If you understand the zernike polynomials, you can understand its behaviour.

I calculated zernike moments with only order with out any repetitions. I got the result, I didn't find much importance of this repetition , and more over it is increasing the redundancy.

please clear the role of repetition, where it exactly effects on moments?

Zernike moments are related to Zernike polynomials.

Order of Zernike polynomials are related to the number of concentric circular division and degree of repetition are related to the number of circular sectors.

Dear sir,

If order defines the number of concentric circles, but I got 10 concentric circles  with approximately equal radii except  first circle which is near to center,for order=2, with zero repetitions. 

please help me in this regard.

Dear Sucharitha Gowni

https://en.wikipedia.org/wiki/Zernike_polynomials

Zernike Moments depends on the Zernike Polynomials. In Zernike polynomial m plays an important role in the coefficients and frequency of the polynomial. Repetition and frequency can be used interchangeably. If m=0, there is no frequency. Values of 0, cos(theta) and cos(2*theta) are different.

If you have look at the wikipedia page and the figure on top right, you can see that m=0 has only concentric circles, whereas a nonzero m has different pattern.

Please refer this article as well

http://www.telescope-optics.net/zernike_aberrations.htm

thank you very much sir