A radar is an incredibly sensitive instrument, with a dynamic range of around 200 dB (that's 20 orders of magnitude between the minimum detectable signal and the max transmitted power). For an equivalent in terms of sound, it would be like letting off 23kg of TNT (3 metres away), then listening for an echo as loud as the sound of a mosquito (also at 3 metres away)! Of course you wouldn't be alive to hear it!

While the new radars are generally more powerful (~1000 kW peak transmitted power), the MDS will be similar to current radars. But because the transmit power is greater, returns at the MDS level should be able to be detected at a greater range.

• The sensitivity for a radar is given by the Minimum detectable Signal (MDS)
  
• For most met radars the MDS = -110 dBm (can detect returned powers of 10-11 mW!)
  
• Radars typically have peak transmit power 250 kW (C band) or 500 kW (S band)
  
• New radars are in the order of 850-1000 kW! (+90 dBm)