MODIS Land Science

Products Production

MODIS Land Science

Products Production

Robert E. WolfeNASA Goddard Space Flight Center, Code 614.5

Greenbelt, MD, USA

This work was performed in the Terrestrial Information

Systems Branch (Code 614.5) at NASA’s Goddard Space

Flight Center Laboratory for Terrestrial Physics.

Acknowledgement

11

1212

MODIS on EOS Terra and AquaMODIS on EOS Terra and Aqua The MODerate Resolution Imaging

Spectroradiometer (MODIS), a key instrument for NASA’s Earth Observing System (EOS)

MODIS was launched on board the Terra spacecraft in Dec. 1999 (first light on Feb. 24, 2000) and on board the Aqua spacecraft in May 2002 (first light on June 24, 2002)

Spatial resolution at nadir: 250m (2 bands), 500m (5 bands) and 1000m

12 bit (0-4095) dynamic range

MODIS Land ProductsMODIS Land ProductsEnergy Balance Product Suite Surface Reflectance Land Surface Temperature and Emmisivity Bi-directional Reflectance Distribution

Function (BRDF) and Albedo Snow cover and sea-ice extent

Vegetation Parameters Suite Vegetation Indices Leaf area index and Fraction (LAI) and Fraction

of Photosynthetically Active Radiation (FPAR) Gross and Net Primary Production (GPP/NPP)

Land Cover/Land Use Suite Land Cover/Vegetation Dynamics Vegetation Continuous Fields Vegetation Cover Change Fire/Thermal Anomalies and Burned Area

33

1111 Getting MODIS Land DataGetting MODIS Land Data

22 Land Science Team – Phase 2Land Science Team – Phase 2 Overall – Phase 1 Land Team intact and strengthened

Separate funding for Validation Coordination and Rapid Response

Larger Science Team (27 total) Algorithm Maintenance and Validation Team (10) EOS Science – Data Users (17) Four new/improved Land products: Plant Water

Content, Evaporation, Improved Surface Reflectance, Physical Based Continuous Fields and Land Cover

Land Discipline Leader: Dr. Chris Justice, UMD

44 MODIS CollectionsMODIS Collections

Each collection represents an improvement in science qualityEach collection represents an

improvement in science quality

77 MODIS Product FormatMODIS Product Format Hierarchical Data Format (HDF) – self describing file

format Science Data Sets (SDSs) – 2D, 3D or 4D arrays

Bit Fields – unsigned integers broken into groups of bits

Discrete values – e.g., Snow, Cloud, etc. Scaled Integers – valid range, scale and offset included

Attributes – text or other data annotating the file (global) or arrays (SDSs)

Metadata – ECS product metadata (stored as attributes) includes QA information, date/time products

acquired/produced, etc. .met file contains the ECS core metadata: some fields

(QA, etc.) may be updated when product distributed HDF-EOS Metadata (SWATH or GRID) – geometric

information that relates data to specific earth locations

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Retrieved geophysical parameters at same location and in same format as MODIS Level 1 instrument data 288 granules/day; 5 min.;

approx. 2340 x 2030 km 250m, 500m and 1km

nadir resolutions

Level 2 SwathLevel 2 Swath Level 2G, 3 and 4 GridsLevel 2G, 3 and 4 Grids

Global Level 3 Products designed for climate modelers

0.05º Resolution Almost all products are

geographic (lat/long) Sea-ice is current exception –

in polar grid (Snow in C5)

Climate Modeling Grids

Climate Modeling Grids

(from BU – NBAR CMG – days 193-208, 2001)

99 Land Quality Assurance (QA)Land Quality Assurance (QA) QA is an integral part of the MODIS production chain Evaluates and documents the scientific quality of the

MODIS land products Built around central QA activity that coordinates and

integrates individual science team member QA activities Maintains: on-line global browse and time-series

tools, known issues web page, QA tool-kit

DAAC Unique Ordering Interfaces

See: http://modis-land.gsfc.nasa.gov/

Order from DAAC through EOS Data Gateway response is a few hours services (e.g. subsetting) available for some products

Get data from DAAC data pools most recently produced data are on-line

and available via FTP Get data from other sources (Science team sites,

MODIS Rapid Response, direct broadcast, etc.)

