yellowduck: "Quack" track log for Nordschleife

Track log for Nordschleife

Now SA is turned off, the vastness of the Nordschleife makes for excellent track logs with quack.

Compared to short circuits like Silverstone or Cadwell Park, the GPS-based Quack works best with data at the scale of the Nordschleife and rally stages.

New! Prototype quack-generated MPEG of all the laps I've logged - me & others, wet & dry, bikes & cars ... and one in a car with a trailer towing two bikes. See if you can guess which one that is :-)
It's clear that some laps were before SA was turned off ...
Click for Quack-generated 3Mb MPEG of Ring laps

Post-SA Tracks, showing position/antenna benefits

Even without SA, there can be substantial differences in track recordings. Giving the antenna a clear view of the sky is most important: using an enhanced antenna gives more benefit. Configuring the receiver to record many track points adds the last drop of accuracy.

The significance of the clear view of the sky is huge, as these screendumps from an early version of quack show: In the first picture column below, the receiver was held at the side window of a car ... in the second column, a Lowe antenna was stuck to the roof of a car.

This shows the huge advantages of a better position for the antenna. I don't know how much the Lowe amplifying antenna is to be credited for the improvement. Finally, the GPS III+ track log settings caused many more points to be recorded than in the tracks above.

Nordschleife, August 2000 GPS III+, Standard Antenna inside car (BMW M3) GPS III+, Lowe Active Antenna on car roof (Subaru Impreza)

The receiver doesn't have a great view of the sky (from the side window of a car around Breidscheid or Bergwerk. Some of the errors in this section are due to the lack of satellite visibility, some are because the receiver was set to store relatively few log points.
Satellite visibility varies - even with the same ground conditions - as the satellites move through their different orbits.

This section further shows the errors possible with different track storage settings. Note the strange error on the left of the picture.
Notice that once the receiver has a good view of the sky (from Eschbach onwards) two laps have good accuracy.

The odd steps in this image appear to be because the receiver was set to store track points relatively infrequently - so by the time the receiver had another look at the position, it was way off course.

Going down the thickly-wooded Fuchsrohre, the receiver loses sight of the sky almost completely. The GPS III+ recovery from this situation isn't exactly graceful!

Tracks when Selective Availability was still on

The fixed size of the SA errors means that the bigger you go, the smaller the significance of the error. Some of these laps had comparatively coarse track log configurations in the GPS-III with a standard antenna, yet at this scale they look pretty good.

You can see from here that any zooming in will show the SA errors though!

Nordschleife

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Nordschleife, August 2000	GPS III+, Standard Antenna inside car (BMW M3)	GPS III+, Lowe Active Antenna on car roof (Subaru Impreza)
The receiver doesn't have a great view of the sky (from the side window of a car around Breidscheid or Bergwerk. Some of the errors in this section are due to the lack of satellite visibility, some are because the receiver was set to store relatively few log points. Satellite visibility varies - even with the same ground conditions - as the satellites move through their different orbits.

This section further shows the errors possible with different track storage settings. Note the strange error on the left of the picture. Notice that once the receiver has a good view of the sky (from Eschbach onwards) two laps have good accuracy.

The odd steps in this image appear to be because the receiver was set to store track points relatively infrequently - so by the time the receiver had another look at the position, it was way off course.

Going down the thickly-wooded Fuchsrohre, the receiver loses sight of the sky almost completely. The GPS III+ recovery from this situation isn't exactly graceful!