Tables summarizing statistical results from full sky (FSky), night-to-night (N2N) and hemisphere (Hemis) overlap scans are found here.

Sources with SNR > 20, where SNR is computed as 1.0857/sigma_mag, were selected within an overlapping scan pair. The difference in magnitude and position was computed for each matching (within 2") source pair. An average delta [J,H,K] magnitude and average delta RA and DEC were computed for each overlapping scan pair. Histograms were made of these averages. Two populations are shown on each histogram. The BLACK histogram incorporates all overlapping scan pair averages where at least 2 matched sources contributed to the average. The BLUE histogram reflects only the overlapping scan pair averages where at least 100 matched sources contributed to the average.

A mean and standard deviation for each distribution were computed and printed on the histogram. The left most statistical group reflects the distribution where the number of match sources > 1 in the overlap regions. The statistical group on the right reflects the distribution where the number of match sources contibuting to the average >= 100. Table A is a summary of the distribution statistics.

Night-to-night overlap analysis is shown for non-pole scan, pole scans and full set of night-to-night scan pairs (pole plus non-pole).

Summary tables comparing the statistical results from full sky, non-pole and pole is here.

Night-to-Night Pole plus Non-pole

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Night-to-Night Non-pole Scans Only

The following histograms represent night to night overlaps from the non-pole scans only.

Figure 1	Figure 2	Figure 3	Figure 4	Figure 5

Outliers in the non-pole overlap histograms have been identified. One pair of scans has average delta magnitudes greater than .2 in all bands. There are three other scan pairs that have average delta J magnitude between .1 and .15. All of these outlier pairs are expained in here .

The tables below gives the mean and standard deviation from the non-pole only histograms:

Table B: Night-to-Night Statistics for Scan Overlaps - Point Source Final Catalog Non-pole (SNR20)

Average Delta	count > 1		count >= 100
	Mean	Std	Mean	Std
J Mag	-.00018	.025	.000087	.019
H Mag	-.00029	.024	-.00039	.018
K Mag	.0000998	.024	-.00024	.017
Ra(arcsec)	-.0054	.095	-.00478	.047
Dec(arcsec)	-.000488	.101	-.00126	.066

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Night-to-Night Pole Scans Only

Figure 1	Figure 2	Figure 3	Figure 4	Figure 5

The tables below gives the mean and standard deviation from the pole only histograms:

Table C: Night-to-Night Statistics for Scan Overlaps - Point Source Final Catalog Pole Only (SNR20)

Average Delta	count > 1		count >= 100
	Mean	Std	Mean	Std
J Mag	-.0015	.029	.0034	.017
H Mag	-.0015	.037	.0014	.014
K Mag	.00098	.030	.0011	.013
Ra(arcsec)	.020	.174	.0054	.054
Dec(arcsec)	-.019	.150	.0007	.078

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Night-to-Night Table Summary

Night-to-Night Table Summary for Counts >= 100

[Last Updated: 2002 Oct 30; by Sherry Wheelock]