Fill in the Blanks in the Parameter Space of Observational Astronomy

In observational astronomy, we essentially measure the location, flux density (at certain frequency and certain time), distance and angular size of the sources. A parameter space of observational astronomy can be constructed with the parameters such as the sample size of sources, frequency (bandwidth and frequency resolution), time (observing length and time resolution), sensitivity, and angular resolution of the telescope. Based on the previous experience, we would always obtain new knowledge of the universe with instruments that fill in the blanks in the parameter space, e.g. telescopes used for better surveys (which enlarge the sample sizes of sources), telescopes with higher sensitivity, angular resolution, frequency resolution or time resolution.