Resolution enhancement in the PicoScope oscilloscope software

When capturing high frequency signals you often require the full bandwidth, sampling rate and memory depth of your oscilloscope. For lower frequency applications, however, the maximum sampling rate of the oscilloscope can be hundreds or thousands of times faster than is required to just acquire the signal. Resolution enhancement is a digital filtering technique that uses this ability to oversample in order to increase the effective resolution (improving the ability to see small changes in the waveform) and to reduce unwanted noise.

For this technique to work, the signal must contain a very small amount of Gaussian noise, but for practical applications this is generally provided by the scope itself and the noise inherent in normal signals.

The image shows zoomed detail of a sine wave before and after resolution enhancement to 11.0 bits.

resolution enhancement

Resolution enhancement provides similar results to waveform averaging, but has the advantage that it can be done with single shot-signals (waveform averaging of repetitive signals conversely has the advantage that it can be done at the full bandwidth of the oscilloscope). 

Resolution enhancement is available for all Pico USB PC Oscilloscopes using PicoScope software and can be selected from the Channel Options. It adds up to 4 bits to the effective resolution of a scope. For example, it can boost the effective resolution of a PicoScope 6426E 1 GHz scope from 12 to 16 bits, and the PicoScope 4262 high-resolution scope from 16 bits to 20 effective bits. The resolution enhancement is selectable in increments of 0.5 bit. 

The resolution enhancement feature is a flat moving-average filter. This acts as a low-pass filter with good step response characteristics and a very slow roll-off from the pass band to the stop band.

Note: Resolution enhancement is implemented in software. It is independent of the hardware FlexRes® technology in oscilloscopes such as the PicoScope 4444, 5000D Series and 6000E Series. FlexRes uses a reconfigurable ADC that can be switched between multiple resolutions.