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MEMO -TASK 89.1 <br />Geometric <br />correction <br />Radiometric and <br />atmospheric correction <br />NDVI Irrigated/Non irrigated <br />transformations mask <br />Crop type classification ~ Manual mapping of field <br />boundaries <br />Reference <br />data <br />Accuracy <br />Assessment <br />Figure 2: Flowchart of boundary mapping and irrigated crop classification <br />procedures in the SPDSS project area <br />5.1 Pre-processing and co-registration <br />The satellite image geometric correction requires geo-referencing the Landsat images to the UTM <br />coordinate system, Datum NAD27, Spheroid Clarke 1866. For this purpose, Ground Control Points <br />(GCP) will be obtained from Digital Ortho Quads (DOQQ). Once a single Landsat scene is geo- <br />referenced, the other dates for each image frame can be co-registered to the first scene. <br />Landsat 7 ETM is technically more advanced and has improved capabilities over its predecessors (e.g., <br />radiometric sensitivity that allows it to detect smaller spectral variations of the features on the ground). <br />Because of geometric and radiometric compatibility of Landsat5 TM and 7 ETM sensors, a <br />transformation will be applied to the Landsat5 TM data so that it matches the Landsat 7 ETM data. In <br />addition to the Landsat instrument calibration, it will be necessary to normalize image pixel values for <br />differences in sun illumination geometry and atmospheric effects. This improves the ability to mosaic <br />adjacent imagery and compare imagery over time (e.g., multi-date, multi-frame classification). <br />5.2 Spectral Enhancement for use in irrigated parcel mapping <br />A number of spectral enhancements can be applied to facilitate the interpretation and analysis of the <br />Landsat imagery and the consequent production of intermediate products and boundary maps. <br />Page 7 of 13 ~-~~versfde TecAnafagy, lnc. <br />W:rler Resources Frr~mec.•rng ,end L'nr+surlrn2 <br />