Land ValidationLand Validation Central validation coordination effort contributes to

and leverages off of international validation standards and activities

Primary techniques includes collection of and comparison with field and aircraft data, and comparison with data and products from other satellites; primary infrastructure is semi-permanent array of EOS Land Core Validation sites

C1

C3

C4

C5

Terra

Terra

Aqua

Terra

Aqua

Terra

Aqua

ReprocessingForward processingCn – Collection Version n

2000 2001 2002 2003 2004

Beta

2005 2006 2007

Validated (Stage 1)

Provisional

50003000 400020001000

0

1

S/MWIR

600500 550400 450350

0

1

VIS

0

1

LWIR

1400010000 1200080006000 160001100900 1000700 800600

0

1

NIR

20 reflective solar bands (0.4 - 2.2 µm) 16 thermal emissive bands (3.5 - 14.5 µm) Excellent radiometric and geometric accuracy Science team originally formed 13 years ago;

team re-competed in 2004 3 Disciplines: Land, Oceans, Atmosphere Leader: Dr. Vince Salomonson

1010

MODIS Land Collection 5 ChangesMODIS Land Collection 5 Changes55

Use improved Land/Water mask and new Land Cover map based on 3 years of Collection 4 data.

Refine surface reflectance by adopting a dynamic aerosol model in atmospheric correction and implementing BRDF coupling and adjacency effect correction schemes.

Improve quality of the Land Surface Temperature by revising the day/night algorithm and improving the detection and filtering of cloud contaminated observations.

Increase resolution of BRDF/Albedo product to 500m. Interpolate ancillary data to remove artifacts in the NPP product. Refine LAI/FPAR LUTs to improve numerical accuracy of the radiative transfer

simulations. Add fractional snow algorithm in the snow product Add burned area product.

NPP VIIRS Land Product EvaluationNPP VIIRS Land Product EvaluationNPPNPP

NASA NPP Land Science Team is evaluating VIIRS Land algorithms and data (post-launch) to determine if they are of climate data record quality

To help the science team perform this function, the VIIRS Land Product Evaluation System (PEATE) is being built using the MODIS approach (production, QA, etc.)

Land PEATE will: generate diagnostic products (e.g.,

gridded L3 multi-day products, browse, subsets) similar to MODIS

perform tests of possible algorithm improvements and their impacts on downstream products (e.g., time series test)

use operational software (with Direct Broadcast wrapper) and science software

support NASA radiometric and geometric calibration groups (NICSE) 1 of 5 PEATEs within the

NASA’s Science Data Segment (SDS)

Standard and Diagnostic Products

NOAA Production

System (NESDIS IDPS)

NOAA Archive (ADS/CLASS)

NASA NPP VIIRS Land Product Evaluation System (PEATE)

Standard Products

NASA NPP Land Science

Team

Possible Algorithm

Improvements

Standard Products

Possible Algorithm

Improvements

Lambert Azimuthal Equal Area (LAEA) – sea-ice products, polar projection

Lambert Azimuthal Equal Area (LAEA) – sea-ice products, polar projection

Sinusoidal (equatorial) –

7.5, 15 and 30 arcsec. resolution (roughly 250m, 500m and 1 km)

Sinusoidal (equatorial) –

7.5, 15 and 30 arcsec. resolution (roughly 250m, 500m and 1 km)

Level 2G/3: earth-gridded geophysical parameters

Level 4: earth-gridded model outputs Daily, 8-day, 16-day, 32-day, monthly

and yearly products 10º x 10º Tiles ( )

DB Workshop – Benevento, ItalyOct. 5, 2005