ERDAS Imagine is an excellent software suite designed to stand alone or provide interoperability with other spatial analysis software such as ESRI's ArcGIS. This weeks look into remote sensing has dealt with two things; a good look at the spectrum of Electromagnetic Radiation (EMR), and an introduction into ERDAS Imagine through some image files. The overall goals here were to understand some of the key concepts about EMR to put more substance behind the images we have looked at the past few weeks, and to look further into how we can manipulate the information in these images.
Lets first get a glimpse of the Electromagnetic spectrum to start things off.
This is the spectrum looking at long waves on the right and short waves on the left and watching their transition from one side to the other. Happily we have our nice visible portion there in the center. What you need to understand here is that everything in our world is an emitter, reflecter, or absorber of energy falling somewhere on this spectrum. There are also things like the sun which emit energy in a continuous amount of energy across the entirety of the spectrum. All of the EMR sent out by the sun then interacts with our atmosphere or things it comes in contact with which it either reflects off of, is absorbed by, or is refracted from. Remote sensing cameras then get to absorb some of this EMR for us to view. From there we then get to manipulate the imagery we get into usable products like the below.
This is a very simplistic map which was built as an example of some basic processing from ERDAS Imagine. The image itself was first used in ERDAS to calculate the area of each category represented here. There are different classes of vegetation and land cover shown. You might also notice than when the remote sensing platform originally took the image there was something else we couldnt classify as ground cover... Clouds. Clouds occupy 507 acres of the image. from ERDAS Imagine the image was essentially exported for refining in ArcMAP. This was a good and simple intro into a program that will be used likely for more and more complex tasks throughout the remainder of the class.
Lets first get a glimpse of the Electromagnetic spectrum to start things off.
This is the spectrum looking at long waves on the right and short waves on the left and watching their transition from one side to the other. Happily we have our nice visible portion there in the center. What you need to understand here is that everything in our world is an emitter, reflecter, or absorber of energy falling somewhere on this spectrum. There are also things like the sun which emit energy in a continuous amount of energy across the entirety of the spectrum. All of the EMR sent out by the sun then interacts with our atmosphere or things it comes in contact with which it either reflects off of, is absorbed by, or is refracted from. Remote sensing cameras then get to absorb some of this EMR for us to view. From there we then get to manipulate the imagery we get into usable products like the below.
This is a very simplistic map which was built as an example of some basic processing from ERDAS Imagine. The image itself was first used in ERDAS to calculate the area of each category represented here. There are different classes of vegetation and land cover shown. You might also notice than when the remote sensing platform originally took the image there was something else we couldnt classify as ground cover... Clouds. Clouds occupy 507 acres of the image. from ERDAS Imagine the image was essentially exported for refining in ArcMAP. This was a good and simple intro into a program that will be used likely for more and more complex tasks throughout the remainder of the class.
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