gio global land component - lot i · spot/vgt map. values on proba-v map are lower, down to -3, in...

GIO-GL Lot 1, GMES Initial Operations

Date Issued: 02.10.2014

Issue: I2.00

Gio Global Land Component - Lot I

”Operation of the Global Land Component” Framework Service Contract N° 388533 (JRC)

QUALITY ASSESSMENT NOTE

PROBA-V LAI, FAPAR, FCOVER VERSION 1 (GEOV1)

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Authors: Roselyne Lacaze

Contributing Authors: Fernando Camacho

Bruno Smets



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Document-No. QA Note on PROBA-V LAI, FAPAR, FCover V1 © GIO-GL Lot1 consortium

Issue: I2.00 Date: 02.10.2014 Page: 2 of 15

Dissemination Level PU Public X

PP Restricted to other programme participants (including the Commission Services)

RE Restricted to a group specified by the consortium (including the Commission Services)

CO Confidential, only for members of the consortium (including the Commission Services)



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Change Record

Issue/Rev Date Page(s) Description of Change Release

11.06.2014 All First issue: analysis performed on 4 months of

overlap with SPOT/VGT I1.00

I1.00 02.10.2014 All Second issue: analysis performed on EU

summer 2014 dekads I2.00



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TABLE OF CONTENTS

1 Background of the document ............................................................................................... 7

1.1 Context ................................................................................................................................... 7

1.2 Scope and Objectives............................................................................................................... 7

1.3 Content of the document......................................................................................................... 7

1.4 Related documents ................................................................................................................. 8

1.4.1 Applicable documents .................................................................................................................................. 8

1.4.2 Input .............................................................................................................................................................. 8

2 Analysis ............................................................................................................................... 9

3 Results .............................................................................................................................. 10

4 Conclusions and Recommendations ................................................................................... 15



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List of Figures

Figure 1: SPOT/VGT LAI for 24 August 2013 (Top left) and PROBA-V LAI for 24 August 2014 (top

right), and the difference (SPOT/VGT – PROBAV) (bottom). No clouds are detected over

PROBA-V products while usual cloudy areas (Amazonia, Congo Basin, South East Asia)

appear on SPOT/VGT map. Values on PROBA-V map are lower, down to -3, in the main

vegetated areas of the world (East of USA, Europe and Russia, Eastern Asia, Central Africa,

Indonesia). ............................................................................................................................. 11

Figure 2: LAI transect across Central Africa, from PROBA-V (white line) and SPOT/VGT (orange

line). The 255 values of SPOT/VGT product indicate “no data” due to clouds. The PROBA-V

profile is much noisier, probably due to strong cloud contamination, and the values are three

times lower............................................................................................................................. 11

Figure 3: Temporal evolution of LAI from end of May to end of August. ........................................ 12

Figure 4: Temporal evolution, from end of May to end of August, of the difference between

SPOT/VGT and PROBA-V FAPAR. ....................................................................................... 13

Figure 5: Temporal evolution, from end of May to end of August, of the difference between

SPOT/VGT and PROBA-V FCover. ....................................................................................... 14



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List of Tables



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1 BACKGROUND OF THE DOCUMENT

1.1 CONTEXT

The GEOV1 PROBA-V products are the LAI, FAPAR, and FCover generated from the PROBA-

V 1km data which are first converted into SPOT/VGT-like data using a preprocessing module

[GIOGL1_ATBD_PROBA2VGT] and then ingested into the GEOV1 processing chain.

The PROBA-V GEOV1 products generated from November 2013 to May 2014 have been

compared with the SPOT/VGT GEOV1 products produced during the same period. The results of

this preliminary quality assessment showed realistic values of variables, consistent with

SPOT/VGT estimates, but an excessive number of gaps due to an over-detection of clouds

[GIOGL1_QANote_PROBAV-GEOV1_I1.00]. Following these outcome, it has been decided to

produce, after having disabled a cloud detection criterion into the processing chain, and to

disseminate the PROBA-V products from June 2014 to avoid any disruption in the GEOV1

production. Note that, due to an error configuration of the processing line, the 3 dekadss of June

were produced with both PROBA-V and the last SPOT/VGT data.

