{"id":1243,"date":"2020-07-16T14:40:07","date_gmt":"2020-07-16T14:40:07","guid":{"rendered":"http:\/\/wordpress.library.illinois.edu\/max\/?page_id=1243"},"modified":"2025-08-22T20:38:24","modified_gmt":"2025-08-22T20:38:24","slug":"air-photo-books-new","status":"publish","type":"page","link":"https:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-books-new\/","title":{"rendered":"Air Photo Interpretation"},"content":{"rendered":"<ul class=\"nav nav-tabs\">\n<li class=\"active\"><a href=\"http:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-books-new\/\">Interpretation<\/a><\/li>\n<li><a href=\"http:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-coverage-new\/\">Coverage<\/a><\/li>\n<li><a href=\"http:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-indexes\/\">Indexes<\/a><\/li>\n<li><a href=\"http:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-scanning-new\/\">Scanning<\/a><\/li>\n<li><a href=\"http:\/\/wordpress.library.illinois.edu\/max\/collections\/air-photos-new\/air-photo-web-resources\/\/\">Web Resources<\/a><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-2742 size-medium\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Topo-with-air-photo-248x300.jpg\" alt=\"United States Geological Survey 1:24,000-scale Lake Calumet Quadrangle topographic map partially overlaid with a black-and-white 1:40,000-scale aerial photograph showing the same geographical area as the topographic map.\" width=\"248\" height=\"300\" srcset=\"https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Topo-with-air-photo-248x300.jpg 248w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Topo-with-air-photo-845x1024.jpg 845w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Topo-with-air-photo-768x930.jpg 768w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Topo-with-air-photo.jpg 971w\" sizes=\"auto, (max-width: 248px) 100vw, 248px\" \/>Aerial photograph interpretation and use is different from map reading. Unlike most maps, aerial photographs usually do not have any words or labels on them.<\/p>\n<p>Known locations sometimes are difficult to find without labels so using a reference map side-by-side with aerial photographs is always helpful.<\/p>\n<p>The passage of time can play a role in being able to positively identify a site. It can be difficult to identify a location that 65 years ago was an open field when today it is a busy urban intersection. Consider working backwards from the present to the desired time. Find the desired location on a photograph that shows a familiar landscape then view photos of the same area in reverse chronological order, identifying features that change or disappear as time is unwound while staying geographically tethered.<\/p>\n<p>&nbsp;<\/p>\n<p>Features on air photos need to be identified using clues given by different characteristics: size (relative and actual); shape; shadows; pattern; tone (shades of gray) and color; visual texture; and site context or association. These important aspects are briefly described in a <a href=\"https:\/\/en.wikipedia.org\/wiki\/Aerial_photographic_and_satellite_image_interpretation\">Wikipedia article on interpretation<\/a>.<\/p>\n<div class=\"row\">\n<div class=\"col-md-4\">\n<figure id=\"attachment_1867\" aria-describedby=\"caption-attachment-1867\" style=\"width: 226px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-1867\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Relative-Size-Tracks-226x300.jpg\" alt=\"Portion of a 2005 air photo of Urbana, IL, highlighting tracks\" width=\"226\" height=\"300\" srcset=\"https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Relative-Size-Tracks-226x300.jpg 226w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Relative-Size-Tracks-770x1024.jpg 770w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Relative-Size-Tracks-768x1021.jpg 768w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Relative-Size-Tracks.jpg 1009w\" sizes=\"auto, (max-width: 226px) 100vw, 226px\" \/><figcaption id=\"caption-attachment-1867\" class=\"wp-caption-text\"><i> <strong>Relative size<\/strong> can be used to identify features. The track circled in yellow at the top of the photograph is the Champaign County Fair Grounds race track. The track circled at the bottom is the track and football field of Urbana High School.<\/i><\/figcaption><\/figure>\n<\/div>\n<div class=\"col-md-4\">\n<figure id=\"attachment_3031\" aria-describedby=\"caption-attachment-3031\" style=\"width: 278px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3031 size-medium\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon-278x300.jpg\" alt=\"Portion of a black-and-white aerial photograph of Gibson City, Illinois, centered on the Harvest Moon Drive-In movie theater.