By Gary Beaney, Tomasz Stapf, Brian Sheppard Meteorological Service of Canada

Variability of Temperature Variability of Temperature Measurement in the Measurement in the

Canadian Surface Weather Canadian Surface Weather and Reference Climate and Reference Climate

Networks Networks ByBy

Gary Beaney, Tomasz Stapf, Brian Gary Beaney, Tomasz Stapf, Brian SheppardSheppard

Meteorological Service of CanadaMeteorological Service of Canada

Background – Regional ProcurementBackground – Regional Procurement When automation of weather stations began in Canada in the late When automation of weather stations began in Canada in the late

1980’s, there was no specifically designated “climate” network1980’s, there was no specifically designated “climate” network

Had a network of “primary” stations recording various meteorological Had a network of “primary” stations recording various meteorological parametersparameters

Background – Regional ProcurementBackground – Regional Procurement When automation of weather stations began in Canada in the late 1980’s, there When automation of weather stations began in Canada in the late 1980’s, there

was no specifically designated “climate” networkwas no specifically designated “climate” network

Had a network of “primary” stations recording various meteorological parametersHad a network of “primary” stations recording various meteorological parameters

When sensors were procured for this network they were done so by When sensors were procured for this network they were done so by five distinct Environment Canada Regionsfive distinct Environment Canada Regions Pacific & Yukon; Prairie and Northern; Ontario; Quebec; AtlanticPacific & Yukon; Prairie and Northern; Ontario; Quebec; Atlantic

Resulted in a wide variety of instruments throughout the country all Resulted in a wide variety of instruments throughout the country all measuring the same parametermeasuring the same parameter

Many of these “primary” stations today are part of Environment Canada’s Many of these “primary” stations today are part of Environment Canada’s Surface Weather and Climate Networks.Surface Weather and Climate Networks.

National survey was undertaken to catalogue the various sensors National survey was undertaken to catalogue the various sensors being used to measure temperature in what are now considered being used to measure temperature in what are now considered Canada’s Surface Weather and Climate NetworksCanada’s Surface Weather and Climate Networks

Background – Sensors in UseBackground – Sensors in Use

Seven different sensors were found to be the predominant source of Seven different sensors were found to be the predominant source of temperature datatemperature data

Sensor Name Sensor Type

CSI HMP35C Thermistor

CSI HMP45CF Thermistor (44002A)

CSI 44002A Thermistor

CSI HMP45C212 YST Thermilinear Sensor (44212)

CSI 44212 YST Thermilinear Sensor

CSI HMP45C Resistance Platinum Sensor (PRT1000)

CSI PRT1000 Resistance Platinum Sensor

Background – Sensors in UseBackground – Sensors in Use National survey was undertaken to catalogue the various sensors National survey was undertaken to catalogue the various sensors

being used to measure temperature in what are now considered being used to measure temperature in what are now considered Canada’s Surface Weather and Climate NetworksCanada’s Surface Weather and Climate Networks

Seven different sensors were found to be the predominant source of Seven different sensors were found to be the predominant source of temperature datatemperature data

In addition to sensor type, differences were reported with respect to In addition to sensor type, differences were reported with respect to shield type and shield aspirationshield type and shield aspiration

Sensor Name Sensor Type

CSI HMP35C Thermistor ±0.5oC -36oC to +50oC

CSI HMP45CF Thermistor (44002A) ±0.4oC -40oC to 0oC ±0.2oC 0oC to +70oC

CSI 44002A Thermistor ±0.4oC -40oC to 0oC ±0.2oC 0oC to +70oC

CSI HMP45C212 YST Thermilinear Sensor (44212) ±0.09oC -50oC to +50oC

CSI 44212 YST Thermilinear Sensor ±0.09oC -50oC to +50oC

CSI HMP45C Resistance Platinum Sensor (PRT1000) ±0.4oC -40oC to +60oC

CSI PRT1000 Resistance Platinum Sensor ±0.4oC -40oC to +60oC

Accuracy

1)1) CSI 44002ACSI 44002A Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)2)2) CSI 44212CSI 44212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A)3)3) CSI HMP35CCSI HMP35C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)4)4) CSI HMP45CCSI HMP45C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)5)5) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A)6)6) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)7)7) CSI HMP45C212CSI HMP45C212 Gill Screen (G)Gill Screen (G) Aspirated (A)Aspirated (A)8)8) CSI HMP45C212CSI HMP45C212 Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)9)9) CSI HMP45CFCSI HMP45CF Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)10)10) CSI HMP45CFCSI HMP45CF Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA) Non-Aspirated (NA) 11)11) CSI PRT1000CSI PRT1000 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)

Eleven predominant sensor types/configurations were found to be in Eleven predominant sensor types/configurations were found to be in use in the Canadian Surface Weather and Climate Networks:use in the Canadian Surface Weather and Climate Networks:

Background – Sensors in UseBackground – Sensors in Use

Purpose: Purpose:

Is a sensor’s reading of temperature close to the truth?Is a sensor’s reading of temperature close to the truth?

