Key points are not available for this paper at this time.
The COBE DMR sky maps contain low-level correlated noise. We obtain estimates of the amplitude and pattern of the correlated noise from three techniques: angular averages of the covariance matrix, Monte Carlo simulations of two-point correlation functions, and direct analysis of the DMR maps. The results from the three methods are mutually consistent. The noise covariance matrix of a DMR sky map is diagonal to an accuracy of better than 1\%. For a given sky pixel, the dominant noise covariance occurs with the ring of pixels at an angular separation of 60 ° due to the 60 ° separation of the DMR horns. The mean covariance at 60 ° is 0. 45\% ^+0. 18-₀. ₁₄ of the mean variance. Additionally, the variance in a given pixel is 0. 7\% greater than would be expected from a single beam experiment with the same noise properties. Auto-correlation functions suffer from a 1. 5\; positive bias at 60 ° while cross-correlations have no bias. Published COBE DMR results are not significantly affected by correlated noise. COBE pre-print 94-
Lineweaver et al. (Thu,) studied this question.