Citation
Abstract
A review of phase calibration tone processing is given as it applies to a typical radio reference frame experiment processed with the Block II very long baseline interferometry (VLBI) correlator. Because much of the Block II correlator process- ing is similar to that of the Block 0’s, our discussion largely follows Thomas’s [4] discussion of Block 0 phase calibration processing. The Block II’s 127-level tone model is the most significant change from the Block 0’s tone processing. We discuss the definitions of the quantities in the Block II output file in sufficient detail to al- low the calculation of tone amplitude, phase, and their respective variances. After reviewing the assumptions and approximations made in tone processing, we conclude that the tone amplitude variance is a function of one parameter—the number of bits correlated—to within ±10. This 10 percent uncertainty is due to oversam-pling, finite side-band rejection, clipper bias, and phase model quantization. Each of these effects is examined theoretically and experimentally and is shown to afiect tone amplitude variance by less than 10 percent.
Keywords
Details
- Volume
- 42-134
- Published
- August 15, 1998
- Pages
- 1–22
- File Size
- 386.9 KB