N

ibiai XX

N 1

2)(1 X ai = ith measurement made by one system

X bi = ith simultaneous measurement made by another systemN = number of samples used

Is a sensor model consistent in its ability to measure temperature from one identical sensor to Is a sensor model consistent in its ability to measure temperature from one identical sensor to another?another?

Attempt to quantify the variability of temperature Attempt to quantify the variability of temperature measurement in the Canadian Surface Weather measurement in the Canadian Surface Weather and Climate Networks.and Climate Networks.

Is a sensor model consistent in its ability to measure temperature Is a sensor model consistent in its ability to measure temperature over a range of different temperatures?over a range of different temperatures?

OperationalOperationalComparabiliComparabili

ty ty

==

Data - Establishing a “true” Temperature Data - Establishing a “true” Temperature ReferenceReference

Average of the three taken to represent the “true” temperature in Average of the three taken to represent the “true” temperature in the middle of the trianglethe middle of the triangle

ReferenceSensor

1

ReferenceSensor

2

ReferenceSensor

3

Three reference temperature sensors installed in a triangle formation in Aspirated Three reference temperature sensors installed in a triangle formation in Aspirated Stevenson ScreensStevenson Screens

Reference TemperatureReference Temperature

Used average of three YSI SP20048 sensors as referenceUsed average of three YSI SP20048 sensors as reference

Only instances in which all three reference temperature sensors Only instances in which all three reference temperature sensors agreed to within 0.5agreed to within 0.5ooC were used in the analysisC were used in the analysis

Each sensor was calibrated and associated corrections were appliedEach sensor was calibrated and associated corrections were applied

Purpose: Purpose:


N

ibiai XX

N 1

2)(1

N

ibiai XX

N 1

2)(1

X ai = ith measurement made by one systemX bi = ith simultaneous measurement made by another systemN = number of samples used

X ai = ith measurement made by one systemX bi = ith simultaneous measurement made be an identical systemN = number of samples used





ty ty

FunctionFunctionalal

Precision Precision

==

==

1)1) CSI 44002ACSI 44002A Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)

2)2) CSI 44212CSI 44212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A)

3)3) CSI HMP35CCSI HMP35C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)

4)4) CSI HMP45CCSI HMP45C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)

5)5) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A)

6)6) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)

7)7) CSI HMP45C212CSI HMP45C212 Gill Screen (G)Gill Screen (G) Aspirated (A)Aspirated (A)

8)8) CSI HMP45C212CSI HMP45C212 Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA)

9)9) CSI HMP45CFCSI HMP45CF Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)

10)10) CSI HMP45CFCSI HMP45CF Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA) Non-Aspirated (NA)

11)11) CSI PRT1000CSI PRT1000 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA)

Data - Sensors Under TestData - Sensors Under Test

1)1) CSI 44002ACSI 44002A Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) AA2)2) CSI 44002ACSI 44002A Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) BB3)3) CSI 44212CSI 44212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A) AA4)4) CSI 44212CSI 44212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A) BB5)5) CSI HMP35CCSI HMP35C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) AA6)6) CSI HMP35CCSI HMP35C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) BB7)7) CSI HMP45CCSI HMP45C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) AA8)8) CSI HMP45CCSI HMP45C Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) BB9)9) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A) AA10)10) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Aspirated (A)Aspirated (A) BB11)11) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) AA12)12) CSI HMP45C212CSI HMP45C212 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) BB13)13) CSI HMP45C212CSI HMP45C212 Gill Screen (G)Gill Screen (G) Aspirated (A)Aspirated (A) AA14)14) CSI HMP45C212CSI HMP45C212 Gill Screen (G)Gill Screen (G) Aspirated (A)Aspirated (A) BB15)15) CSI HMP45C212CSI HMP45C212 Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) AA16)16) CSI HMP45C212CSI HMP45C212 Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) BB17)17) CSI HMP45CFCSI HMP45CF Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) AA18)18) CSI HMP45CFCSI HMP45CF Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) BB19)19) CSI HMP45CFCSI HMP45CF Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA) Non-Aspirated (NA) AA20)20) CSI HMP45CFCSI HMP45CF Gill 12-Plate Screen (G12)Gill 12-Plate Screen (G12) Non-Aspirated (NA)Non-Aspirated (NA) BB21)21) CSI PRT1000CSI PRT1000 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) AA22)22) CSI PRT1000CSI PRT1000 Wooden Screen (WS)Wooden Screen (WS) Non-Aspirated (NA)Non-Aspirated (NA) BB


