Angle Analysis Lab Report

980 Words4 Pages
The table shows me that Image E gives a very accurate value, correct to the nearest thirty seconds and meaning my precision in calculating angles has achieved an average (mean) between 0.1 and 0.2 degrees from the true value. The range (difference between small and largest values) is also less that 5% of the average result, suggesting that my angle calculations with different star trails produced repeatable results.

However, Image D is at the complete opposite end of the spectrum, giving a value wildly out by over 14 hours when minute precision is required. This margin of difference is so large that it cannot possibly be caused by measurement errors of the angles, as using the known value for the sidereal day, if the angle were 9.8 degrees
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Using the known value for the sidereal day, if the angle were 9.59 degrees I’d expect an exposure time of around 38 minutes and 24 seconds, which is only five minutes off the recorded time. I’d also expect to have an angle of about 11 degrees with the recorded exposure time. This image produced the least repeatable angle measurement of the three I used, with a range of over 1 degree and over 10% of the mean value. For this reason, it is harder to judge whether the deviance from the correct sidereal day value is down to errors in angle measurement, stacking, calculating/recording exposure times or other errors, although it seems more unlikely to be an error in angle calculation, as 11 degrees is still too large, even with a larger range of…show more content…
Therefore, it is possible that using interval timer photography for all of the images would produce a more accurate result, as human error is largely removed as a problem in the timing stage, although issues are still possible when setting up the equipment. Moreover, this improvement is also only based on three images, a small sample size and an unfortunately anecdotal suggestion. However, it would be an extension to see if a repeat of the observation produced the greatest accuracy with interval timer photography images a second time round, which would suggest that the most accurate result can be achieved with this
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