Quality numbers
The following table describes the measurement quality numbers provided in the output data. These numbers indicate the measurement certainty. The quality number is calculated as the standard deviation of multiple readings used to return one distance value. A 0 indicates that the reading was not obtained. Numbers greater than 300 indicate a degree of uncertainty in the measurement. Causes of high numbers include:
- sensor is not perpendicular to the target surface
- target is small and reflects little sound
- target surface is rough or uneven
- target surface is a poor reflector of sound (for example, extremely low-density snow)
| Quality number range | Quality range description |
|---|---|
| 0 | Unable to read distance |
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Good measurement quality numbers |
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Reduced echo signal strength |
| 300 to 600 | High measurement uncertainty |
Although not necessary, quality numbers provide useful information such as surface density in snow monitoring applications. Please note that quality number values may increase during snowfall events consisting of low-density snow.