Measuring Response Time

Response Time measures the time between a request for coverage of a point and the time at which coverage is achieved. The dynamic definition of Response Time is the time until the next access begins; it is defined as 0 if the point is currently in access, and as 1000000 seconds if the animation time is later than the end of the last access period. Options for the static definition of Response Time are described in the following table.

Compute options for Response Time

Option	Description
Average	The average response time over the entire coverage interval. Computed as:
Maximum	The maximum response time over the entire coverage interval. Useful in determining the length of the longest gap between coverages
Minimum	The minimum response time over the entire coverage interval. Value is 0 if any accesses exist for the grid point
Percent Below	The value computed indicates that the point has a Response Time of at most R, X percent of the time, where R is the computed value and X is the Percent Level you specify
Percent Below Gaps Only	The computed value indicates that the point has a response time of at most R, X percent of the time when in a coverage gap, where R is the computed value and X is a Percent Level that you specify.

STK Coverage uses an "optimistic" algorithm when coverage gaps that share a boundary with the coverage interval exist. The span of the coverage gap is measured using the coverage interval bound. This is important for the correct interpretation of the Age Of Data, Revisit Time, Time Average Gap and Response Time figures of merit.

Min # Assets

Use this field to specify the minimum number of Assets required for Coverage.

Displaying Response Time in a Graphics Window

Graphics are used to represent the static and dynamic value of Response Time. Graphics representing the dynamic values are only displayed during animation. If Satisfaction is enabled, the graphics follow the general behavior for satisfaction graphics. If Satisfaction is disabled, the graphics appear as described in the following table:

Static or Animation?	Grid points highlighted if they...
Static	are in a coverage gap at least once during the coverage interval
Animation	are currently in a coverage gap

The Satisfaction Threshold value is the time between a request for coverage of a point and the achievement of that request. The default behavior for this Figure Of Merit corresponds to a Satisfaction setting of Greater Than 0.