Purpose: Purpose:


N

ibiai XX

N 1

2)(1

N

ibiai XX

N 1

2)(1

X ai = ith measurement made by one systemX bi = ith simultaneous measurement made by another systemN = number of samples used

X ai = ith measurement made by one systemX bi = ith simultaneous measurement made be an identical systemN = number of samples used





ty ty

FunctionFunctionalal

Precision Precision

==

==

Reference temperature ≤ -5Reference temperature ≤ -5ooCC Reference temperature > -5Reference temperature > -5ooC and ≤ 5C and ≤ 5ooCC Reference temperature > 5Reference temperature > 5ooCC

Test data was divided into three categories based on reference temperatureTest data was divided into three categories based on reference temperature

Instruments installed at Environment Canada’s Centre for Instruments installed at Environment Canada’s Centre for Atmospheric Research ExperimentsAtmospheric Research Experiments

Located approximately 70 km NW of Toronto, OntarioLocated approximately 70 km NW of Toronto, Ontario

CARE Test Site JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Mean Daily Minimum Temperature (oC) -12.1 -12.9 -7.0 0.2 5.5 10.7 13.2 12.4 8.5 3.3 -1.3 -9.0

Mean Daily Maximum Temperature (oC) -3.2 -2.3 2.8 11.4 18.4 23.6 26.4 25.4 20.9 14.3 6.7 -0.3

Data - Test SiteData - Test Site


Experiment was run from December, 2002 to June, 2003.Experiment was run from December, 2002 to June, 2003.

Minutely data was collected from all three reference sensors and all Minutely data was collected from all three reference sensors and all 22 sensors under test22 sensors under test

In order to maintain a consistent dataset for analysis, if any sensor In order to maintain a consistent dataset for analysis, if any sensor under test was missing a minutely value, the values for that minute under test was missing a minutely value, the values for that minute were removed for all other sensors under testwere removed for all other sensors under test

ResultsResults

CSI PRT1000 WS NA ACSI HMP45CF WS NA BCSI HMP45CF WS NA ACSI HMP45CF G12 NA BCSI HMP45CF G12 NA ACSI HMP45C212 WS NA ACSI HMP45C212 WS A BCSI HMP45C212 WS A ACSI HMP45C212 G12 NA BCSI HMP45C212 G12 NA ACSI HMP45C212 G A BCSI HMP45C212 G A ACSI HMP45C WS NA BCSI HMP45C WS NA ACSI HMP45C G12 NA BCSI HMP45C G12 NA ACSI HMP35C G12 NA BCSI HMP35C G12 NA ACSI 44212 WS A BCSI 44212 WS A ACSI 44002A WS NA BCSI 44002A WS NA A

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

>-5oC and <=5oC

0.0 0.1 0.2 0.3

>5oC Operational Comparability Scores (oC)

Results – Operational Comparability Scores Results – Operational Comparability Scores ((ooC)C)

≤ -5oC

> -5oC and ≤ 5oC

> 5oC


0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

>-5oC and <=5oC

0.0 0.1 0.2 0.3



≤ -5oC

> -5oC and ≤ 5oC

> 5oC

Best = 0.03Best = 0.03 Best = 0.03 Best = 0.03 Best = 0.07 Best = 0.07

Worst = 0.23Worst = 0.23 Worst = 0.15 Worst = 0.15 Worst = 0.29 Worst = 0.29

Avg. = 0.14Avg. = 0.14 Avg. = 0.11 Avg. = 0.11 Avg. = 0.15 Avg. = 0.15

Range = 0.20Range = 0.20 Range = 0.12Range = 0.12 Range = 0.22 Range = 0.22


0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

>-5oC and <=5oC

0.0 0.1 0.2 0.3



≤ -5oC

> -5oC and ≤ 5oC

> 5oC





0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

5

10

15

20

25

30

35

40

CSI HMP45CF/WS/NA A

0

5

10

15

20

25

30

35

40

CSI HMP45CF/WS/NA A

0

5

10

15

20

25

30

CSI HMP35C/G12/NA A

Sensors with Best Operational Comparability Scores

Sensors with Worst Operational Comparability Scores

≤ -5oC

> -5oC and ≤ 5oC

> 5oC

Results – Results – Percentage Frequency of Differences from Percentage Frequency of Differences from ReferenceReference P

erc

enta

ge F

requency

of

Diff

ere

nce

(%

)

