McIDAS-V Tutorial: Manipulating GeoTIFFs

Transcription

1 McIDAS-V Tutorial: Manipulating GeoTIFFs

2 Contents 1. Getting Started Installing the GNCA_Sep2016 Plugin Selecting and Displaying GeoTIFF Images Applying Color Tables and Projections Saving the Display as an Image Saving the Bundle File Additional Practice McIDAS-V Shortcuts Getting Started McIDAS-V This tutorial assumes that you have already installed McIDAS-V on your computer. McIDAS-V is a visualization and data analysis software package. For a list of references, the following online documentation page includes a current user s guide, tutorials and instructional videos: GeoTIFF TIFF is the file name extension used for the Tagged Image File Format, where GeoTIFF is a metadata format that has the added ability to embed georeferencing information within the image data. This includes map projection and coordinate systems in order to establish the spatial reference for the file. This guide explains the basics of manipulating a GeoTIFF file in McIDAS-V. McIDAS-V Tutorial: GeoTIFF 1

3 2. Installing the GNCA_Sep2016 Plugin 2.1 Download the GNCA_Sep2016.jar plugin file and save it to a local directory. a) For example, C:\Program Files\McIDAS-V-System\McIDAS_Plugins. 2.2 Open McIDAS-V. The following 3 windows will pop up: a) Help Tips gives helpful hints (you can close this window) b) Main Display Window shows a map projection and any selected data c) Data Explorer where data is selected *NOTE: When you start McIDAS-V the Data Explorer window will open automatically. If you accidentally close it or have multiple open, you can pull up the one belonging to a given Main Display window by clicking on the blue McIDAS-V icon in the top left of the Main Display window. McIDAS-V Tutorial: GeoTIFF 2

4 2.3 Go to the Main Display window (with the map). From the tab bar select: Tools Plugins Manage 2.4 The Plugin Manager window will open. From the tab bar select: File Install Plugin From File 2.5 Navigate to local directory where you saved the GNCA_Sep2016.jar plugin file and select it. Click the Open button. 2.6 You will be prompted to close out of McIDAS-V and restart the program to complete the installation. Closing the Main Display window will close the entire McIDAS-V program (this is what you want to do here) while closing the Data Explorer window will only close that window. 2.7 After you have restarted McIDAS-V, return to the Plugin Manager. You will now see GNCA_Sep2016.jar under Installed Plugins. To remove the plugin later, this is where you would go. McIDAS-V Tutorial: GeoTIFF 3

5 3. Selecting and Displaying GeoTIFF Images 3.1 Download the example GeoTIFF data files for GOES-East and put them in a local directory. In this example they are put in directory D:\GNCA\data\geotiff_GOES_EAST. 3.2 Load the GeoTIFF data files into McIDAS-V. Pull up the Data Explorer window and click on the Data Sources tab if it is not already selected. a) In the column on the left expand the General heading. Then select Files/Directories. b) From the Data Type menu, select TIFF files. c) From the Look In menu, select the directory where you have put the files. In this example they are found in D:\GNCA\data\geotiff_GOES_East. d) Select an individual GeoTIFF file to load, starting with GoesEast_01V _Barbados.tif. The 3 files used in this example correspond to the region around Barbados on April 7, 2015 (Julian day 097) at the time of 16:45 UTC. e) Click the Add Source button. f) Click back on the Data Sources tab, and repeat steps a-e for the additional 2 files, GoesEast_04I _Barbados.tif andgoeseast_04i _barbados.tif. McIDAS-V Tutorial: GeoTIFF 4

6 a b c d e McIDAS-V Tutorial: GeoTIFF 5

7 3.3 Display the images. Click on the Field Selector tab if it is not already selected. a) Under the Data Sources column you will now see a heading named Formulas, as well as the 3 GeoTiFF files loaded in step 2. Click on Formulas. b) Under the Fields column, expand the GNCA heading. c) Double-click GOES IR µm BT geotiff to show the Field Selector window. d) Expand the heading for the GoesEast_04I _Barbados.tif file. Select GoesEast_04I _Barbados.tif Grid data. e) Click the OK button to load the display. a b c e d 3.4 View the Main Display window to see what happened. Loading the image may take 5-10 seconds, depending on the speed and memory of your computer. By clicking on the image with the mouse scroll wheel*, the value at that location will be displayed in the lower right corner of the window. The image is automatically displayed as Brightness Temperature in units of Kelvin. *NOTE: If you are using a laptop computer with a touchpad instead of a mouse, you will need to set the navigation controls in the user preferences (see Section 8). If the imagery is not mapped correctly when loaded, you can try changing the projection. From the Main Display window, select Projections Predefined Americas. Use the navigation controls to the left to zoom in on your region of interest. McIDAS-V Tutorial: GeoTIFF 6

