GCP Distribution in the Survey Area

GCP Distribution in the Survey Area

This article will describe the best practices for marking and measuring Ground Control Points based on the area to be measured.

GCP Distribution for elongated areas

Ground control points spreading recommendation in relation to desired topographic mapping scale for elongated projects:

 

Num.

 

Map Scale

2 GCP in both project side in each DL or DW [m]

Accuracies in MSE in

95% [cm]

 

Pixel foot print

[cm]

1

1:250

50.0

± 12

2.5

2

1:500

100.0

± 25

5.0

3

1:1250

250.0

± 30

12.5

4

1:2500

500.0

± 40

25.0

5

1:5000

1000.0

± 80

50.0

6

1:10,000

2000.0

± 120

100.0




GCP Distribution for polygonal areas

Ground control points distribution recommendation in relation to desired topographic mapping scale for polygonal (area) projects:

 

Num.

 

Map Scale

 

1 GCP in each square

DL X DL in [m]

 

Accuracies in MSE in

95% [cm]

 

Pixel foot print

[cm]

1

1:250

50.0

± 12

2.5

2

1:500

100.0

± 25

5.0

3

1:1250

250.0

± 30

12.5

4

1:2500

500.0

± 40

25.0

5

1:5000

1000.0

± 80

50.0

6

1:10,000

2000.0

± 120

100.0


  1. Convex hull polygon consisting of GCP’s must cover the entire ROI circumference.
  2. User must add one control point in each DLxDL.




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