\" width=\"278\" height=\"300\" srcset=\"https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon-278x300.jpg 278w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon-950x1024.jpg 950w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon-768x828.jpg 768w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon-1425x1536.jpg 1425w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Shape-Harvest-Moon.jpg 1685w\" sizes=\"auto, (max-width: 278px) 100vw, 278px\" \/><figcaption id=\"caption-attachment-3031\" class=\"wp-caption-text\"><i><strong>Shape<\/strong> helps identify features. The bright white, fan-shaped object in the center of the photo is the Harvest Moon Drive-In in Gibson City. At the time of the photo, the theater had only one screen, between the fan of parking spots and the north-south road (Illinois 47).<\/i><\/figcaption><\/figure>\n<\/div>\n<div class=\"col-md-4\">\n<figure id=\"attachment_3032\" aria-describedby=\"caption-attachment-3032\" style=\"width: 194px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3032 size-medium\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-194x300.jpg\" alt=\"Portion of an aerial photograph of rural Champaign County, Illinois.\" width=\"194\" height=\"300\" srcset=\"https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-194x300.jpg 194w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-664x1024.jpg 664w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-768x1185.jpg 768w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-995x1536.jpg 995w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County-1327x2048.jpg 1327w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Tone-Champaign-County.jpg 1646w\" sizes=\"auto, (max-width: 194px) 100vw, 194px\" \/><figcaption id=\"caption-attachment-3032\" class=\"wp-caption-text\"><i><strong>Tone<\/strong>, differences in shades of grey or color, can indicate a number of different qualities. In this photo of a portion of Champaign County south Champaign-Urbana, darker rectangles are probably a different kind of crop than lighter rectangles, and darker irregular shapes indicate soils with a higher moisture content than that adjoining lighter irregular shapes.<\/i><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_3033\" aria-describedby=\"caption-attachment-3033\" style=\"width: 816px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3033\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-300x194.jpg\" alt=\"Portion of an aerial photography centered on the southern portion of the University of Illinois Urbana-Champaign campus.\" width=\"816\" height=\"528\" srcset=\"https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-300x194.jpg 300w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-1024x664.jpg 1024w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-768x498.jpg 768w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-1536x995.jpg 1536w, https:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/09\/Pattern-South-Campus-2048x1327.jpg 2048w\" sizes=\"auto, (max-width: 816px) 100vw, 816px\" \/><figcaption id=\"caption-attachment-3033\" class=\"wp-caption-text\"><i><strong> Patterns<\/strong> assist in identifying different features on this photograph of South Campus. There are two cemeteries, parking lots, a small golf course, and different kinds of crops.<\/i><\/figcaption><\/figure>\n<h2>Photo Orientation<\/h2>\n<div style=\"float: right\">\n<figure id=\"attachment_1872\" aria-describedby=\"caption-attachment-1872\" style=\"width: 594px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-1872\" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Photo-Orientation.jpg\" alt=\"A pair of air photos demonstrating orientation\" width=\"594\" height=\"380\" \/><figcaption id=\"caption-attachment-1872\" class=\"wp-caption-text\"><i>Air photos of Champaign showing flight line-driven orientation. The photo on the left, from 1940, has identification information, marked in orange, on the west edge while the photo on the right, from 2005, has identification on the north edge.<\/i><\/figcaption><\/figure>\n<\/div>\n<p>Knowing the direction of the flight lines will help identify the north edge of Illinois aerial photographs. Do not assume that the identifying information is on the north, and thus right reading.<br \/>\nPhotographs from Illinois statewide sets (1988-2005), all flown with north-south flight lines, always have identifying information such as photo number, scale, and date of flight on the north edge of the photograph.<br \/>\nCounty sets (pre-1988) may have flight lines that run north-south or that run east\/west. North-south flight lines will have identifying information on the north edge while east\/west oriented sets will have identifying information on the west edge of the photographs.