See background and references here: http://physics.stackexchange.com/questions/286529/is-ligo-able-to-detect-the-memory-effect-of-gravitational-waves
LIGO can detect a passing gravitational wave and derive some properties of the source, including energy and distance. After the passage of the gravitational wave a "Christodoulou memory" effect remains. The effect builds up monotonically over the passage of the gravitational wave and results in a permanent change in the distance between two test masses. The memory effect is one order of magnitude smaller than the peak of the wave, and still below LIGO threshold for the two gravitational wave signals confirmed so far, but can be studied with next-generation detectors and clever data analysis tricks.
I am guessing that, even with better detectors, measuring the memory effect alone after the passage of a gravitational wave wouldn't permit deriving the properties of the source (correct?). But perhaps many observations of many sources with many detectors in different places could permit deriving the properties of the sources? Suppose for example there are, say, three events and three detectors, one on Earth and two in other places in the solar system. Could the analysis of the three memory signals measured by the three detectors permit deriving some properties of the three sources?