1. Support the spread of “good practice” in generating, managing, analysing and communicating spatial information Obtaining Remote Sensing Images By: J.Verplanke, ITC Unit: M11U02

2. Data selection criteria Spatial detail and temporal differentiation Acquisition (time of day / of year) Spatial coverage Temporal coverage Data size (download and storage)

3. Data selection criteria Spatial detail and temporal differentiation –Low resolution / multi-temporal –High resolution / single temporal –High resolution / multi-temporal

4. Data selection criteria Image resolution is often referred to as “pixel size” of the image. Source: Satellite Imaging Corporation

5. Data selection criteria Spatial detail and temporal differentiation Low resolution / multi-temporal Source: http://landsat.usgs.gov/gallery.php

6. Data selection criteria Spatial detail and temporal differentiation High resolution / single temporal

7. Data selection criteria Spatial detail and temporal differentiation High resolution / multi-temporal

8. Data selection criteria Acquisition (time of day / of year)

9. Data selection criteria Spatial coverage –There is a trade-off between spatial coverage and spatial resolution

10. Data selection criteria Temporal coverage There are over 10 million items in the UCSB SPOT Catalog between 1986 and 2009. The temporal coverage of the items is graphically shown by the histogram. Each green/yellow bar represents a year. The height of a bar reflects the number of items that overlap that time period. SPOT Source: Satellite Imaging Corporation

11. Data selection criteria Data size (download and storage): –Downloading and storing imagery requires significant hardware capacity. –Most imagery, when ordered, can be supplied by mail on DVD if data connections are insufficient (too slow) or unreliable to download.

12. Availability and cost Availability of imagery Cost versus resolution

13. Pre-processing imagery Example of atmospheric correction Source: Value Mine Limited – value-mine.com

14. Geometric correction of imagery Orthorectification of images: Source: Penn State Online Geospatial Education

15. Sources of imagery National (government) Commercial enterprises Online repositories

16. Sources of imagery