8 1st image: GOES IR 10.7 µm cursor when holding down the mouse scroll wheel cursor readout in Kelvin 4. Applying Color Tables and Projections 4.1 We are able to change the color table from the Data Explorer window. 4.2 Click on the Layer Controls tab if it is not already selected. Click on the Color Table button that says Gray Scale. Then select GNCA SVGAIR_TEMP. McIDAS-V Tutorial: GeoTIFF 7

9 4.3 In the Main Display window, the image will look a little strange. The min and max values for the color table need to be changed to their standard values. a) In the Data Explorer window under Layer Controls, click on the Color Table button that now says SVGAIR_TEMP. b) Select Change Range and a new window will pop up. c) Click on the Use Predefined button. d) Select From Color Table. e) Click the OK button and view the display to see the new color range. a b c e d McIDAS-V Tutorial: GeoTIFF 8

10 4.4 The image is automatically displayed in units of Kelvin, which we will now change to degrees Celsius. a) In the Data Explorer window under Layer Controls, click on the Edit tab. b) Select Change Display Unit and a new window will pop up. c) Use the New unit drop down menu and select C. d) Click the OK button. a b a d c McIDAS-V Tutorial: GeoTIFF 9

11 4.5 Add the color bar to the display image. a) In the Data Explorer window under Layer Controls, click on the Edit tab. b) Select Properties and a new window will pop up. c) Click on the Color Scale tab. d) Check the box next to Visible, for position select Top, increase the font style to Bold and size to 18 and change the color to white. e) Click the OK button, then view the display. a b e d c 4.6 Use the cursor readout to interrogate the data. What features can you identify? Where is it coldest/warmest? McIDAS-V Tutorial: GeoTIFF 10

12 5. Saving the Display as an Image 5.1 To save the current display as an image, go to the Main Display window. Click on View Capture Image. 5.2 A new window will pop up where you can choose the location to save the image, the file name and the type of file. Additionally, you can specify the extent of the view to capture, the quality, and if the background is transparent. 6. Saving the Bundle File 6.1 You are also able to save your current McIDAS-V configuration, including the data sources in use, parameters displayed and settings. To create a bundle file, go to the Main Display window and click on File Save Bundle. 6.2 A new window will pop up where you can choose the location to save the bundle and the file name with.mcv extension. 6.3 To open a previously saved bundle, go to the Main Display window, click File Open File and browse to locate the file. McIDAS-V Tutorial: GeoTIFF 11

13 7. Additional Practice 7.1 Repeat the above steps to now look at water vapor imagery: a) Start with Section 4, Step 3 b) Select GoesEast_04I _Barbados.tif for water vapor imagery c) For Formula, use GOES WV (I3) 6.5 um BT geotiff d) Apply the GNCA SVGAWVX_TEMP color table e) Change the range to Predefined From Color Table f) Change the unit to C g) Add color bar to the display 7.2 Repeat the above steps to now look at visible imagery: a) Start with Section 4, Step 3 b) Select GoesEast_01V _Barbados.tif for visible imagery c) For Formula, use GOES VIS Albedo geotiff d) Apply the GNCA Square Root Visible Enhancement color table e) Manually change the range from 0 to 70 (for % albedo) f) Add color bar to the display McIDAS-V Tutorial: GeoTIFF 12

14 7.3 Each image will be a separate layer in the Main Display window and can be viewed or hidden using by checking or unchecking the boxes to the left. 7.4 You can also loop through the 3 images. In the Main Display window, click on the View tab. Select Displays Visibility Animation On. Here you can choose to loop through the layers faster or slower. a b c d McIDAS-V Tutorial: GeoTIFF 13

15 8. McIDAS-V Shortcuts McIDAS-V Tutorial: GeoTIFF 14

16 8.1 To use the cursor readout feature on a laptop, you will need to change the navigation controls in the user preferences. a) From the Main Display window, select Edit Preferences b) In the User Preferences window, click on Navigation Controls in the left column c) Under Navigation Mode at the top, select Custom d) For Left (MB1) and Control, use the drop-down menu to select Cursor/Data Readout e) Click the OK button f) You should now be able probe the data by holding down the Ctrl button while clicking the bottom left corner of the touchpad a b c d e McIDAS-V Tutorial: GeoTIFF 15