In a simple random sample, each individual in the population has an equal probability of being chosen. Additionally, each sample of size n has an equal probability of being the chosen sample. This ...
PROC SURVEYSELECT provides a variety of methods for selecting probability-based random samples. With probability sampling, each unit in the survey population has a known, positive probablity of ...
With systematic sampling you can then select the points to monitor but this can introduce bias. Random sampling eliminates bias by generating the points randomly. Now you need sampling tools.