XTCE12 — Need a ParameterProperty for "observability" or "change only threshold"

It does not appear possible for the satellite factory to pass a minimum "observability" for parameters using XTCE. It is possible I am mistaken here and a clarification would be sufficient. This type of property is used when determining if a parameter has changed and damps out potential jitter in the measurements.

Allow for a @changeThreshold on the Float and Integer DataEncodingType(s)

An additional of an optional attribute of @changeThreshold for the Float and Integer encoding elements is proposed.

The schema would be modified using the information below. Only the updated attribute is shown in the context of the type name and complexContent to permit easy update. Other items in the complexContent may be addressed in other issues.

<complexType name="FloatDataEncodingType">
...
<complexContent>
<extension base="xtce:DataEncodingType">
<sequence>
...
</sequence>
...
<attribute name="changeThreshold" type="double" use="optional">
<annotation>
<documentation>A changeThreshold may optionally be specified to inform systems of the minimum change in value that is significant. This is used by some systems to limit the telemetry processing and/or recording requirements. If the value is unspecified or zero, any change is significant.
</documentation>
</annotation>
</attribute>
</extension>
</complexContent>
</complexType>

And in the case of the integer encoding:

<complexType name="IntegerDataEncodingType">
...
<complexContent>
<extension base="xtce:DataEncodingType">
<sequence>
...
</sequence>
...
<attribute name="changeThreshold" type="xtce:NonNegativeLongType" use="optional">
<annotation>
<documentation>A changeThreshold may optionally be specified to inform systems of the minimum change in value that is significant. This is used by some systems to limit the telemetry processing and/or recording requirements, such as for an analog-to-digital converter that dithers in the least significant bit. If the value is unspecified or zero, any change is significant.</documentation>
</annotation>
</attribute>
</extension>
</complexContent>
</complexType>