SPDSS_GISScope4_20060711 - Laserfiche WebLink

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• Background: The 2001 SPDSS irrigated lands mapping program used a consistent method of preprocessing satellite imagery that was thoroughly tested, validated and is repeatable. The data sources and consistent processing methods could be extended to the entire CDSS mapping program. The SPDSS approach included consistent atmospheric correction, processing for areas of cloud cover, and orthorectification procedures that enabled multi-date image classification and analysis. The SPDSS approach also developed standard and well-documented methods for creating NDVI layers and related products for consistent and repeatable analyses. Consistent processing of statewide Landsat images offers a number of advantages to the State, including cost-savings. Landsat 5 is operating far beyond its design life and may fail at any time. Landsat 6 never achieved a successful orbit and Landsat 7 has been delivering degraded data since 2003. The U.S. Congress has recently approved a replacement satellite, however, it will take several years before it is operational. NASA currently supports other satellites that have much potential for supporting the objectives of the CDSS, potential alternatives that require clarification to assist with medium-term planning. MODIS is a candidate whose data are available at no cost. MODIS has a more frequent return period than Landsat that may offer CDSS several advantages that compensate for its coarser spatial resolution. Approach: 90.3 Imagery search and selection. Conduct a careful, comprehensive search and identification of best available Landsat 5 imagery using on-line search tools. Selection process will optimize for imagery dates representing key crop types with minimal cloud cover. Coordinate with the State on image selection process, and with the State and other agencies to identify existing imagery for 2005. 90.4 Landsat image processing. Process the statewide Landsat Imagery using consistent standards developed under the SPDSS. Imagery will be processed to the NDVI level and be prepared for classification by State Personnel. 90.5 Report on Landsat image processing procedures. Prepare technical memorandum describing complete flow of image processing methods, and metadata. Identify and describe any scene- or subscene- specific detailed processing methods used to remedy issues contained within scenes (e.g. cloud cover, data gaps, etc.). 90.6 Compare and contrast MODIS with Landsat and assess MODIS applications potential for CDSS. The ability of MODIS to meet CDSS requirements will be quantitatively determined using the Landsat benchmark. Mapping of irrigated parcels using MODIS will be evaluated in order to understand the optimum mapping threshold (OMT) of MODIS at all CDSS mapping scales. This evaluation will assess how effectively MODIS can map irrigated parcels of different sizes, and how well individual crop types can be delineated. Once this evaluation is complete, tests of potential applications will be conducted that rigorously define the utility MODIS may have for irrigated lands mapping. Specifically, we will define the size of parcels that can be reliably mapped and investigate the utility of mapping entire service areas. Results will be used to evaluate the total irrigated land in Colorado that could be effectively mapped with MODIS. The potential for developing new, enhanced CDSS applications, such as annual updates of irrigated lands to be used in consumptive use modeling, will also be evaluated. Deliverables: 90.3, 90.4, 90.5 Memorandum describing complete flow of image processing methods and data considerations. 90.4 Pre-processed Landsat data including original and final pre-processed individual multispectral imagery, NDVI imagery, and full metadata utilizing FGDC compliant metadata format. 90.6 Memorandum: (i) Comparing MODIS to the CDSS Landsat benchmark; (ii) Summarizing the utility and limitations of MODIS for CDSS applications; (iii) Evaluating MODIS potential for annual updates of 4