3. Cells - Absolute Values In this instance, the value of the cell represents the value of the phenomenon of interest, e.g. the elevation at that pixel location.

4. Flood Assessment Landsat TM (SWIR, bands 7-4-2)

5. Remember that the notions of small and large are reversed from our conventional thinking when we talk about scale  large scale refers to looking at a smaller area in detail. Here are some scale guidelines: –Large scale  1:400 to 1:50,000 –Intermediate scale  1:50,000 to 1:250,000 –Small scale  1:250,000 and beyond General Classification of Scale

6. Transverse Mercator Projection applied to each 6 o zone to minimize distortion UTM Zone Projection Central meridian Transverse Mercator: A cylindrical projection Standard lines

7. Geodetic Datums

8. Digital Image Processing: Image Enhancement

9. Contrast Enhancement example: A linear stretch is one of the most common types of contrast enhancement Minimum BV is remapped to 0 Maximum BV is remapped to 255 0255127 0255 60108158

10. The sky is blue because of Rayleigh Scattering. Shorter wavelengths (i.e. blue) of the visible spectrum are scattered more than longer visible wavelengths. So why isn’t the sky indigo or violet?

11. Rayleigh Scattering Short wavelengths are scattered by this mechanism more than long wavelengths. R O Y G B I V Short λ Long λ

12. Vector data County borders within a state

13. + + + + 1 point = 1 cell What problems do we have here? 2 points in a pixel Point on a border Raster Data Model - Points

14. Detecting Stress In Crops Continuous features: vector or raster? 3 2 3 1 2 1 Improper Seeding Water Stress Pipe Irrigation Center Pivot Irrigation Frost Damage 3

15. Shape Differences in forms of symbols Options: – abstract (e.g circle, square) –iconographic (e.g. airplane, flag, schoolhouse) Caution: too many different shapes can get very busy and difficult for the map reader to discriminate OrdinalRatioNominal Bad  Good Utility

16. Rules for Assigning Cell Values Cell values can be assigned to cells accorded to some set of rules, and selecting those rules differently can also effect the representation of features:

17. Satellite Imagery Described by five resolutions –Spatial resolution: area on ground represented by each pixel Advanced Very High Resolution Radiometer (AVHRR) – 1 km Landsat - 30m SPOT – 2.5m - 20m / 2.5m - 10m IKONOS - 1m/4m –Temporal resolution: how often a satellite obtains imagery of a particular area –Spectral resolution: specific wavelength intervals in the electromagnetic spectrum captured by each sensor –Radiometric Resolution: number of possible data values reportable by each sensor (how sensitive the sensor is to changes in brightness of objects that it views) –View angle resolution: the number of angles at which the ground objects are recorded by the sensor.

18. Question #23 1.In the following diagram of vector data, what is the Right polygon for arc 8? a.A b.B c.C d.D e.E B C D E 1 2 3 4 5 6 7 8 9

19. Question #24 1.Which 2 bands are most crucial to differentiate between Red Sand and Pinewoods? a.Bands 1 and 2. b.Bands 1 and 4. c.Bands 2 and 5. d.Bands 3 and 4.