0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

10

20

30

40

50

60

70

80

CSI 44212/WS/A A

0

5

10

15

20

25

30

35

40

CSI HMP45CF/WS/NA A

0

5

10

15

20

25

30

35

40

CSI HMP45CF/WS/NA A

0

5

10

15

20

25

30

CSI HMP35C/G12/NA A

Sensors with Best Operational Comparability Scores

Sensors with Worst Operational Comparability Scores

≤ -5oC

> -5oC and ≤ 5oC

> 5oC

0.05%

0.05%

0.02%

15.79%7.38%

12.43%

Results – Results – Percentage Frequency of Differences from Percentage Frequency of Differences from ReferenceReference P

erc

enta

ge F

requency

of

Diff

ere

nce

(%

)

Diff

eren

ce f

rom

Ave

rage

(o C

)

≤ -5oC

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI 44212/WS/A A CSI HMP45CF/WS/NA A

> -5oC and ≤ 5oC

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time


> 5oC

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI 44212/WS/A A CSI HMP35C/G12/NA A

Sensors with Highest and Lowest Operational Comparability Sensors with Highest and Lowest Operational Comparability ScoresScores

Results – Results – Differences from ReferenceDifferences from Reference

Time series represent hourly differences from the reference Time series represent hourly differences from the reference temperature over the period of test temperature over the period of test

Difference between means = 0.34oC



CSI HMP45CF WS NA

CSI HMP45CF G12 NA

CSI HMP45C212 WS A

CSI HMP45C212 G12 NA

CSI HMP45C212 G A

CSI HMP45C WS NA

CSI HMP45C G12 NA

CSI HMP35C G12 NA

CSI 44212 WS A

CSI 44002A WS NA

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

<=-5oC Functional Precision Scores (Functional Precision Scores (ooC)C)

Results – Functional PrecisionResults – Functional Precision

≤ -5oC

> -5oC and ≤ 5oC

> 5oC

CSI HMP45CF WS NA

CSI HMP45CF G12 NA

CSI HMP45C212 WS A


CSI HMP45C212 G A

CSI HMP45C WS NA

CSI HMP45C G12 NA

CSI HMP35C G12 NA

CSI 44212 WS A

CSI 44002A WS NA

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3







≤ -5oC

> -5oC and ≤ 5oC

> 5oC

CSI HMP45CF WS NA

CSI HMP45CF G12 NA

CSI HMP45C212 WS A


CSI HMP45C212 G A

CSI HMP45C WS NA

CSI HMP45C G12 NA

CSI HMP35C G12 NA

CSI 44212 WS A

CSI 44002A WS NA

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3

<=-5oC

0.0 0.1 0.2 0.3







≤ -5oC

> -5oC and ≤ 5oC

> 5oC

Diff

ere

nce

from

Ave

rage

(o C

)D

iffer

enc

e fr

om A

vera

ge (

o C)

Lowest Functional Precision Score

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

TimeCSI HMP45CF/WS/NA A CSI HMP45CF/WS/NA B


-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI HMP45CF/G12/NA A CSI HMP45CF/G12/NA B


-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

TimeCSI HMP45C212/G12/NA A CSI HMP45C212/G12/NA B

Highest Functional Precison Score

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

TimeCSI HMP35C/G12/NA A CSI HMP35C/G12/NA B


-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI HMP35C/G12/NA A CSI HMP35C/G12/NA B


-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI HMP35C/G12/NA A CSI HMP35C/G12/NA B

Sensors with Highest and Lowest Functional Precision Sensors with Highest and Lowest Functional Precision ScoresScores≤ -

5oC> -5oC and ≤ 5oC

> 5oC

Results – Difference from ReferenceResults – Difference from Reference







ConclusionsConclusions

Wide range of Operational Comparability scores observedWide range of Operational Comparability scores observed

Highest – 0.23Highest – 0.23ooCC Lowest – 0.03Lowest – 0.03ooCC In worst case, over 15% of minutely differences from the In worst case, over 15% of minutely differences from the

reference > 0.5reference > 0.5ooCC

Wide range of Functional Precision scores observedWide range of Functional Precision scores observed

Highest – 0.19Highest – 0.19ooCC Lowest – 0.03Lowest – 0.03ooCC

PRT 1000 WS NA A – best operational comparability score in ≤ -5PRT 1000 WS NA A – best operational comparability score in ≤ -5ooC categoryC category HMP45C212 G A A – best operational comparability score in > -5HMP45C212 G A A – best operational comparability score in > -5ooC and ≤ C and ≤

