One type of RS technology thats particularly of interest today is ground based weather RADAR. Pulses of microwave energy are broadcast and the intensity, shift and time delay of returned signals arerecorded and in this case interpreted as rainfall, giving intensity and location of rain as it happens.
You can get Irish RADAR data live from the met service. Or to see things in context go to meteox.com for an european wide RADAR feed in real time.
BTW if you are palnning your journey home- meteox provide location specifc forcast in 3hr intervals – Dublin commuters are going to get wet!