As a basic concept, the 2-step process you are referring is valid: first collecting the sensor image/data, then determining notable items/pixels within the collected image that would match some type of pre-established identification criteria. Although this process sounds straight forward, in practicality the process will be a little more involved and may require more than just 2 steps. The data collection and identification are 2 separate processes; one a hardware collection process, the other a software process that identifies the infestation.
The collection is simply recording data from the sensor, but many different items should be taken into consideration during the identification process like: sensor type & resolution, altitude & speed of the flight, size of what you are trying to detect, and environmental factors. During the software identification process the amount of pixels needed to detect infestation will vary depending on factors such as the type of sensor you use and the altitude you fly, etc. This identification process could very easily be a multi-step process on its own.
The State Challenge requires you to cover the entire Area of Interest (AOI) which is 1 square mile. Your team will have to determine the most optimized way to accomplish this coverage requirement. Then based on your coverage technique, determine what steps will be needs to identify the infestation. So the number of pixels required to see an infestation and the amount of time for each step would be determined by your specific operational factors.
