In MISR Matrix Target ID Fidelity, what do 'Elements' refer to?

• A. The number of distinct targets observed
• B. 1+ sensors required to quantify fidelity
• C. The age of the sensor data
• D. The estimated distance to target

Answer: (B)

In MISR Matrix Target ID Fidelity, Elements are the sensors that contribute to the fidelity calculation. The idea is that fidelity is assessed by comparing information from one or more MISR sensors (each providing a different viewing angle), so the element count is simply the number of sensors used to quantify fidelity. That’s why the option stating that one or more sensors are required to quantify fidelity best fits the concept: at least one sensor is needed to start measuring fidelity, and more sensors can be included to improve the assessment. The other interpretations—such as the number of targets, the age of data, or distance to target—don’t describe what is being counted when we talk about Elements in this context.