55ooC categoryC category 44002A WS NA A – best operational comparability score in > 544002A WS NA A – best operational comparability score in > 5ooC categoryC category

Purpose of Study– attempt to quantify the variability of temperature Purpose of Study– attempt to quantify the variability of temperature measurement Canadian Surface Weather and Climate Networksmeasurement Canadian Surface Weather and Climate Networks

Closeness to the “truth”Closeness to the “truth”

Consistency from one identical sensor to anotherConsistency from one identical sensor to another

Temperature DependenceTemperature Dependence

Final Note – Future Instrument ProcurementFinal Note – Future Instrument Procurement In order to avoid such variability in the future, one temperature In order to avoid such variability in the future, one temperature

sensor will be procured by a central body and used at all stations sensor will be procured by a central body and used at all stations throughout Canadathroughout Canada

It has been proposed that the analysis methodology used in this It has been proposed that the analysis methodology used in this study be used to select the best instruments for future procurementsstudy be used to select the best instruments for future procurements

Analysis will be undertaken at three different test sites representing Analysis will be undertaken at three different test sites representing significantly different climatologies significantly different climatologies

Should result in a more uniform measurement of temperature and Should result in a more uniform measurement of temperature and other parameters across Canada.other parameters across Canada.

Questions?Questions?

= -5oC

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time


= -5oC

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time

CSI HMP45CF/WS/NA A CSI HMP45CF/WS/NA B

Worst Operational Comparability Score

Best Functional Precision Score


0.31

0.23

-0.01

-0.02

0.28

-0.02

-0.09

-0.10

-0.01

0.16

-0.07

0.12

0.03

0.18

0.03

0.13

0.11

0.28

0.28

0.34

0.30

0.17

-0.2 -0.1 0.0 0.1 0.2 0.3 0.4

<=-5oC

0.24

0.17

0.02

0.07

0.18

-0.06

-0.08

-0.08

-0.04

0.14

0.00

0.17

0.05

0.17

0.06

0.17

0.13

0.22

0.19

0.23

0.17

0.21

-0.2 -0.1 0.0 0.1 0.2 0.3 0.4

>-5oC and <=5oC

-0.03

-0.10

-0.04

0.07

0.33

0.09

0.10

0.08

0.12

0.27

-0.04

0.09

0.12

0.13

0.00

0.11

0.14

0.02

-0.06

-0.05

-0.12

0.26

-0.2 -0.1 0.0 0.1 0.2 0.3 0.4

>5oC

Results – Difference from Reference Mean Results – Difference from Reference Mean ((ooC)C)

Values represent differences between means of each sensor under test Values represent differences between means of each sensor under test and reference (SUT - Reference)and reference (SUT - Reference)

T-test was used to determine if the observed differences in means were T-test was used to determine if the observed differences in means were significant at the 95% confidence level (all sensors highlighted in red)significant at the 95% confidence level (all sensors highlighted in red)

Difference Between Sensor Under Test and Difference Between Sensor Under Test and Reference (Reference (ooC)C)

≤ -5oC

> -5oC and ≤ 5oC

> 5oC

CSI HMP45CF WS NA

CSI HMP45CF G12 NA

CSI HMP45C212 WS A


CSI HMP45C212 G A

CSI HMP45C WS NA

CSI HMP45C G12 NA

CSI HMP35C G12 NA

CSI 44212 WS A

CSI 44002A WS NA 0.073

0.012

0.299

0.001

0.162

0.187

0.153

0.106

0.002

0.036

0.0 0.1 0.2 0.3

<=-5oC

0.074

0.047

0.239

0.002

0.186

0.167

0.111

0.116

0.032

0.063

0.0 0.1 0.2 0.3

<=-5oC

0.071

0.108

0.240

0.012

0.150

0.128

0.009

0.102

0.083

0.070

0.0 0.1 0.2 0.3

<=-5oC

Results – Difference from Reference Mean Results – Difference from Reference Mean ((ooC)C)

Values represent absolute value of differences between means of identical Values represent absolute value of differences between means of identical sensors in identical configurationssensors in identical configurations

T-test was used to determine if the observed differences in means were T-test was used to determine if the observed differences in means were significant at the 95% confidence level (all sensors highlighted in red)significant at the 95% confidence level (all sensors highlighted in red)

Difference Between Identical Sensors Under Test Difference Between Identical Sensors Under Test ((ooC)C)

≤ -5oC

> -5oC and ≤ 5oC

> 5oC

Documents

By Gary Beaney, Tomasz Stapf, Brian Sheppard Meteorological Service of Canada