TABLE OF CONTENTS When faced with a number of parameter values measured by various methods in different locations at different times, the analyst must determine the likely range of the parameter involved for a given type of radar. One simple method is to take the largest and smallest observed values as the parametric limits (e.g., the RF range could be from the lowest reported RF value to the highest reported RF value). Unfortunately, this can place too much emphasis on extreme values that may actually represent errors.
One common practice is to report ELINT parameter limits as being those that include 95% of the data values. Selection of the data to be used requires care and judgment on the part of the analyst. It may be useful to eliminate values having a poor accuracy or that are too old. Generally, it is necessary to look at the range determined by the overall set of data values and then compare this to the ranges indicated when various subsets of the data are analyzed. For example, the parameter range indicated by 5 years of data values may be compared to those indicated by data from each year individually to see if changes with time are occurring.
A histogram gives the number of occurrences of a parameter value within a range of values. For example, a table showing the number of people from 0 to 10 years of age, from 10 to 20 years, from 20 to...
