Unformatted text preview: Errors & Measurements Arithmetic mean: Standard deviation: 1 1 1.645 , , , Error of a series: Error of mean: th Weight of i measurement: Departure of side AB Latitude of side AB ∆ ∆ · sin · cos Compass rule departure and latitude adjustments for side AB: Position misclosure: Ratio misclosure: Allowable angular misclosure: Order of traverse 1st Order nd 2 Order Class I 2nd Order Class II rd 3 Order Class I rd 3 Order Class II √ 1.7" 3" 4.5" 10" 12" (after azimuth adjustment) where : Percentile error: Law of propagation of errors: if · 1.960 error of y is ·√ ⁄√ 1 1 ∑ Weighted average: ∑ ∑ · 1:100,000 1:50,000 1:20,000 1:10,000 1:5,000 Error of weighted average: Conversion Factors / Units 1 mi = 5280 ft = 80 Gunter’s Chains 1 ft = 0.3048 m (International foot) 1 in = 2.54 cm (US Survey foot) 360⁰ = 400 grad 360⁰ = 2π rad 1 rad = 206,264.81˝ Angle Measurements Method of repetitions: Avg. Angle · 360° where int · 360° Traversing A C GENERAL: Law of sines: sin sin sin C a B A c Azimuths: 180° bB + Law of cosines: B 2 · cos b or: ⁄2 cos · 2 · Length of side AB from coordinates: Azimuth of side AB from coordinates: Angle from length of sides of triangle: 0,1,2 sin 2 with: · tan · 180° ...
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- Spring '10
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- Trigraph, 1 ft, 1 MI, Gunter’s Chains
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