Upsampling question- Aliasing/imaging problem

1. Can upsampling cause aliasing?
2. What is imaging and aliasing?
3. What is the effect of upsampling in the frequency domain?
4. Which performs better downsampling upsampling or leaving the data Raw?

Can upsampling cause aliasing?

It means creation of frequency components above 1/2 sampling rate of the original signal. Sometimes it is also considered to be a form of aliasing. When you are upsampling by a non-integer ratio (e.g. from 44.1 to 96 kHz), you get both imaging above 1/2 sampling rate of the original signal and aliasing below that rate.

What is imaging and aliasing?

Aliasing is when a higher frequency mirrors DOWN about 1/2 the Nyquist frequency, but Imaging is when a lower frequency mirrors UP about 1/2 the Nyquist frequency. It has something to do with the DSP reconstruction of the signal the consequences of "zero padding" and so forth.

What is the effect of upsampling in the frequency domain?

Upsampling adds to the original signal undesired spectral images which are centered on multiples of the original sampling rate. In Frequency domain , Upsampling means the padding of zeros at the last of max frequency components on all sides of the signal.

Which performs better downsampling upsampling or leaving the data Raw?

It depends on the level of certainty you need. If you don't need mathematical certainty and just want a heuristic, downsampling is faster and upsampling is more accurate. If you need to put bounds on the accuracy of your computation: it is possible but I can't help you with that.