Arcminutes to meters laboratory with cell phones

Heavy rain the night before, 3.8 centimeters, left the ground sodden. Passing pressure front rain showers led to use of the dining hall sidewalk at 8:00. 

View to the east with passing rain showers. 

Starting location at the dining hall.

This term I opted not to subtract the starting value of 0.516 arcminutes. This meant that the result would not be a direct relationship and a y-intercept would be necessary. The 09 minutes was discarded, but in the 11:00 the 54 minutes would be retained in the table. 

Note that this term the decimal minutes were not set to zero at the start.

This generated a y-intercept. 

In another adjustment the tape measure was used to directly measure ten meter segments. The use of the tape measure proved propitious. At the end of the class I could measure off 0.001 arcminutes using the metric tape measure. This was effective.

Ensalyn with the tablet, Arleen recording data.

Only one student had GPS essentials. The tablet served as s second GPS unit. 

In the 11:00 I saw an opportunity to test out a new route. The dining hall route had shown shirt routes can be viable. The new route would push that limit.

The concept was a due North route from classroom building A to the new health center.

The new walkway is not perfectly north-south, but is close enough on a diagonal.

Denny-Ray was the only student in this section with GPS Essentials. 

The view back to the start from the ten Meyer mark.

The 20 meter mark was on the lawn, 30 meters was under the covered walkway. This post was 38 meters. The tape measure reeled in muddy - paper towels were a must. 

There were only five data points but future terms will be able to extend this route well beyond 38 meters. The building is not yet open, a fence is still around the structure. Note too that the full minutes value was kept, generating a y-intercept. There is perhaps less to explain with this approach. While the approach of subtracting the starting 54.543 value to begin at zero is mathematically elegant and yields a direct relationship, the repeated subtracting of the starting value is confusing for the students. 

The graph was reasonably tightly linear.

The resulting arcminutes to meters conversion of 1914 meters per arcminutes was surprisingly accurate with 1842 meters per arcminute being the expected value. This will be a viable route in the future, although this does not lead naturally to the coverage of the prime meridian.

The -104396 meter y-intercept is the distance back down to North 6°, about 104 kilometers. 

Students were cautioned not to use the auto-regression as that generates values for y and x. The same values, but the point is to use the variables in the table.