Category Archives: Tips and Tricks

List of band math/ spectral math function in ENVI

Applying mathematical operation on satellite image is an important processing step in remote sensing project. Lots of software such as MATLAB, ENVI, ERDAS and PCI Geomatica enable users to carry out these operation . However, the user interface and how to implement the operation into the software make them different with one another. Some software required basic knowledge of programming while other give more user-friendly and easier interface for the beginner. Above all software, one of the easiest software to perform simple mathematical operation on satellite images is by using ENVI.

In ENVI, the tools is called band math. (Basic Tool>Band Math)

Band math in ENVI enable user to perform basic mathematical operation, trigonometric function and  other option such as Boorlean and relational operators. Today, i like to share about the list of mathematical band math operation in ENVI.

  1. Addition (+)
  2. Subtraction – (-)
  3. Multiplication – (*)
  4. Division – (/)
  5. Minimum operator – (<)
  6. Maximum operator – (>)
  7. Absolute value – (abs(x))
  8. Square root – (sqrt(x))
  9. Exponent  – (^)
  10. Natural exponent – (exp(x))
  11. Natural logarithm – (alog(x))
  12. Base 10 logarithm – (alog10(x))
  13. Sine – (sin(x))
  14. Cosine  – (cos(x))
  15. Tangent – (tan(x))
  16. Inverse sine/ Arcsine – (asin(x))
  17. Inverse cosine/ Arccosine – (acos(x))
  18. Inverse tangent/ Arctangent – (atan(x))
  19. Hyperbolic sine – (sinh(x))
  20. Hyperbolic cosine – (cosh(x))
  21. Hyperbolic tangent – (tanh(x))

There are still few more functions, however the list above is the most used ones in ENVI. Thanks you and don’t forget to bookmark us (Ctrl + D).

(Tips) The fastest way to determine or check journal impact factors

Hi all,

In some cases, during research you will encounter some journals that you’re not familiar with. Hence, it is important to determine its impact factor as it is the fastest way to decide how much reliable the journals are. Hence, if you’re trapping in the mentioned problem, feel free to visit this website . Impactfactorsearch.com provide the fastest way to find the journal impact factors. Besides, it also provide the latest ranking of impact factors.

Here an example, we search latest impact factors for Remote Sensing of Environment journal.  Based on the picture below, it give the current ranking of impact factor (2012). Easy enough right?

Image

Hopefully, by using the website, it help you guys to evaluate the reliability of the journal.

Btw, feel free to check list of remote sensing journals with their impact factors (2011) and list of remote sensing journals with their impact factors (2012). Thanks you.