Introduce the student to the initial concepts and use of IDL and ENVI to: • import, analyze, and output image data. • learn to interface between ENVI input/outputs. This tutorial is designed to introduce you to the basic concepts of the ENVI software and some of its For ENVI +IDL, type envi at the UNIX command prompt. These programs (scripts) are based on the IDL programming language and are run in the IDL environment, either by loading the ENVI+IDL program or simply.

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Using the fourth field above as an example, the format tutoriaal as follows: The plot function is applied to the data, and the resulting data are returned to the plot window where they are displayed. The Spectral Library Viewer dialog appears.

This applies only to Z Profile windows and will be undefined for all other plot windows.

ENVI Tutorial

Of course for any geospatial work outside IDL you would need to know the nominal pixel size and coordinates of at least 3 control points for dnvi registration. A read of Michael Todd’s above note with the link to a class exercise at UIdaho should help you with syntax of the code. Yudine, should there be an attachement or some details? By clicking “Post Your Answer”, you futorial that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

The Open File dialog appears. A file selection dialog appears.

If the plot function is defined without this keyword, then you will likely receive errors when trying to use it in ENVI. When you call a user plot function, normal plot data all the spectra in the plot window are passed to the user plot function.


For this tutorial, you will copy a previously edited version of u s e r a d d. Yudine 27 1 3.

remote sensing – Reading BSQ file format in IDL? – Geographic Information Systems Stack Exchange

Sign up using Facebook. We’ll need more info to provide a better answer. Vector whose values identify the band positions of the bad bands in the Z Profile data. Note that 1st Derivative will be placed immediately after the Binary Encoding menu option. Vector of ones and zeros with as many elements as x-axis data points. V Stuart Foote 5 Note the fourth and fifth lines: The following code appears in the IDL Editor: ENVI calculates the first derivative spectra of all plots and displays the results in the Spectral Library Plots window.

Home Questions Tags Users Unanswered. Excluding the bad bands, the isl takes the first derivative of the y value and returns it to the plot window. Voir plus Voir moins. A Spectral Library Input File dialog appears. The user plot function is applied to every spectrum placed in that window until a different plot function is selected. However, while ordinary user functions are automatically called by XMANAGER and receive the event structure variable as a positional parameter, plot functions are automatically called by ENVI and receive several variables as both parameters and keywords that are related to the data in the plot window.

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Introduction to IDL Programming

This file contains the following code. The following steps outline this process. Post as a guest Name. All user plot functions must have the following function definition statement: And the byte order is 0, i. Post Your Answer Discard By clicking “Post Idk Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.


When you understand how these functions work, close the files. Then your only issue will be deciding which bands in the array to display, to combine. On a Windows platform, this directory is in the following location where x x indicates the software version: Define user plot functions by ivl a new line to the useradd.

This information is often stored in a. This function accepts x and y data and a list of bad bands. Keyword tutoral that must be present to receive extra variables that ENVI may need to pass into the plot function.

A value of 1 indicates that the corresponding y-axis value is good, and a value of 0 means it is bad i. Tag that indicates the following definition is a plot function since u s e r a d d.

Earth System Analysis | Geological Remote Sensing Group

Not sure it this will help. ENVI calculates the second derivative spectra of all plots and displays the results in tugorial Spectral Library Plots window. Documents Ressources professionnelles Informatique. Yudine, looks like you have every thing you need to read the image into an IDL array. IDL seems to support reading tif files. Select one or more spectra; the corresponding spectral profiles appear in a Spectral Library Plots window.

Data type 2 integer probably