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Table 5 Estimated variances with a systematic sample size of n = 100 in trend-less populations with autocorrelation, scaled sizes (N), and scaled expected number of site polygons (n(sT), T = 1, 2, 3). All results are based on 30 realizations of a superpopulation, and all or a maximum of 2000 random selections of all possible samples under a systematic sampling design. The standard deviation \( \left(\hat{\sigma}\right) \) across realizations is indicated \( \left(\pm \hat{\sigma}\right) \). Relative variances with DES fixed at 100 are in parentheses

From: Comparison of estimators of variance for forest inventories with systematic sampling - results from artificial populations

N

Array

d

n (s1)

n (s2)

n (s3)

Variance ×102

DES

SRS

MAT

SDR

DOR

57,600

240 × 240

24

96

12

6

0.73 ± 0.10 (100)

1.00 ± 0.13 (137)

0.73 ± 0.22 (100)

0.79 ± 0.22 (107)

0.76 ± 0.13 (104)

230,400

480 × 480

48

96

12

6

0.69 ± 0.08 (100)

1.00 ± 0.12 (145)

0.74 ± 0.22 (107)

0.79 ± 0.22 (114)

0.76 ± 0.12 (111)

192

24

12

0.70 ± 0.08 (100)

1.00 ± 0.13 (143)

0.76 ± 0.22 (108)

0.81 ± 0.22 (115)

0.78 ± 0.11 (112)

921,600

960 × 960

96

96

12

6

0.73 ± 0.08 (100)

1.00 ± 0.12 (136)

0.76 ± 0.22 (104)

0.80 ± 0.23 (110)

0.78 ± 0.12 (106)

384

48

24

0.71 ± 0.08 (100)

1.00 ± 0.13 (141)

0.81 ± 0.23 (114)

0.87 ± 0.23 (122)

0.83 ± 0.11 (118)