SMOS validation sites: Goulburn & Murrumbidgee Cecilia Azcurra Supervisor: Jeff Walker.

SMOS validation sites:Goulburn & Murrumbidgee

Cecilia Azcurra

Supervisor: Jeff Walker

Background

The SMOS satellite will be the first dedicated to the measurement of soil moisture Will measure soil moisture on a 50 x 50 km scale

Ground-based measurements to be used for calibration and validation of soil moisture derived from SMOS

SMOS validation sites are being identified world-wide Australian validation sites will cover a semi-arid

climate

SMOS validation

There is a discrepancy between the scale of SMOS measurements and that of the ground-based (point) measurements

Heterogeneous land cover is an issue Other issues include urban areas and standing

water Sampling needs to represent the soil

moisture over SMOS-sized pixels How many point measurements are required to

obtain the spatial average?

The study areas

Goulburn catchment

Goulburn catchment study area

Oct-31

Goulburn catchment data

Goulburn catchment dataOct-31

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Oct-31, Station M5

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Hydraprobe (0-5cm) Cumulative Rainfall

Goulburn catchment dataNov-07

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Nov-14

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Nov-21

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Yanco region

Soil moisture from air measurements Over 11 days

12 Monitoring stations

Kyeamba Creek

Soil moisture from air measurements Over 3 days

Regional sampling 14 Monitoring stations

General approach

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PLMR Difference (regional samping) Difference (monitoring stations)

Preliminary results – Goulburn catchment

RMSE (regional) = 0.0275 v/v

RMSE (monitoring stations) = 0.0571 v/v

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PLMR Difference (monitoring stations)

Preliminary results – Yanco region

RMSE = 0.0359 v/v

Next steps

Regional sampling data For Goulburn catchment Re-sampling to determine the number of samples

required to determine the spatial mean Monitoring stations

Identify which stations are representative of the area

Bootstrap sampling - Goulburn catchment

Oct

-31

Nov

-07

Nov

-14

Nov

-21

Preliminary results - Goulburn catchment

Soil moisture measurement type

From air Regional samplingMonitoring stations

(6am to 10am average)

DateSoil

moisture

(% v/v)

Soil moisture

(% v/v)

Error

(% v/v)

Soil moisture

(% v/v)

Error

(% v/v)

31-Oct-0546.23 47.54 1.31 38.20 -8.03

07-Nov-0537.80 36.41 -1.39 32.50 -5.30

14-Nov-0517.84 18.57 0.73 19.33 1.49

21-Nov-0516.12 11.01 -5.11 10.15 -5.97

Preliminary results - Yanco region

Air Monitoring Stations

SM (% v/v) SM (% v/v) Error (% v/v)

31-Oct-06 4.36 5.07 0.71

02-Nov-06 2.76 4.76 2.00

03-Nov-06 16.59 13.26 -3.33

04-Nov-06 11.02 11.60 0.58

05-Nov-06 6.48 9.57 3.09

07-Nov-06 4.18 6.90 2.72

09-Nov-06 3.82 6.23 2.41

13-Nov-06 19.20 23.25 4.05

14-Nov-06 11.33 17.58 6.25

16-Nov-06 10.46 14.38 3.92

18-Nov-06 5.41 11.11 5.70