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Table 2 Horizontal precision estimates of four GPS instruments in three built environment types

From: Development of a wearable global positioning system for place and health research

Urban Park

     

Accuracy Description

GPS ID

N

Satellitesa

HDOPa

PDOPa

CEPa

H95a

H98a

6

1371

10.3

1.00

1.87

1.40

3.30

4.00

14

1398

10.3

1.00

1.83

2.20

4.40

4.90

15

1380

10.4

1.03

1.89

2.30

4.90

6.20

23

1374

10.3

1.06

1.93

2.10

5.00

6.70

Mean ± SDc

1380

10.3 ± 0.0

1.02 ± 0.02

1.88 ± 0.04

2.00 ± 0.35

4.40 ± 0.67

5.45 ± 1.06

Rooftop

6

17284

9.9

1.07

1.89

2.50

5.10

5.90

14

17947

9.4

1.10

1.85

2.20

5.00

5.90

15

17946

9.2

1.09

1.87

2.30

5.20

6.30

23

17944

9.3

1.06

1.82

2.40

5.60

6.60

Mean ± SDc

17780

9.4 ± 0.3

1.08 ± 0.02

1.86 ± 0.03

2.35 ± 0.11

5.23 ± 0.23

6.18 ± 0.29

Urban Canyon – Wall Test

1

762

7.2

1.43

3.53

11.40

48.00

69.10

2

770

7.3

1.40

2.81

20.10

24.60

24.60

6

755

7.7

1.49

2.95

9.50

57.90

78.00

15

774

7.5

1.43

2.96

13.40

34.10

39.10

Mean ± SDb

764

7.3 ± 0.2

1.49 ± 0.04

3.16 ± 0.32

14.04 ± 4.62

43.46 ± 14.73

53.14 ± 25.06

  1. a HDOP = horizontal dilution of position; PDOP = positional dilution of position; CEP = circular error probable (50%) in metres; H95 and H98 = horizontal accuracy distribution at the 95 and 98 percent levels in metres. All are averaged values.
  2. b SD = Standard deviation
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International Journal of Health Geographics

ISSN: 1476-072X