Special Science Report

February 27, 2008

Guy de Carufel


Project:
GPS Precision Study


Personnel:
Guy de Carufel


Operations Data Collected:
Philip Cunio acted as navigator to reach predefined waypoints using the
following information generated from a programmed graphic calculator:
1. Bias UTM position
2. Distance traveled
3. Distance to target
4. Current Heading
5. Bearing to target
6. Error in bearing
Also, photographs of waypoint markers (large "W" shaped pattern with
stones) and a map of waypoint routes (without topographic features
shown)

Acting as observer, I took note of all points, time delays and
information given to the navigator using the pre-programmed graphic
calculator, GPS device and audio recorder activated by voice (total of
30 minutes of notes taken).

To improve on the next attempt of this exercise, the waypoint markers
where made larger with more stones. Also the Field Documentation
Methodology (FDM) was used to take a panorama of the area at the
waypoint to demonstrate its effectiveness for visually finding a
location later.


Technical/Equipment Issues:
Difficult to press buttons on graphic calculator. Solution was to use
a pen to press the buttons. A small error was detected early in the
programming and was fixed. It did not impair the data recorded.


Discussion:
It appears that navigation was fairly successful using the bias
position up to the point when we were within the range of the bias
value (20m from target). At that point the bearing given was
unreliable, thus the navigator had to rely on visual searching to find
the waypoint marker ("W" out of stones).

The next step will be to repeat the same exercise with a different
crew member to evaluate repeatability. It is expected that it will be
easier to find the waypoint since the markers are now bigger and a
panorama of the areas will be provided.

If time permits, two more EVA's will be done: first as described, and
the second will be to navigate to the points with the same method but
with no bias added to the position to be used as better reference to
later compare.

Full analysis of gathered data will need to be performed.


Questions for CSO:
none at this point.