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Product pages » Surface reflectance - MODIS, 19-band with atmospheric correction, Australia coverage

Surface reflectance - MODIS, 19-band with atmospheric correction, Australia coverage

Last modified by Matt Paget on 2015/02/25 14:22

Surface reflectance - MODIS, 19-band with atmospheric correction, Australia coverage

AustraliaClearASMRGB.jpg

Figure 1: Representative image of the clear sky surface reflectance of Australia. Bright areas (e.g., salt lakes) are highly reflective.

Link to the data

DescriptorData link
Dataset digital object identifier (DOI)
GeoNetwork recordhttp://data.auscover.org.au/geonetwork?uuid=8b0074d7-8c2c-441a-ba7e-93c4fa45ea20
HDFhttp://remote-sensing.ivec.org/thredds/catalog/RSSRG/SMAC/aqua/catalog.html (swath)
http://remote-sensing.ivec.org/thredds/catalog/RSSRG/SMAC/terra/catalog.html (swath)
http://remote-sensing.ivec.org/thredds/catalog/RSSRG/SMAC_GRID/aqua/catalog.html (grid)
http://remote-sensing.ivec.org/thredds/catalog/RSSRG/SMAC_GRID/terra/catalog.html (grid)

Update 5 June 2013: All ungridded (swath) and gridded data are now available. The process of shifting the data onto the THREDDS server is in progress.

Data licence and Access rights

ItemDetail
RightsCopyright 2011-2012 Curtin U. Rights owned by the Curtin University (Curtin U). Rights licensed subject to Creative Commons Attribution (CC BY).
LicenceCreative Commons Attribution 3.0 License, http://creativecommons.org/licenses/by/3.0.
AccessThese data can be freely downloaded and used subject to the CC BY licence. Attribution and citation is required as described at http://data.auscover.org.au/citation. We ask that you send us citations and copies of publications arising from work that use these data.

Alternate title

19-band reflectance, Simple Method for Atmospheric Correction (SMAC), Terra and Aqua MODIS Observations

Abstract or Summary

The AusCover Simple Method for Atmospheric Correction for MODIS product is an atmospherically corrected reflectance dataset derived from MODIS reflectance for all MODIS reflective bands (1-19 and band 26) for use in the development of advanced remote sensing products.

The Moderate Resolution Imaging Spectroradiometer (MODIS) was designed to meet the needs of the science community for frequent, high quality observations of global atmospheric, oceanic and ecological systems metrics and information. Much effort has been directed at validation and comparison of MODIS based ecological variables. Significant and complex issues remain in the use of the data over the Australian land surface, particularly over the Australian bright arid and semi-arid regional environments. These challenges include the accurate atmospheric correction of MODIS visible observations. Any limitations in the quality of atmospheric correction of MODIS data have implications for all products derived from visible observations. Recognizing this, TERN/AusCover developed an atmospheric correction algorithm for Australian MODIS land-surface observations that meets several specific needs:

  • Incorporates best available ancillary data sources;
  • Can be applied to current and historical MODIS observations;
  • Can be efficiently implemented on computing facilities available to AusCover, and;
  • Is easily extendible to provide VIIRS (or other instrument) atmospheric correction.

The Simple Method for Atmospheric Correction (SMAC) meets these requirements and forms the basis of the AusCover SMAC for MODIS (ASM).

Spatial and Temporal extents

ItemDetail
Spatial resolution (metres)1 km
Spatial coverage (degrees)99º to 167º E, -4º to -49º N
Temporal resolution1 day
Temporal coverage2000 to 2012
Sensor & platformMODIS Terra and Aqua
ItemDetail
Spatial representation typegrid
Spatial reference systemWGS 84

Point of contact

ItemDetail
NameHelen Chedzey
OrganisationDepartment of Imaging and Applied Physics, Curtin University
PositionScientific Programmer
Emailhelen.chedzey@curtin.edu.au
Roleauthor
Address
Telephone
URL
ItemDetail
NameProfessor Mervyn Lynch
OrganisationDepartment of Imaging and Applied Physics, Curtin University
PositionHead, Remote Sensing and Satellite Research Group
Emailm.lynch@curtin.edu.au
RolepointOfContact
Address
Telephone
URL

Credit

Landgate Satellite Remote Sensing Services http://www.landgate.wa.gov.au.

Keywords

ThesauriKeyword
GCMDEARTH SCIENCE > LAND SURFACE > SURFACE RADIATIVE PROPERTIES > REFLECTANCE
CFsurface_reflectance_where_land
FoREnvironmental Sciences > Ecological Applications = 0501

There are three main thesauri that AusCover recommends:

  1. Global Change Master Directory (http://gcmd.nasa.gov)
  2. Climate and Forecast (CF) convention standard names (http://cfconventions.org/standard-names.html).
  3. Fields of Research codes (http://www.abs.gov.au/ausstats/abs@.nsf/0/6BB427AB9696C225CA2574180004463E?opendocument).

Data quality

This current release is version 1 of the ASM product.

Validation status

This is a pre-validation release of the ASM product.  Limited data comparisons have been made between MOD09 values and the SMAC-derived reflectances. In situ reflectance data from 7 different AusCover field sites are currently being used in a validation study.

Related products

ItemProduct link

References

ItemDetail or link
Methodology DocumentHelen Chedzey, Mark Broomhall, Brendon McAtee, Mark Gray, Peter Fearns, Mervyn Lynch (2013), Methodology Document and Data Users Guide: Australian Region Atmospheric Correction for MODIS Visible Band Observations, Final Version (May 2013), pp.28. PDF
Validation report
Online info

Algorithm summary

Full details are provided in the Methodology Document.

MODIS reflective bands cover the wavelength range 460 - 2130nm. In this region of the electromagnetic spectrum the physical quantity measured by the satellite is termed the Top-Of-Atmosphere (TOA) radiance. For applications of remote sensing of surface properties the Bottom-Of-Atmosphere surface Reflectance (BOAR) is the required parameter. ­­

The BOAR may be computed from the TOA radiance measured by the sensor based on an underlying knowledge of radiative transfer within the atmosphere between the surface and the satellite sensor. This process is termed atmospheric correction and requires characterization of the atmosphere.  MODIS reflective bands (1-19 and 26) atmospheric correction require accurate estimation of atmospheric water vapour (TWV), total column ozone (TCO) and Aerosol Optical Depth (AOD). The atmospheric correction is described by Vermote and Vermuelen (1999) and is parameterized by Rahman and Dedieu (1994).

The AusCover SMAC Modis (ASM) has minimal ancillary data requirements. As indicated above there are three ancillary parameters that must be supplied: Column Water Vapor, Column Ozone Concentration and Aerosol Optical Depth. In the current (Dec 2011) preliminary data release the following are used:

  • Column Water Vapor - GDAS 1˚ (grib format)
  • Ozone Concentration - TOMSOMI 1˚ Ozone
  • Aerosol Optical Depth - Globally set to 0.05

Future implementations of the ASM will use AusCover resources for ozone, water vapor and aerosol optical depth wherever possible. It is expected that higher resolution data from the Bureau of Meteorology scheduled to be made available through AusCover data services will offer improvements in resolution and accuracy over the global grid analyses or estimates currently used for operational processing.

Product version history

Version labelDetail
1.0Initial release

Metadata history

DateDetail
2011-06-29Metadata creation date
2013-02-16Reformatted to new template.
Tags:
Created by Matt Paget on 2013/02/17 01:00

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