Module 3: Introduction to ERDAS Imagine

    In this week's lab, I learned about ERDAS Imagine and some of its capabilities. Most of part A was spent orienting myself to the feature and functions with ERDAS Imagine. I have not used this program before, so it was all very new to me. The navigation of images was somewhat similar to ArcGIS Pro but there were a few minor differences. I was able to follow the lab instructions for the most part. Once I got to the tm_subset creation and updated the area values, I did have an issue saving the tm_subset with the updated attributes. It does not seem like ERDAS Imagine likes to overwrite files. I ended up having to repeat the steps and create a new tm_subset. This time I elected to remove the image and save it when the pop up window appeared. This seemed to avoid the overwriting issue that I had initially. I then created a map in ArcGIS that displayed the tm_subset file created in ERDAS imagine, and it listed the area values calculated. Below is a map of the tm_subset file that I created.

    In part B of the lab, I explored the information stored in the metadata windows in ERDAS Imagine for a multispectral image. After exploring the metadata, I opened four view windows and compared four images with different spatial resolutions. The images with higher resolutions allowed me to see cars or groups of cars in a parking lot, but for the images with lower resolution, I was not able to distinguish the cars in the parking lot. Objects smaller than the pixel size of the image are not distinguishable. Next, I looked at four images with different radiometric resolutions and compared their appearance based on their resolution. As the radiometric resolution increased, the detail of the images became more and more apparent. Other resolution considerations include temporal and spectral resolution which deal with the time between images and the range of wavelengths/bands of EMR collected, respectively. Last, I used ERDAS to calculate the percent area of each soil type, and I learned how to select soil types based on criteria. The criteria function worked similarly to the select by attributes function in ArcGIS Pro. Once I selected the areas with higher erosion potential, I inverted the selection and hid the unwanted areas.