the pilot is lost in a
              maneuver. It might be necessary to have an "advance to the
              next maneuver" switch for that case.<br>
              <br>
              It would actually be a fascinating project to download
              accelerations, roll, yaw and pitch rates for analysis
              while observing snaps visually to see if standards could
              be established about what is a snap and what isn't.<br>
              <br>
              John<br>
              <br>
              <div>On 5/8/2015 1:24 PM, Peter Vogel via NSRCA-discussion
                wrote:<br>
              </div>
              <blockquote type="cite">
                <div dir="ltr">Not by itself.  Judging/Scoring is from
                  the perspective of the pilot + judges, not from the
                  perspective of the plane.  (As opposed to IAC, where
                  it's from the perspective of the pilot in the plane). 
                  For it to be done right you'd need to know the precise
                  location of the plane and the precise location of the
                  pilot, then calculate the geometry of the plane's
                  movements relative to the perspective of the pilot's
                  location.  
                  <div><br>
                  </div>
                  <div>The SoloShot 2 automatic cameraman does close to
                    what we want in tracking the movement of the plane
                    relative to a ground station, but from that you'd
                    still need to calculate geometries, and wings level,
                    etc.</div>
                  <div><br>
                  </div>
                  <div>Peter+</div>
                </div>
                <div class="gmail_extra"><br>
                  <div class="gmail_quote">On Fri, May 8, 2015 at 11:44
                    AM, Keith Hoard via NSRCA-discussion <span
                      dir="ltr"><<a moz-do-not-send="true"
                        href="mailto:nsrca-discussion@lists.nsrca.org"
                        target="_blank">nsrca-discussion@lists.nsrca.org</a>></span>
                    wrote:<br>
                    <blockquote class="gmail_quote" style="margin:0 0 0
                      .8ex;border-left:1px #ccc solid;padding-left:1ex">
                      <div link="#0563C1" vlink="#954F72" lang="EN-US">
                        <div>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt">Cheap, <a
                                moz-do-not-send="true"
                                href="http://goo.gl/mZg6RG"
                                target="_blank">Centimeter accuracy GPS</a>.</span></p>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt"> </span></p>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt">No more
                              complaints about biased judging?</span></p>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt"> </span></p>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt">-Keith Hoard</span></p>
                          <p class="MsoNormal"><span
                              style="font-size:14.0pt"><a
                                moz-do-not-send="true"
                                href="mailto:klhoard@hotmail.com"
                                target="_blank">klhoard@hotmail.com</a></span></p>
                          <p class="MsoNormal"> </p>
                        </div>
                      </div>
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                    </blockquote>
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                  <br clear="all">
                  <span class="HOEnZb"><font color="#888888">
                      <div><br>
                      </div>
                      -- <br>
                      <div>
                        <div dir="ltr">
                          <div>Director, Fixed Wing Flight Training</div>
                          <div>Santa Clara County Model Aircraft Skypark</div>
                          <div>Associate Vice President, Academy of
                            Model Aeronautics District X</div>
                          <img moz-do-not-send="true"
                            src="http://farm8.staticflickr.com/7163/6513778381_5569cc985d_m.jpg"
                            height="154" width="200"><img
                            moz-do-not-send="true"
src="https://googledrive.com/host/0B4LOPeyGAgOJUVJmU1dJMVl6WWc/AcademyModelAeronauticsLogo.png"
                            height="136" width="200"><br>
                        </div>
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                    </font></span></div>
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