“Service Selection” inputs whose data type is an enumeration of all the alternative specific services available through one service operation. These “Service Selection” inputs could be handled like, or
as an extension of, the Strategy Parameters discussed above.
4.12. Other Inputs and Outputs
Some image exploitation service inputs and outputs do not fall in the above categories. Table 4-2 lists many of these other inputs and outputs, with some information on the possible data format,
mostly using ISO standard IDL data types and structures.
Service Input or Output Possible Data Format
Computed dimensions, including: Distance,
Area, Volume
Angle Time Difference
Velocity NameValueList See Section 4.2, or use:
typedef float Distance; Units: meters typedef float Area;
Units: meters squared typedef float Volume;
Units: meters cubed typedef float Angle; Units: degrees
typedef float TimeDifference; Units: seconds
typedef float Velocity; Units: meters per second
Dimension accuracy estimates typedef float Variance;
Units: Dimension units squared Transformation accuracy estimates
See Position Accuracy Estimates, Section 3.5 Accuracy estimates
See Position Accuracy Estimates, Section 3.5, and: typedef float CE; Units: meters
typedef float LE; Units: meters typedef float SphericalError;
Units: meters
Confidence level for CE and LE typedef float Confidence;
Units: probability Accuracy conversion parameters
NameValueList See Section 3.12.1 Measures of quality of image match
typedef float Confidence; Units: probability
See Position Accuracy Estimates, Section 3.5 Success or failure of metadata
modifications typedef boolean OperationSucceeded;
Table 4-2. Possible Formats of Other Service Inputs and Outputs
Note that all quantities listed as “float” type could alternately be “double” type, if more accuracy is needed. The quantities listed as “float” type are considered unlikely to need more accuracy than
provided by “float”.
4.12.1. Accuracy Conversion Parameters
The “Accuracy conversion parameters” might be formatted as a Name Value List, as discussed below in Section 4.14. For conversion between covariance matrices and CE plus LE, the names and
values shown in Table 4-3 might be used:
Name Data Type
Units Definition Comments
Error Probability float
none Confidence probability for CE and LE error
estimates Note A
Probability Distribution Name
string none
Name of probability distribution, such as “normal distribution”
LE Multiplier float
none Multiplier of standard deviation to obtain LE
with specified probability Note B
CE Multiplier Function
sequence float
none Multipliers of standard deviation to obtain CE
with specified probability Note C
Table 4-3. Possible Accuracy Conversion Parameters
Table Notes:
The Open GIS Abstract Specification Page 49
Volume 15: Image Exploitation Services 00-115 corrigendum
A. The possible probability values include 0.50, 0.6827, 0.90, and 0.95. B. This multiplier is used to compute LE with the specified confidence probability from the
standard deviation of the error square root of the variance. C. These multipliers are used to compute CE with the specified confidence probability from the
standard deviation square root of the variance along the major axis of the error ellipse. The CE is computed from the covariance matrix of the expected errors in two axes, either the two
horizontal ground coordinates or the two image coordinates. When the error estimates in the two axes are correlated andor are not equal, the variances are first computed for the major and minor
axes of the error ellipse. The ratio of the variance in the minor axis to the variance in the major axis of the error ellipse is then computed. As this ratio varies from 0.0 to 1.0, the multiplier needed to
compute CE varies from one number to a larger number.
The multipliers are specified for a variable number of evenly spaced values of the minormajor axis variance ratio, from 0.0 to 1.0. The number of ratio values may be 21, for ratio values differing by
0.05. For a minormajor ratio between the recorded values, linear interpolation is used.
4.13. Other Possible Outputs
