Preprocessing requirements

Before running this module, the following requirements must be met to ensure the job processes successfully and produces accurate results:

• Imagery is orthorectified
  The input imagery must be orthorectified, either by running the Orthorectification module, or by other means.

• Data is homogenous
  Typically, you create a mosaic by combining homogenous data. However, you can, if necessary, combine imagery from more than one sensor. If you do so, first consider whether the information is comparable. For example, achieving a suitable output mosaic may not be practical when the bands of the input imagery vary in wavelength.

• Imagery acquired under consistent conditions
  The more consistent the conditions, the better the results.

• Imagery free of features that affect color balancing
  Features, such as the presence of clouds, bright spots, or dark spots can affect the quality of the color balancing. It is recommended that you create local vector masks in the affected images to cover such areas to provide a better color-balancing result. Similarly, the module provides options for masking objects that can negatively influence cutline generation, such as clouds or building footprints. Masking out areas to avoid during cutline generation can help produce better cutlines.

  Alternatively, consider resolving color-balancing difficulties in CATALYST Professional Mosaic Tool. For information about Mosaic Tool, see the Mosaic Tool Help in CATALYST Professional.