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To get started using Giovanni and NEO, it is first necessary to know how to do some of their basic functions: choosing data, selecting a time period, selecting a region, creating images, and then selecting one of the various ways to analyze the data. This Functions page describes how to do basic functions like these in Giovanni and NEO.
NEO Functions
The first step in NEO is to choose a dataset to analyze. On the NEO home page, there is an image of the Earth, with several choices below it. Clicking on Ocean provides the list of ocean-related datasets in NEO:
Selecting "Chlorophyll Concentration (MODIS)" will generate the image of global chlorophyll concentrations seen above. Below the image and list of datasets will be a list of all of the data product files of this type in NEO. To select one, click the small "+" sign in the box. This will generate the following pane:
To select the image for analysis, click on "Analyze this image". The file will appear on the right side of the page. It is possible to do this for two more files; the files can even be different data products. Once the files are selected, click on "configure/launch analysis". The next page will look like this:
The tabs provide several different options. The most important one for basic analyses is "Select Area". When this is selected, the image appears, and a box can be defined by clicking and dragging with the mouse. When the desired area is selected, click the "Select" button and a yellow "Region Saved" message will appear. Then click "Launch Analysis".
As an example, the Gulf of Mexico and Caribbean Sea region was selected. The analysis page will appear similar to the image below:
To the right of the image are the different analysis options. Here are brief descriptions of what they do.
Zoom & Roam: Click on the image to magnify a particular area.
Restore: Return to the original size image.
Probe: Show the latitude and longitude and data value at the cursor location.
Plot Transect: (shown in the image) Draw a transect line, and see the values plotted along the line from the start point to the end point. The result of this transect is shown below.
Distance: Draw a transect line and the length of the line on the map will be displayed in kilometers. If more than one data file has been selected, the values for each file will be shown.
Select Region: Select a rectangular region. The total area of the selected area and the average value of the data product for this region will be displayed in the rectangle.
Outline Region: This option allows a free-form area, rather than a rectangular area, to be selected. It takes practice, but just about any shape can be drawn. The total area and the average value for this area will be displayed on the image.
Histogram: For either the "Select Region" or "Outline Region" functions, clicking Histogram will display the distribution of data product values in the selected area. If more than one data file has been selected, the values for each data file will be shown.
Print Image: Prints the image.
The "Pick a color table" menu allows selection of different color scale options, if they are available.
That is a brief description of the basic NEO data acquisition, image generation, and analysis functions! NEO also allows you to download the full results of an analysis session to your computer, and to download the full data files to your computer. Those functions are not necessary to use this cookbook to investigate ocean regions and processes.
Proceed to the Giovanni Functions page >
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Atmos Composition
