igarss2011_05072011_ho.ppt
TRANSCRIPT
Hilal Özen1, Nigel Fox2, Uğur Murat Leloğlu1, Irina Behnert2, Andrew Deadman2
1 TUBITAK UZAY, METU Campus, 06531 Ankara, Turkey
(hilal.ozen, leloglu)@uzay.tubitak.gov.tr2 NPL, TW11 0LW Teddington Middlesex, UK
(nigel.fox, irina.behnert, andrew.deadman)@npl.co.uk
THE 2010 TUZ GÖLÜ FIELD THE 2010 TUZ GÖLÜ FIELD CAMPAIGN—AN OVERVIEWCAMPAIGN—AN OVERVIEW
CEOS Land Comparison 2010
• Introduction
• Objectives
• Tuz Gölü Calibration Test Site
• Pre-campaign at Tuz Gölü
• Laboratory measurements at METU
• Logistics at CEOS Land Comparison 2010
• Measurements at Tuz Gölü
• Conclusions
CEOS Land Comparison 2010This study provides an overview of the CEOS international comparison carried out at Tuz Gölü in 13 - 27 August 2010.
The CEOS international comparison, infrastructure, analysis etc was largely funded by ESA with additional support from TUBITAK UZAY (Turkey) and NPL (UK) .
All participants were self-funded.
NPL was responsible for the cross-comparison of instrumentation and reference panels in the laboratory and at the site. Additionally, NPL was responsible for the land protocol for field measurements.
TUBITAK UZAY was responsible for the coordination, local support and logistics.
CEOS Land Comparison 2010
Objectives
1. Cross-comparison of field instrumentation used (radiometer and reference panel)- Traceability through NPL standards
2. Evaluate differences in methods for characterising a site
– Small areas (100 m x 300 m) for high and medium resolution imagers
– Large area (1 km x 1 km) for low resolution imagers
3. Establish traceability of Tuz Gölü calibration site
CEOS Land Comparison 2010
Objectives
4. Development of “best practice” guidance
5. A multi-sensor comparison linked to ground calibration derived from multi-team comparison
6. Identify the minimum and ideal specifications for characterisation/instrumentation for a CEOS “reference standard”
Tuz Gölü Calibration Test SiteLocation: 38 50’N, 33 20’E Central Anatolia, Turkey Elevation: 907 mTotal area: 1964 km²Surface type: Salt lake
Tuz Gölü Calibration Test Site
•Tuz Gölü, the second biggest lake of Turkey. •It is a bright natural target, free of vegetation. •It is extremely saline.
•In summer, up to 95% of water in the lake evaporates and exposes an average of 30-80 cm thick salt crust.
•It is in a sparsely populated region with low aerosol content.
Tuz Gölü Calibration Test Site
The Tuz Gölü test site is temporarily instrumented during field campaigns and maintained by TUBITAK UZAY.
The site is open to access to international scientific teams provided they are accompanied by TUBITAK UZAY researchers.
DMC-UK image (24.08.2008)
CEOS Land Comparison 2010
Schedule:
Ankara
13 August 2010 Kick off meeting
14-15 August 2010 Laboratory measurements
Tuz Gölü
16 August 2010 Moving to site and instrumentation instalition
17 - 25 August 2010 Site measurements
Ankara
26 August 2010 Laboratory measurements
27 August 2010 Final meeting
CEOS Land Comparison 2010Participants1. TUBITAK UZAY (Space Technologies Research Institute of The
Scientific and Technological Research Council of Turkey, Turkey)2. NPL (National Physical Laboratory, United Kingdom) 3. ONERA / CNES (French Aerospace Laboratory/French Space
Agency, France)4. VITO (Flemish Institute for Technological Research, Belgium) 5. GISTDA (Thailand Geo-Informatics and Space Technology
Development Agency, Thailand)6. NASA (National Aeronautics and Space Administration, United
States) 7. KARI (Korean Aerospace Research Institute, South Korea)8. CSIR (South Africa Council for Scientific and Industrial Research,
South Africa) 9. NSMC/CMA (Chinese National Satellite Metrological Centre, China)10. SDSU (South Dakota State University, United States)11. INPE (Brazilian National Institute for Space Research, Brazil)
Pre-Campaign at Tuz Gölü by
TUBITAK UZAY
CEOS LAND COMPARİSON 2010
Pre-Campaign at Tuz Gölü The decision on the location of the measurement and camping areas was based on:– surface homogeneity from Terra Modis satellite images (WIST -
https://wist.echo.nasa.gov)– site survey– ease of access to the measurement site
Pre-Campaign at Tuz Gölü Measurement Site Setup – TUBITAK UZAY
Laboratory Measurements at Middle East Technical
University, Ankara
CEOS LAND COMPARİSON 2010
Logistics at Ankara Optical Laboratory at Physics Department, METU
45°/0° Lamp-panel and detector-panel geometry - 45º illumination angle is the sun zenith angle for approximately 07:00 UTC at Tuz Gölü in Aug 2010.
