This document analyzes the quality metadata from 97,203 records harvested from the GEOSS clearinghouse. It finds that 19.66% of records contain quality indicators, with the most common being positional accuracy (37.19%) and completeness (35.71%). Lineage is described in 9.53% of records. The analysis demonstrates that while documentation of quality indicators and lineage is still limited, the current status is sufficient to start developing tools to exploit quality information in catalogs.

1. GEOSS Clearinghouse Qu
Joan Masó1, Paula Díaz1, Miquel Nin
1 Centrefor EcologicalResearchand ForestryApplic
2 UniversitatAutònomadeBarcelona, Spain, email: {
GEOSS – Clearinghouse
GEOSS is investing important efforts in promoting the acknowledgment of the
data quality in Earth observation. GeoViQua project, besides others, has the aim
to make data quality available and visible in GEOSS. The clearinghouse is one of
The number of metada
to make data quality available and visible in GEOSS. The clearinghouse is one of
the main components of the GEOSS Common Infrastructure (GCI), cataloguing
resources.
We developed an exhaustive study of the data quality elements available on the
metadata catalogue in GEOSS clearinghouse, to elaborate a state‐of‐the‐art
0..*
+dataQualityInfo
summary on data quality. This will allow start building components for the GEO
Portal, such as the Quality Broker. The metadata (ISO 19115 compliant) is
harvested and a big database is generated that can be further analyzed.
Detailed results
+ report
0..*
+lineag
0..1
The results reveal that 19.66% of metadata records contain qualityindicators;
(a total number of 52187 quality indicators).
• Diversityof quality indicators used.
o Main representation of the positional accuracy: 37.19%
o Completeness: 35.71%
A
Generic Quality Indicatorsp
o Consistency: 19.78%
o Temporal accuracy: 6.81%
• Lineage described in metadata records:
o Processes: 9.53%
o Sources in 3.88%
Completeness
35.71%
Positional
Accuracy
Thematic Accuracy
0.50%
Temporal Accuracy
6.81%
Q y
The two main metadata
h l d (
o Processes + the sources involved on each process in 1.26%
• Usage is described in 1.17% of the records
These results demonstrate that the documentation of quality indicators and
lineage is far from general in the Earth observation data but current status
Consistency
19.78%
37.20%
Thisproject is funded by the EC 7 Fram
The quality indicators (DQ
(MD_Usage).-This diagram is b
lineage is far from general in the Earth observation data, but current status
is enough to start developing tools to exploit the quality in catalogues.
uality Metadata Analysis
nyerola2, Eva Sevillano2, Xavier Pons2
cations,Spain, email: {joan.maso, paula.diaz}@uab.cat
{miquel.ninyerola,eva.sevillano, xavier.pons}@uab.cat
Detailed Quality analysis on ISO 19115 metadata records
ata records harvested was 97203(October 2011). +processStep
0..*
DESCRIPTION 85%
CITATION 36%
DESCRIPTION 32%
TEMPORAL ELEMENT (EXTENT) 21%
SCALE DENOMINATOR 11%
VERTICAL ELEMENT (EXTENT) 0%
GEOGRAPHICAL ELEMENT(EXTENT) 0%
Source
Elements
0..*
+source
+sourceStep
0..*
PROCESS RESPOSIBLE 12%
DATE AND TIME 3%
RATIONALE 0%
Metadata with process elements 9261
Process
Elements
GEOGRAPHICAL ELEMENT (EXTENT) 0%
Metadata with source elements 5851
ge
+source
0..*
CITATION 100%
DESCRIPTION 0
SCALE DENOMINATOR 0
SOURCE EXTENT 0
Metadata with process elements 1.26%
Process
Elements
+ Sources
Relative Internal
NonQuantitative
Attribute Accuracy
0.00%
Quantitative
Attribute Accuracy
0.50%
Accuracy Of A
Time
Measurement
5.50%
Temporal
Consistency
1 31%
Specific Quality Indicators (subclasse in ISO 19115)
+ result
0..2
meters
3782
16.98%
Quantitative measure units
Coverage
5
0.02%
Quantitative
22275
85.83%
Conformance
3671
14.15%
Result typeCompleteness
Commission
18.81%
Completeness
Omission
16.91%
Topological
Absolute External
Positional
Accuracy
34.04%
Gridded Data
Positional
Accuracy
2.61%
Positional
Accuracy
0.54%
1.31%
nodes studied are directly related with data quality information package (DQ_DataQuality) in ISO:
l ) d h l f ( ) l d d h f
percentage
1168
5.24%
(empty)
17325
77.78%
Conceptual
Consistency
18.12%
Domain
Consistency
1.64%
Topological
Consistency
0.02%
mework Programme, contract no. 265178.
Q_Element) and the lineage information (LI_Lineage). We also considered the usage information
based on ISO 19115 UML schemas,substitutingthe attributes of each elementby the correspondingfor charts with GEOSSquality results.-