The usual quality monitoring performed per variable and across variables on the Jan-Jun 2014

products raised a warning about the quality of the PROBA-V GEOV1 products of June 2014: an

unexpected decrease of the LAI, FAPAR and FCover values has been noted comparing to May

2014. However, a longer time period was needed to confirm this trend.

1.2 SCOPE AND OBJECTIVES

The scope of this note is to present the results of the quality check carried out on the PROBA-V

GEOV1 products generated in (European) summer 2014, and recommend some mitigation

measures based on these results.

1.3 CONTENT OF THE DOCUMENT

This document is structured as follows:

Chapter 2 explains briefly the analysis

Chapter 3 describes the results

Chapter 4 presents the conclusions and the recommendations



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1.4 RELATED DOCUMENTS

1.4.1 Applicable documents

AD1: Annex II – Tender Specifications to Contract Notice 2012/S 129-213277 of 7th July 2012

AD2: Appendix 1 – Product and Service Detailed Technical requirements to Annex II to Contract

Notice 2012/S 129-213277 of 7th July 2012

1.4.2 Input

Document ID Descriptor

GIOGL1_ATBD_PROBA2VGT Algorithm Theoretical Basis Document of the pre-

processing module1

GIOGL1_QANote_PROBAV-

GEOV1_I1.00

Note presenting the results of the preliminary quality

assessment of PROBA-V GEOV1 products2

1 http://land.copernicus.eu/global/sites/default/files/products/GIOGL1_ATBD_PROBA2VGT_I1.00.pdf

2 http://land.copernicus.eu/global/sites/default/files/products/GIOGL1-QANote-PROBAV_GEOV1-I1.00.pdf



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2 ANALYSIS

Once available, the July and August PROBA-V GEOV1 products were analysed. They have been

compared with SPOT/VGT products generated during the (European) summer of 2013, regarding

the spatial and temporal patterns, variations and absolute values of variables.



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3 RESULTS

It appears clearly that:

No more clouds are detected: there are no gaps in the products, even over equatorial areas

known for their usual cloud coverage (Figure 1)

Values of LAI are too low, comparing to the SPOT/VGT LAI of summer 2013 (Figure 1,

Figure 2).

The temporal variations are unrealistic, as the African tropical rainforest “disappears” from

May to August (Figure 3)

Differences are also noted on FAPAR with general lower PROBA-V values (down to -0.4)

over all vegetated areas of the globe (Figure 4).

The same trend is observed on the FCover (Figure 5)



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Figure 1: SPOT/VGT LAI for 24 August 2013 (Top left) and PROBA-V LAI for 24 August 2014 (top

right), and the difference (SPOT/VGT – PROBAV) (bottom). No clouds are detected over PROBA-V

products while usual cloudy areas (Amazonia, Congo Basin, South East Asia) appear on

SPOT/VGT map. Values on PROBA-V map are lower, down to -3, in the main vegetated areas of

the world (East of USA, Europe and Russia, Eastern Asia, Central Africa, Indonesia).

Figure 2: LAI transect across Central Africa, from PROBA-V (white line) and SPOT/VGT (orange line).

The 255 values of SPOT/VGT product indicate “no data” due to clouds. The PROBA-V profile is much

noisier, probably due to strong cloud contamination, and the values are three times lower.



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Figure 3: Temporal evolution of LAI from end of May to end of August.



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Figure 4: Temporal evolution, from end of May to end of August, of the difference between SPOT/VGT

and PROBA-V FAPAR.



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Figure 5: Temporal evolution, from end of May to end of August, of the difference between SPOT/VGT

and PROBA-V FCover.



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4 CONCLUSIONS AND RECOMMENDATIONS

This quality control showed that the PROBA-V GEOV1 (Version 1.3) products do not reach the

required level of quality necessary to be disseminated and to be used with confidence.

Consequently, the PROBA-V GEOV1 production in Near Real Time has been stopped and the

available products (24 May 2014 till today) were made unavailable on the product access web

portal.

Further, it is recommended to not use the PROBA-V LAI, FAPAR, FCover Version 1.3 for any type

of application.

Actions are in progress to identify the cause of the problem and to correct it, in order to allow

production of PROBA-V GEOV1 to resume as soon as possible. Once the production is resumed,

the available dataset (from 24 May 2014) will be re-processed to Version 1.4.

gio global land component - lot i · spot/vgt map. values on proba-v map are lower, down to -3, in...

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