Laboratory Study at Ankara
1 kW FEL lamp
Reflectance panel
ASD radiometerwith a 5º FOV
Reflectance panel cross-comparison
NPL calibrated PTFE reference panel (spectralon like) manufactured by Gigahertz Optik (Optical Diffuser Material)
Reference panel characterisations
Laboratory Study at Ankara
Panel calibrations will be used to normalize participants site reflectance values.
Participants reflectance panels were compared to the NPL panel under stable illumination conditions.
Transfer Standard Absolute Radiance Source (TSARS)
Radiometer cross-comparison against TSAR - NPL
Laboratory Study at Ankara
TSARS
ASD radiometer
Logistics at CEOS 2010 Land Comparison
CEOS 2010 LAND COMPARİSON
Logistics at Ankara and Tuz Gölü
Logistics at Tuz Gölü
UKDMC-2 image (08:03:00 UTC, 17/08/10)
Location of site 3.5 km from entrance
Logistics at Tuz Gölü
Transportation of the equipments to the measurement site by an all-terrain vehicle with trailer
Transportation to the hotels by air conditioned minibuses
Transportation
Logistics at Tuz GölüCamping Area
Logistics at Tuz Gölü
NN
Measurement Site
Measurements at Tuz Gölü
CEOS 2010 LAND COMPARİSON
Spectral Measurements at Tuz Gölü
8 different teams multiple different measurement strategies
Spectral Measurements at Tuz Gölü17 - 25 August 2010 Site Measurements
1km x 1km site
Spectral Measurements at Tuz GölüAll teams measured the Thome strip – 3 m x 50 m for a rapid short-term comparison study
Spectral Measurements at Tuz Gölü
Comparison study – Measuring NPL’s reference panel with own radiometers
Spectral Measurements at Tuz Gölü
Comparison study - Measuring own reference panel with own radiometers
BRDF Measurements at Tuz GölüNPL performed a BRDF characterization of the site near the measurement sites using the Gonio RAdiometric Spectrometer System (GRASS) instrument.
GRASS has been designed to measure the Earth’s reflected sunlight over half a hemisphere, at 30° degree intervals.
GRASS – NPL
BRDF Measurements at Tuz Gölü
Is the BRDF same under fixed illumination conditions?
NPL measured the BRDF of the site under fixed illumination angle of 45 degrees using a calibrated light source provided by ONERA at night time .
GRASS – NPL
Atmospheric Measurements at Tuz Gölü
AERONET Direct Sun Products
Data Format
Aerosol Optical Depth (AOD)with Precipitable Water and Angstrom Parameter
Level 1.0 Level 1.5 Level 2.0
Total Optical Depth Level 1.0Level 1.5Level 2.0
http://aeronet.gsfc.nasa.gov/new_web/photo_db/Tuz_Golu.html
Sunphotometer – TUBITAK UZAY
CIMEL CE318
Atmospheric Measurements at Tuz Gölü
Yankee Environmental Systems Multifilter Rotating Radiometer (YES MFR) - SDSU
Through the process of shadowing the detector with the band, the instrument is capable of measuring total, and diffuse irradiance at six different wavelengths, and calculating direct irradiance. This provides optical depth measurements for water vapor, aerosols, and ozone.
Meteorological Measurements at Tuz GölüWeather Station – TUBITAK UZAY
Davis Vantage Pro2 Wireless Weather Station:•Temperature•Surface pressure•Humidity•Wind speed and direction•Precipitation•Radiation
ConclusionsCEOS Land Comparison 2010 during 13 - 27 August 2010 consisted of both laboratory studies in Ankara and ground measurements at Tuz Gölü test site with the international participation of 11 different scientific teams.
CEOS 2010 Land Comparison
•Development of “best practice” guidance
Characterisation of the calibration test site
Atmospheric characterisation
Satellite sensor radiometric calibration and/or validation
CEOS 2010 Land Comparison
•Traceability through NPL standards
Calibration of instruments against a Transfer Standard Absolute Radiance Source (TSARS) developed by NPL
Correction of bidirectional effects of the target using GRASS developed by NPL
Calibration of reference panel using a 1 kW FEL lamp and NPL calibrated PTFE reference panel (spectralon like) manufactured by Gigahertz Optik (Optical Diffuser Material)
CEOS 2010 Land Comparison•Cross-comparison of instrumentation
Cross-comparison of radiometers at the site
Cross-comparison of radiometers at the laboratory
Cross-comparison of reference panels at the site
Cross-comparison of reference panels at the laboratory
CEOS 2010 Land Comparison•Cross-comparison of ground measurements made by different teams
FY3A, Beijing1, DEIMOS1, UKDMC2, SPOT 4-5, LANDSAT 5-7, MERIS, ALOS Avnir-2, RAPIDEYE constellation, MODIS, THEOS, Worldview2, EO-1 Hyperion and ALI satellite overpasses
•Cross-comparison of Top-of-Atmosphere measurements made from different satellite sensors
Uncertainty analyses, repeatability, reproducibility.
For more information about Tuz Gölü radiometric calibration test site:1.Cal/Val Portal; http://calvalportal.ceos.org/cvp/web/guest/tuz-golu2.USGS test site catalog; http://calval.cr.usgs.gov/sites_catalog_template.php?site=tuzg3.Hilal Özen, TUBITAK UZAY; [email protected]
at Tuz Gölü