dB scale for the Reflectivity Field
- dB, or log scale is used for the radar reflectivity field since the returned power to the radar can vary over 8 orders of magnitude!!!!
- db= 10 log(x)
- so receiver takes the log of the signal (in base 10)
- for meteorological radars, typical dB units used are:
where Z = radar reflectivity (more on this later)
- the dBZ unit is used extensively and varies over a range from -20 to 70 dBZ
- In the old days, dBZ was turned into VIP (Video Integrator Processor) levels --->
| VIP Level | corresponding dBZ | Precip Intensity | ||
| 1 | less than 30 | light | ||
| 2 | 30-40 | moderate | ||
| 3 | 40-45 | heavy | ||
| 4 | 45-50 | very heavy | ||
| 5 | 50-57 | intense | ||
| 6 | greater than 57 | extreme |
