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<br />. <br /> <br />. <br /> <br />., , <br /> <br />The Tasseled Cap (TC) transformation preserves the euclidean relationships in the raw data, <br />but captures typically 95 percent or more of the total variability in three interpretable features. <br />Since TC is an invariant transformation, features are consistent between scenes, and can be <br />so interpreted once the data have been normalized for external effects such as haze level and <br />viewing and illumination geometry (Crist and Cicone 1984). The TM Tasseled Cap <br />transformation for TM reflectance data, published by Crist in 1985, will be used for this project. <br /> <br />The first three features of the Thematic Mapper TC include: Brightness (1); Greenness (2); and <br />Wetness (3). The contractor will be using the Greenness and Wetness features for the <br />irrigated acreage classification. TM Greenness responds to the combination of high absorption <br />in the visible bands (due to plant pigments and particularly chlorophyll) and high reflectance in <br />the near-infrared (due to internal leaf structure and the resultant scattering of near-infrared <br />radiation) which is characteristic of green vegetation (Crist and Cicone 1984). Wetness <br />contrasts the sum of the longer-infrared bands with the sum of the visible and near-infrared <br />bands to highlight moisture-related scene characteristics. Previous analysis has shown that <br />soil moisture is the primary characteristic expressed in Wetness (Crist and Cicone 1984). This <br />enhancement is expected to work well on the western slope valleys where irrigation generally <br />occurs and annual rainfall is less than 20 inches a year. <br /> <br />Principal Components Analysis (PCA) is often used as a method of data compression. It <br />allows redundant data to be compacted into fewer bands-- that is; the dimensionality of the <br />data is reduced. The bands of PCA data are non-correlated and independent, and are often <br />more interpretable that the source data (Jensen 1986; Faust 1989). The contractor will run <br />PCA's for all scenes in preparation for classification. The first two components of the PCA will <br />be used for signature editing, thresholding and classification. <br /> <br />Deliverable to State: <br />A task memorandum detailing the steps used in the image process. <br /> <br />Images: <br />One set of enhanced (Tasseled Cap (TC) and Principal Components Analysis <br />(PCA) images for each Landsat scene. TC will contain the Wetness and <br />Greeness features. PCA will contain components 1 and 2. Enhanced images <br />will be delivered in ERDAS .img format on CDROM. <br /> <br />Task 3 - Capture Polygons from 2000 DOQQ's <br /> <br />Upon review of examples of the 1993 Irrigated Acreage coverage from the pilot area cited in <br />the RFP, the Contractor will be capturing all field polygons from the 2000 DOQQ's and will not <br />attempt to edit the line work from the 1993 Irrigated Acreage coverage. The 1993 coverage will <br />be used as a backcover to serve as a visual quality check of the original data. Within each <br />Division's area of interest, the USGS Quad24 index will be used as a clip cover for the 2000 <br />coverage in order to make manageable coverage sizes. <br /> <br />Working in ArcEd it, to take advantage of numerous navigation, editing, coding, image display <br />and quality assurance AML routines, the 2000 coverage will be modified to reflect the <br /> <br />Page 14 <br />