Question

How many GCPs will be required for spatial interpolation of different images using 3rd order polynomial function?
(a.) 6
(b.) 10
(c.) 3
(d.) 4

Answer 1

Answer:

Option B is right answer

Explanation:

Answer 2

Answer:

About 10 'ground control points' (GCP) are required for spatial interpolation of different images using 3rd order polynomial function.

Explanation:

• GCP is the points located at a known location on the earth’s surface that is used for "geo-reference Landsat Level-1 imagery".
• The minimum number of GCP for geo-referencing depends upon its order of transformation referred as 1st, 2nd or 3rd order polynomial transformation.

The general formula for calculating the 'minimum number of GCPs' required with the order of polynomial function is:

• The "minimum number of GCPs" required for spatial interpolation $\frac{(t+1)(t+2)}{2}$, where t is the order of polynomial function.

• So for 3rd order of polynomial function: $\frac{(3+1) 3+2}{2}=10$, so a minimum of 10 GCPs are required.