Description
Average two radar reflectivities on a linear scale and return the result in dBZ.
Weather accumulation records need explicit reset, carry, observation-time and area-weight conventions. Trace or missing precipitation differs from measured zero, and radar dBZ must be converted to a linear basis before a linear reflectivity mean. Supplied density, timing and weighting terms do not create a forecast or verify actual weather conditions.
Average two radar reflectivities on a linear scale and return the result in dBZ.
When to use this tool
Use Radar Reflectivity Linear Average Pair when you already have firstDbz, secondDbz and need to average two radar reflectivities on a linear scale and return the result in dBZ.
How to use the tool and how it works
- Enter firstDbz, secondDbz. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read meanDbz. Use the output convention below.
Let high=max(values) and low=min(values); return high+10*log10((1+10^((low-high)/10))/2), avoiding direct exponentiation of the larger reflectivity.1
dBZ expresses a base-10 logarithmic reflectivity ratio with a factor of ten. Averaging the linear ratios before returning to dBZ therefore differs from averaging the two dBZ numbers.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstDbz | First Dbz | Required. Finite number. |
| secondDbz | Second Dbz | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| meanDbz | Equal-weight mean in linear reflectivity followed by logarithmic conversion; not the arithmetic mean of dBZ readings. | Required. Finite number. |
{
"input": {
"firstDbz": 0,
"secondDbz": 10
},
"output": {
"meanDbz": 7.403626894942439
}
}Limitations and assumptions
- This is an equal-weight mean of linear reflectivity, not an arithmetic dBZ mean or a rainfall-rate estimate; no radar measurement or Z-R model is validated.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review the original gauge/radar series, clock and accumulation metadata, including resets and missing intervals. Use the complete spatial or process model for basin precipitation, snow or forecasting; local depth contributions and reference gaps do not infer unobserved weather.
References
Similar or alternative tools
- Radar Gauge Bias Pair
Compare supplied radar and gauge rainfall depths additively and multiplicatively.
- Precipitation Basin Area Weight
Calculate one subarea's precipitation contribution to a supplied basin mean.