Using Marigold
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      The Spectral Query Tool

      Marigold 2.6.0 brings a totally revamped spectral query tool. Let's get querying!

      The Spectral Query Tool

      The spectral query tool forms the backbone of advanced spectral analysis in Marigold, serving as the primary point of pixel interrogation as you learn the properties of your area of interest. The latest Marigold release (2.6.0) contains a major overhaul of this tool that provides users with more precise control over point selection, query naming, band ranges, and source products. The goal of these changes is to make spectral investigations more efficient so that users have added flexibility while selecting spectra without cluttering their spectral collection.

      We think the new tool is quite intuitive, but if you'd like to learn all the details and some tips, follow along below.

      Using the New Spectral Query tool

      To use the new tool, select Spectral Query from the dropdown next to the Spectra section of the lefthand panel.

      Note: You may notice that the additional menu options have also changed. The spectra menu has been simplified to group features that either 1) add spectra to the project (e.g., instrument spectra, average spectra from a vector, and spectral libraries), or 2) export spectra from the project. 

      Selecting Products and Bands

      The new tool will open as a panel on the righthand side of Marigold. At the top, select a spectral product and modify the band selection if needed. For example you could toggle only the VNIR bands from the Fused Bare Earth Composite, or select a range of bands from 2000-2500 nm from an EnMAP scene.

      To visualize the bands you will be querying, click Update band selection to view an overlay of those bands on the spectrum plot below.

      The product and band selection features in the new spectral query tool allow users to precisely control what they are sampling as they prepare to collect in-scene spectra. The spectra plot now shows users the wavelength location of bands in each product.

      Once you've selected your product and bands, it's time to start querying. With the new tool, you will be able to take repeated spectra measurements while the tool is open without your selections being added permanently to the project. Users now have the option to rename and change the color of each spectrum before they decide to save it.

      Querying the Scene

      Click Start querying to begin collecting spectra. Click points on the map to obtain the spectrum for that pixel. The spectrum will appear on the spectra plot in the tool. The   You can continue clicking and collecting spectra until you either right click the map. 

      Collect as many spectra as you like from the scene and see how they compare live on the spectral plot as they are generated! You can even change the product and compare spectra from multiple sources at once.

      Rename and customize your selections

      Once you are happy with some or all of the spectra you have sampled, you now have the chance to rename and modify the line color of each spectrum and discard any that you don't need. The checkbox toggle next to each spectrum name determines which samples that will be saved. When ready, click Add selected spectra to close the dialogue and add your spectra into the lefthand spectra list.

      That's it! Once the spectra have been added to your workspace, you can continue your spectral analysis in Marigold. Happy exploring!