Multispectral Product Operation Editing
On this page, you will find general help for the ProRaster product family including links to documentation, instructional videos, and training videos.
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The ProRaster User Guide is available for download as a PDF.
Each operation in a product contains inputs, which include rasters and operation properties, and generates an output, which is usually a virtual raster. By connecting operations together into chains and by branching off new operation chains, you build a waterfall-style operation cascade. If you change the inputs or properties of any operation in the tree, all the operations downstream of that operation will update and regenerate output.
You can edit any operation by double-clicking on it in the tree, or by selecting the operation in the tree and, on the “Operation” property page, hitting the “Modify and Run Operation” button.
At the top of the tree is the original product (Scene, Collated Scene, etc…). The product was created by choosing one or more scenes or one or more products and, possibly, defining other properties like a mask band. You can edit this item and change the scene or product, or collection of scenes or products, that were used to generate the product.
If you edit a Scene product, you will be presented with the scene browser dialog and can select a replacement scene. In all other cases, you will be presented with a dialog that shows the list of scenes in the product and allows you to add new scenes, delete existing scenes, and reorder the scenes. An example is shown below for a Collated Scene.
The scenes are listed from “top” to “bottom”. In most products, scenes are composited using a painter’s algorithm where data from scenes underneath are overprinted by data from scenes on top. The scene list reflects this order. When you add a scene to the list it will open the scene database browser and you will be able to select a scene.
You can reorder the scenes manually by selecting a scene and clicking the move up or move down buttons. A more effective way to order the scenes is to drop down the order menu button. This provides the following options.
In almost all cases it is advantageous to order by cloud coverage. You can use cloud coverage for the entire scene, or cloud coverage for the land-classified pixels in the scene if this information is available. The scenes with the least cloud coverage will be placed at the top so that this higher-quality data overprints other scenes that are compromised by higher levels of cloud coverage.
Alternatively, you can order by acquisition date. Usually, you would order the scenes from earliest (oldest) to latest (most recent). In a scene sequence product, this order is enforced. In a collated scene or collated mosaic, you are combining multiple masked nearly contemporaneous scenes. You may want to sort the scenes by proximity to a central (ideal) scene or a specified date. In other words, you are trying to use as much data that is as close to the ideal acquisition date as possible. To sort the scenes so that they are closest to a specific scene, select the scene in the list then choose the appropriate sorting option. The manual option will present a dialog for you to enter the target date and time.
There are restrictions on what scenes you can choose to add to any existing product. The system may force you to select a scene that is the same tile as the original scene. It may force you to select scenes that are spectrally compatible with other scenes in the product. If you choose a scene that is spectrally different, then the downstream processing operations may need to be edited to correct problems that arise from changing the field and band structure of the raster.
If you edit a product that draws from multiple source products (like a collated scene sequence for example), you will be presented with a dialog that shows the list of products in the product and allows you to add new products and delete existing products. An example is shown below for a Mosaic Sequence.
Hit the “Add” button to add a new product to the sequence. You will be prompted to select a product database, and then to browse for the product. Select the product in the spreadsheet and hit OK.
Hit the “Delete” button to remove a product from the sequence. This does not delete the original product.
All the products you edit with this dialog will be sequences and so the order of the products is fixed and determined by the product event time. The products in the list will automatically be sorted from latest time to earliest time (top to bottom).