Spatial Enhancement

Lab Objectives:

By the end of this lab, students should be able to:
1. Download and import satellite imagery
2. Perform spatial enhancements in ArcMap and ERDAS
3. Utilize the Fourier Transformation function

The beginning of this lab (Exercise 1) focused on the process of acquiring satellite data. USGS Earth Explorer was used to identify correct imagery. The imagery could be downloaded and extracted, and then the imagery could be converted to the correct format and reprojected to the correct coordinate system. If needed, preprocessing (like image subsetting and image enhancement) could be conducted as well.

In ERDAS, Exercise 2 focused on importing data, changing the format from TIFF to IMG (using the batch option for multiple files), and creating a multispectral image from multiple panchromatic files using the layer stack tool.

Exercise 3 focused on spatial/image enhancements. In ERDAS, basic low and high pass filters were used to improve images (using the convolution tool). In ArcMap other filters were used, specifically focal statistics using mean and range to improve images.

Exercise 4 focused on image enhancements in ERDAS. An image of the Pensacola area was used, and there was a lot of striping in the image. Fourier transformation, using the wedge tool and the low pass tool, was utilized on this striped image. This removed much of the striping in the image. The convolution filter, using the 3x3 Sharpen Kernel, was used to sharpen the image. At the end of Exercise 4, I used Fourier transformation and the convolution filter again to remove even more of the striping and increase the sharpness. I used this final image to create a map.