Is up-sampling prior to cross-correlation useless?

1. Why is upsampling needed?
2. What is the correct way to perform cross-correlation?
3. Is upsampling an interpolation?
4. What happens in upsampling?

Why is upsampling needed?

The purpose of Upsampling is to manipulate a signal in order to artificially increase the sampling rate. This is done by... Upsampling is an effective way to reduce time between samples of a signal without resampling the original signal.

What is the correct way to perform cross-correlation?

Formula for Cross-Correlation

If independent variable X influences variable Y and the two are positively correlated, then as the value of X rises so will the value of Y. If the same is true of the relationship between X and Z, then as the value of X rises, so will the value of Z.

Is upsampling an interpolation?

In digital signal processing, upsampling, expansion, and interpolation are terms associated with the process of resampling in a multi-rate digital signal processing system. Upsampling can be synonymous with expansion, or it can describe an entire process of expansion and filtering (interpolation).

What happens in upsampling?

Upsampling is the process of inserting zero-valued samples between original samples to increase the sampling rate. (This is sometimes called “zero-stuffing”.) This kind of upsampling adds undesired spectral images to the original signal, which are centered on multiples of the original sampling rate.