S.C. Code Regs. § § 49-440
Current through Register Vol. 48, 12, December 27, 2024
Section 49-440 - Classification of SurveysA. The accuracy of the measurements for a survey shall be based upon the character of the land, the type of survey and the current use of the land. Unadjusted Ratio of Precision permissible shall be no less than the errors of closure prescribed below. In lieu of an Unadjusted Ratio of Precision, a Relative Positional Accuracy may be used. Relative Positional Accuracy may be tested by: (1) comparing the relative location of points in a survey as measured by an independent survey of higher accuracy or (2) the results of a minimally constrained, correctly weighted least square adjustment of the survey.B. On the basis of the size and character of the land, boundary surveys for conveying, platting, mapping, or describing property shall be classified as follows: (1) (Class A) Urban Land Surveys: Urban surveys include land properties which lie within or adjoin city or town limits, or other high valued properties. Bearings shall be shown in degrees, minutes and seconds and distances shall be shown to hundredths of a foot.(2) (Class B) Suburban Land Surveys: Suburban surveys include properties surrounding the urban area of a town or city. Bearings shall be shown in degrees, minutes and seconds and distances shall be shown to hundredths of a foot.(3) (Class C) Rural Land Surveys: Rural surveys include properties located outside suburban properties. Bearings shall be shown in degrees and minutes or less and distances shall be shown to hundredths of a foot.(4) (Class D) Farm and Timber Land Surveys: Timber surveys include properties located throughout the State and represent land which may be cultivated; may provide space for farm houses and buildings; or may be employed as timber land. Bearings shall be shown in degrees and minutes or less and distances to the nearest tenth of a foot or less.(5) (Class E) Vertical Control Surveys: Surveys involving vertical control (leveling) for land areas where a common datum is necessary shall be classified on the basis of accuracy. (a) Urban Control: Control loops employed for commercial, industrial, or urban land surveys shall be executed with a precision or error of closure not to exceed in feet 0.04 times the square root of the number of miles of the level circuit. i.e. 0.04 [Square root of] m (m = number of miles in the level circuit)(b) Other: Other leveling surveys shall be conducted with a precision or error of closure not to exceed in feet 0.10 times the square root of the number of miles of the level circuit. i.e. 0.10 [Square root of] m (m = number of miles in the level circuit). The VRS will achieve this accuracy when using a dual frequency GNSS receiver, PDOP less than 3 in the absence of multipath.C. Table of Classifications: Classification | A | B | C | D |
Urban Surveys | Suburban Surveys | Rural Surveys | Farm & Timber Surveys |
Unadjusted Linear Closure |
Closure (Minimum) | 1:10000 | 1:7500 | 1:5000 | 1:3000 |
Angular Closure (Maximum) | 15" [Square root of] N | 20" [Square root of] N | 30" [Square root of] N | 50" [Square root of] N |
Location of Improvements, Structures, Paving, Etc.: (Tie Measurement) | ±0.1' | ±0.2' | ± 1.0' | ±2.0' |
N = Number of Points in Traverse
As an option:
Relative Positional Accuracy
0.07' + 50 PPM or 0.07' + 1/20,000 * Perimeter (95% confidence level).
The VRS can achieve of a Relative Positional Accuracy of 0.07' with a 95% confidence level and therefore can be used for all Classifications
Amended by State Register Volume 33, Issue No. 6, eff June 26, 2009; State Register Volume 46, Issue No. 05, eff. 5/27/2022.