ERDAS 1: INTRODUCTION TO ERDAS IMAGINE GEO 420

Goals: Display raster image using panchromatic, normal & false color. Use zoom tool/buttons to properly display image and inquire cursor to identify pixel locations and digital numbers. Display image automatically scaled with DN’s stretched from 0-255, or with natural spectral variation. Use histogram to view spectral variability and frequency/proportion of DN’s within each class. 4. Perform a linear contrast stretch 5. Measure distances and areas within an image. 6. Create spatial and spectral profiles of an image.

1. Displaying an Image No stretch image View/Edit Image Metadata

Lanier.img - Landsat Thematic Mapper (TM) image that has 7 wavebands of information with 512 rows and columns of raster information. You have displayed a False Color Composite which sends Near Infrared (NIR) Light in TM Band 4 to the Red color gun, Red Light in TM Band 3 to the Green gun, and Green Light TM Band 2 to the Blue gun. Display Options settings - No Stretch – so it looks dark. Home > Metadata Icon and choose View/Edit Image Metadata - gives you all of the info Imagine has on this image (number of layers is 7 for TM, min and max DN values, the Measurement Units, and the Projection (if any), etc.

2. Inquire Cursor Utility

Google Earth Capabilities

3. Histograms Type of Image Enhancement: Contrast manipulation – contrast stretching of histogram distn

4. Stretching an image Swipe

5. Measurements

6. Spectral Profiles Band 1 = blue (high due to scattering) Band 2 = green Band 3 = red Band 4 = near infrared Band 6 = thermal

6. Spatial Profiles

Landsat 7 and TM & ETM+ Characteristics: Band Spectral Range(µm) Resolution(m) 1 .45 to .51 30 2 .525 to .605 30 .63 to .690 30 .75 to .90 30 1.55 to 1.75 30 7 2.09 to 2.35 30 10.40 to 12.5 (thermal) 60

NDVI