PROBABILITY OF DETECTION (POD)

(The probability that the subject or clues will be detected.)

· Search segments should be assigned specific desired POD values.

· Team leaders should be briefed on the specific POD objective for the assignment.

· Team leaders should confer with team members to estimate the actual POD after completing the assignment.

o % POD is the estimate of the number of clues that a resource would be expected to find if 100 clues existed in the segment.

o % POD = 100 – 1/2 spacing (ft)

§ 20 ft spacing = 90% POD

§ 60 ft spacing = 70% POD

§ 100 ft spacing = 50% POD

· POD’s should be calculated once a search assignment has been completed. It is usually better to search an area twice under low-POD conditions than to search it once more thoroughly. Cumulative POD’s for segments searched repeatedly are calculated using the following formula:

% POD_cum = [ 1 - (A x B x C x D x etc.) ] x 100

Where: A = 100% – % POD of first search

B = 100% – % POD of second search

C = 100% – % POD of third search

D = 100% – % POD of fourth search

etc.

example of cumulative POD calculation:

POD of first search = 80% A = 100% – 80% = 20%

POD of second search = 60% B = 100% - 60% = 40%

POD of third search = 50% C = 100% - 50% = 50%

% POD_cum = [ 1 - (20% x 40% x 50%) ] x 100

% POD_cum = [ 1 - .04 ] x 100

% POD_cum = [ 0.96 ] x 100

% POD_cum = 96%