PRINCIPLES OF PHOTO INTERPRETATION

Transcription

1 PRINCIPLES OF PHOTO INTERPRETATION Photo Interpretation the act of examining photographic images for the purpose of identifying objects and judging their significance an art more than a science Recognition Elements seven Principles of Photo Interpretation tools used by photo interpreters skilled interpreter makes inferences based on the synthesis of a few or several Principles of P.I.

2 Photo interpretation requires some training and experience with conditions on the ground to be most effective. The accuracy of the mapping results can be quite variable depending on the skill level of the interpreter. The photo interpreter uses several recognition factors and most importantly, human reasoning to pull all of the clues together when making interpretation decisions

3 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION/SITE TONE (OR COLOR) These are the seven PI recognition elements or principles. A trained interpreter uses PI principles intuitively and combines them into a reasoning process that concludes in the object identification or the delineation of stand type boundaries. In some cases, one or two of the recognition elements will be more heavily relied on in the interpretation decision, depending on the photography and the environment under study.

4 PI Recognition Features SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR)

5 SIZE & SHAPE Maine Forest Practices Act Category 1 clearcuts (<35 acres in 1991) with 250 ft. forest separation zone

6 Unharvested Category 1 Clearcut - Separation Zone Harvest in Cat.1 FPA Separation Zone by 2004 Sader et al. 2005, J. Forestry

7 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR)

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10 SHAPE AND ASSOCIATION Bog and Hay Field

11 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR)

12 SHADOWS Spruce Trees- Pyramidal or tapered shape of shadow in fields - UM Campus at Park St. and Rangley Road

13 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR)

14 TEXTURE Mixed Forest mottled Older natural forest coarser texture Softwood Plantation, even-aged - smooth

15 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION Spaghetti roads of a heavy harvest TONE (OR COLOR) River meander scars and oxbows

16 USGS DOQs - So. ME 1998 New subdivision 2003 New clearing here

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18 PATTERN Hay Fields Angular Trailer Park regular spacing and orientation Roads linear or curvi-linear

19 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR)

20 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION/SITE TONE (OR COLOR)

21 Association- What relationship do the circular objects in the center have with the facility on the right center??

22 SHAPE AND ASSOCIATION Bog and Hay Field

23 Association/Site Conditions Topographic or soil-site relationships Black Spruce and tamarack (larch) in bogs Red maple swamps Hardwoods on upper slopes, spruce-fir in the valleys

24 PRINCIPLES OF PHOTO INTERPRETATION SIZE SHAPE SHADOW TEXTURE PATTERN ASSOCIATION TONE (OR COLOR) tone / color differences make all other recognition elements possible Learn to interpret objects on different film types understanding albedo / spectral signatures of objects

25 BW Panchromatic tone variation Color Infrared color variation

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31 LAND COVER AND LAND USE Land Cover type of feature physically present on the surface e.g. crops, forest, roads, urban features, etc. Land Use refers to the human employment of the land and its features e.g. residential, commercial, industrial, agriculture (crop, fallow, pasture), forest management, park / preserve, etc.

32 LAND COVER AND LAND USE example: land use: single-family residential land cover: roofs pavement grass trees

33 LAND COVER AND LAND USE * definitions of land cover and land use categories depends on a particular application, scale of analysis the classification scheme example: land use: single-family residential land cover: roofs pavement grass trees

34 LAND COVER AND LAND USE Land Cover / Land Use Classification e.g. USGS System a hierarchical system levels of increasing detail choose data types (layers), scale, and appropriate level of classification for a particular application identify classification scheme use of GIS as a classification and mapping tool

35 e.g. USGS System a hierarchical system levels of increasing detail

36 choose data types (layers), scale, and appropriate level of classification for a particular application

37 LAND COVER AND LAND USE use of Geographic Information System (GIS) Tools construction of a spatial database information layers input to database this information often comes from remotely sensed data (e.g. soils, forest cover type, road network, political / biological / property boundaries, etc.) use of overlay and analysis techniques query to answer your research / application questions

38 LAND COVER AND LAND USE