Browsing the Multispectral Scene Database
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.
You interact with scene databases via the “Browse Scenes” menu button.
If you click on the button, it will open a browser for a scene database. If you have more than one scene database, then a dialog will open allowing you to choose which scene database you wish to browse. Double-click on the database in the list or select the database and hit OK.
The scene database browser dialog contains a world map at the top and a spreadsheet at the bottom. Each scene in the database is represented by a row in the spreadsheet.
The map shows the terrain and countries of the Earth. The spatial extent of each scene in the database is shown on the map as a red rectangle. Zoom the map with the mouse roller and pan by left-clicking and holding, then dragging. As you move the cursor about the map a tooltip sows the coordinate of the cursor. If you are hovering over a scene, the ID of the scene will be shown also.
The purpose of the browser is to allow you to find and select a scene, or a group of scenes, from which you want to create a product. To help you achieve this, you can make queries. You can make a query from the map or from the spreadsheet. A query will probably reduce the number of scenes in the spreadsheet, which is reflected in the map. At the bottom left are two buttons that allow you to execute or reverse a query.
If you left mouse button double-click in the map you can make a spatial query that selects all the scenes that intersect the location that you clicked. You can also zoom and pan in the map, then right mouse button click to bring up the context menu and hit “Select visible scenes”. This will execute a spatial query that selects all scenes that intersect the map bounds.
In the spreadsheet, you can execute a query by selecting one or multiple rows (scenes) in the sheet, and then hit the execute query button (forward arrow). This will collapse the spreadsheet to only those selected scenes.
Often you will want to find scenes by filtering by platform, bird, processing, and other scene parameters. Click on the column header to sort the spreadsheet by the column. Scroll down to find the parameters you are interested in. Left mouse button double-click on the cell and the browser will select all the rows that have matching data in that column. You can then hit the execute query button to collapse the sheet to those selected scenes.
The map may not always display all scenes in the database. This will depend on the map projection employed. Right-click on the map and, from the context menu, hit “Projection”. You can choose from Standard, WebMap, Globe, North Pole, and South Pole.
Right-click on the spreadsheet column header to control the column widths and to choose which columns are displayed in the sheet. These data items are acquired from the metadata for the scene.
If you select a scene and right-click on it, a context menu will provide you with options to display or render that scene or to create a product from that scene, or that group of selected scenes.
Rendering a scene
In the scene browser, select a scene and right-click to bring up a context menu. You will be presented with options to “Display scene”, “Render scene” and “Export scene”.
Choose “Display scene” to open the key scene MVR file in a default algorithm in the main ProRaster interface. It chooses a Look-up Table color layer, so you can explore all the fields, bands, and events of the raster. If you wish to keep the algorithm, use the normal mechanism to save it to an MRD file.
Choose “Render scene” to open the key scene MVR file in a default algorithm in the main ProRaster interface. In this case, it uses a RGB layer and it needs to assign spectral bands to the red, green, and blue color components. The following dialog is displayed to enable you to exercise control over the band assignments.
Creating a product
The main purpose of the scene database browser dialog is to enable you to select one or more scenes from which to create a multispectral product. Building a product takes you on a road towards data analysis of the scene(s). The product is written into a multispectral product database and can be edited using the multispectral product editor dialog.
From the scene database browser, you can make five types of products directly.
The simplest product, consisting of a single scene. The raster input to the product is just the key MVR virtual raster associated with the scene.
Select any scene (row) in the database and right-click to create a scene product.
A single scene, constructed by merging two or more nearly contemporaneous visits of the same tile. You must specify a raster mask to differentiate between high-value pixels (which are retained) and low-value pixels (which are discarded). Low-value pixels discarded from one scene may be replaced by high-value pixels from another scene in the stack. The raster input to this product is a new MVR that combines the input scenes using a raster mask operation.
Sort the database by tile and then by acquisition time. Select two or more scenes that are spectrally matching (same satellite family, same processing and processing level, same product, same tile) and as contemporaneous as possible. Right-click to create a collated scene product.
A single tile, with multiple events. Combine two or more visits of the same tile by declaring each visit to be an event in the raster. This provides a new dimension to the raster dataset – a time dimension. It can be imagined as frames in a movie. The raster input to this product is a new MVR that combines the input scenes and declares the events.
Sort the database by tile and then by acquisition time. Select two or more scenes that are spectrally matching (same satellite family, same processing and processing level, same product, same tile) and at the acquisition times that you want to target. Right-click to create a scene sequence product.
Two or more adjacent scenes merged to produce a single raster dataset. Where tiles overlap, the order of the scenes in the mosaic determines which data will be retained in areas of overlap. The raster input to this product is a new MVR that merges the input scenes.
Sort the database spatially. Select two or more scenes that are spectrally matching (same satellite family, same processing and processing level, same product, same tile) and as contemporaneous as possible. Right-click to create a mosaic product.
A mosaic, where one or more of the scenes is collated from two or more scenes. The raster input to this product is a new MVR that combines and merges the input scenes using a raster mask operation.
Sort the database spatially. Select two or more scenes that are spectrally matching (same satellite family, same processing and processing level, same product, same tile) and as contemporaneous as possible. Right-click to create a collated mosaic product.
Sometimes, when you select a group of scenes, you are given the option to create a [Partial] product. This indicates that it can make a product of the indicated type from the selected scenes if one or more of the scenes is not included. If you choose this option, the scenes that are not suitable for inclusion in the product will be excluded.