Change Detection

Question 1

What are the two types of algorithms for change detection

Answer 1

Pair wise and multi date

Question 2

What are the three single band pair wise techniques

Answer 2

Image differencing, image rationing and regression analysis

Question 3

What are the two multi band pair wise change detection techniques

Answer 3

CVA (determines length and direction vector) and post classification comparisons(classifies separately and compares classes on pixel by pixel basis)

Question 4

What are the types of multi date image change detection techniques

Answer 4

Image deviation, CVA, time sequencing and profiles, principal component analysis

Question 5

What criteria needs to be met in order to directly compare images for change?

Answer 5

Must register exactly, have same spatial resolution and geometry, record data in the same spectral ranges, be taken at the same time of day, have a systematic time interval