Connecticut Administrative Code › Title 20 - Professional and Occupational Licensing, Certification › 300b - Minimum Standards of Accuracy, Content and Certification for Surveys and Maps › Article II - Classes of Accuracy › Section 20-300b-11 - Classes of accuracy

Current through July 10, 2024
(a) Conversion to
				and from the metric system shall use the U.S. Survey Foot, which is defined as
				one meter is equal to 39.37 inches. When converting meters to feet the
				conversion is exactly 3937 divided by 1200, which when expressed to twelve
				places is 3.280833333333.
(b)
Horizontal Accuracy
Each survey depicting horizontal locations shall conform to a
				  Horizontal Accuracy Class the tolerance of which is defined as follows:
Class
Positional
Feet
Meters
Linear
(Use the ratio for D>...)
Angular
AA
1:15,000
±0.01'
±.003m
(1:22,500 @D>225'(69m))
±8"
A-1
1:10,000
±0.01'
±.003m
(1:15,000 @D>150'(46m))
±10"
A-2
1:5,000
±0.02'
±.006m
(1:7,500 @D>150'(46m))
±20"
B
1:1,000
±0.5'
±.15m
(1:1,500 @D>750'(229m))
±2'
C
±2'
±2'
±.6m
±30'
D
compilation of existing data-NOT A FIELD
								SURVEY
Linear accuracies expressed as "±"apply to distances
				  less than (<) those prescribed as a ratio. Additional accuracy standards for
				  measurements made using Global Navigation Satellite Systems (GNSS) have
				  relative positional accuracy of a ninety five percent level, and are defined
				  as:
Confidence Level
Class
Accuracy
Minimum Spacing
Feet
Meters
G-A
0.033' + 1 PPM
1.0 cm + 1 PPM
500'
G-1
0.049' + 2 PPM
1.5 cm + 2 PPM
500'
G-2
0.067' + 3 PPM
2.0 cm + 3 PPM
335'
G-B
0.33' + 10 PPM
0.10 m + 10 PPM
N/A
(c)
Vertical Accuracy
Each survey depicting vertical location shall conform to a
				  Vertical Accuracy Class the tolerance of which is defined as follows:
Level Loop Closure Greater Than One
								Mile
Class
Feet
Meters
V-1
±.02[RADICAL]M
±.005[RADICAL]M
V-2
±.035[RADICAL]M
±.008[RADICAL]M
V-3
±.05[RADICAL]M
±.012[RADICAL]M
Level Loop Closure Less Than One
								Mile
Feet
Meters
±.006[RADICAL]N
±.002[RADICAL]N
±.010[RADICAL]N
±.003[RADICAL]N
±.020[RADICAL]N
±.006[RADICAL]N
Class V-4* has a GNSS Vertical Accuracy (95% confidence level
				  in feet) of 0.066 feet.
Class V-5* has a GNSS Vertical Accuracy (95% confidence level
				  in feet) of 0.164 feet.
M or K = The length of the level loop in
				  miles/kilometers
N = The number of instrument setups in the level loop
* GNSS only. The surveyor expresses his or her opinion that
				  the differences between heights resulting from repeat observations would not
				  exceed the stated accuracy levels.
(d)
Topographic Survey Accuracy
Each Topographic Survey shall conform to a Topographic
				  Accuracy Class, the tolerance of which is defined as follows:
Class
Horizontal Position
Contour Interval Test
Feet
Meters
T-1
1/40of
								map scale
1/1500of
								map scale
90% within 1/2 contour interval
T-2
1/40
								of map scale
1/1500
								of map scale
80% within 1/2 contour interval
Meters
T-3 This class of topographic map applies to photogrammetric
				  maps for which the surveyor provides the horizontal and vertical control. Refer
				  to the "National Map Standards for Photogrammetric Mapping" for
				  requirements.
T-D This class of map standard applies to topographic maps
				  compiled from various sources of information not necessarily verified by the
				  surveyor.
In using Topographic Accuracy Class T-1 or T-2, the surveyor
				  is expressing confidence that should a test profile be run in the field, a
				  plotted comparison with a profile scaled from the map shall be in agreement
				  within the above criteria and the remainder shall be within the contour
				  interval.