<\/p>\n<h2>Air Photo Overlaps<\/h2>\n<div style=\"float: right\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-823 \" src=\"http:\/\/wordpress.library.illinois.edu\/max\/wp-content\/uploads\/sites\/37\/2020\/07\/Air-Photo-Overlaps.jpg\" alt=\"Aerial photographs, as shown in this diagram, have substantial overlap within flight lines and, to a lesser extent, between flight lines.\" width=\"487\" height=\"269\" \/><\/div>\n<p>An essential component of aerial photography production is the overlapping coverage of adjoining photographs. Generally, the overlap within a flight line (the forward overlap) is approximately 60% wihle the overlap between photographs in adjoining flight lines (the lateral overlap) is approximately 30%. These overlaps cause features to be photographed multiple times from slightly different angles. These offset images, either 2 separate photographs (a stereopair) or a pair of photographs printed side-by-side) can be viewed through stereoscopes to give the illusion of heights or depths.<\/p>\n<p>A few small pocket stereoscopes and a larger mirror stereoscope are available for use at the Map Library\u2019s circulation desk.<\/p>\n<h2 id=\"Air_Photo_Books\">Books About Air Photo Interpretation<\/h2>\n<p>Quick Link<br \/>\n<a href=\"https:\/\/www.library.illinois.edu\/max\/collections\/remote-sensing-new\/remote-sensing-books-journals\/\">Remote Sensing Books &amp; Journals<\/a><\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/gpjosq\/alma99759615312205899\">Aerial Photography and Image Interpretation<\/a> by David P. Paine and James D. Kiser (2012)<br \/>\n<a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/1n2ls18\/alma99682619712205899\">E-book<\/a><\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/gpjosq\/alma99788067612205899\">Remote Sensing and Image Interpretation<\/a> by Thomas M. Lillesand, Ralph W. Kiefer, and Jonathan W. Chipman (2015)<\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/1n2ls18\/alma99932693612205899\">Small-Format Aerial Photography: Principles, Techniques, and Geoscience Applications<\/a>\u00a0 by James S. Aber and others (2019) (E-book)<\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/gpjosq\/alma99798439812205899\">Barnstorming the Prairies: How Aerial Vision Shaped the Midwest<\/a> by Jason Weems (2015)<br \/>\n<a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/gpjosq\/alma99906654012205899\">E-book<\/a><\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/1n2ls18\/alma99336285512205899\">Fundamentals of Remote Sensing and Airphoto Interpretation<\/a>\u00a0 by Thomas Eugene Avery and Graydon Lennis Berlin (1992)<\/p>\n<p><a href=\"https:\/\/i-share-uiu.primo.exlibrisgroup.com\/permalink\/01CARLI_UIU\/1n2ls18\/alma99339933012205899\">Basic Photo Interpretation<\/a> by Michael E. Rasher and Wayne Weaver, USDA Soil Conservation Service (1990)<br \/>\nText and accompanying set of practice photos created as instructional materials for the Soil Conservation Service<\/p>\n<h2>Online Air Photo Interpretation Resources<\/h2>\n<p><a href=\"https:\/\/natural-resources.canada.ca\/maps-tools-publications\/satellite-elevation-air-photos\/introduction-air-photo-interpretation\"> Introduction to Air Photo Interpretation<\/a><br \/>\nClear explanation of characteristics examined when interpreting air photos from Natural Resources Canada<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Interpretation Coverage Indexes Scanning Web Resources Aerial photograph interpretation and use is different from map reading. Unlike most maps, aerial photographs usually do not have any words or labels on them. Known locations sometimes are difficult to find without labels so using a reference map side-by-side with aerial photographs is always helpful. The passage of [&hellip;]<\/p>\n","protected":false},"author":90,"featured_media":0,"parent":1262,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-1243","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/pages\/1243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/users\/90"}],"replies":[{"embeddable":true,"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/comments?post=1243"}],"version-history":[{"count":20,"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/pages\/1243\/revisions"}],"predecessor-version":[{"id":4037,"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/pages\/1243\/revisions\/4037"}],"up":[{"embeddable":true,"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/pages\/1262"}],"wp:attachment":[{"href":"https:\/\/wordpress.library.illinois.edu\/max\/wp-json\/wp\/v2\/media?parent=1243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}