1 / 53

Earth from Space

Earth from Space. Geography 250 Unit1,2 Introduction and Brief History. Earth Rise Dec 24 th 1968 (while orbiting the moon) "the most influential environmental photograph ever taken”. Course Aims. Understand what we can learn about earth from data obtained from instruments in air or space

michael-stokes
Download Presentation

Earth from Space

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Earth from Space Geography 250 Unit1,2 Introduction and Brief History

  2. Earth Rise Dec 24th 1968 (while orbiting the moon) "the most influential environmental photograph ever taken”

  3. Course Aims • Understand what we can learn about earth from data obtained from instruments in air or space • To explore remotely sensed data such that you can select products that aid you in solving problems within the GIS environment • Understand images that you see in the news

  4. Earth from a Distance • More difficult for the flat earth society! • Earth as being visually conveyed • Uniqueness (so far!) • Water/Earth • Dynamic surfaces • Remote view as providing information to many people including geographers

  5. Remote Sensing • Remote: from a distance • In contrast to: In-situ - on site and in contact • Sensing: some type of detection - data are obtained and stored • Remote sensing “ the science, technology and art of obtaining information about objects from a distance”

  6. Remote sensing capabilities • Access to otherwise inaccessible areas • Antarctic, volcanoes, war zones, deep sea, disaster areas, eg Katrina, (flooding shown here) • View at a different scale • Patterns emerge not seen from the ground eg. archaeological sites and hemispheric meteorological data from satellites

  7. Remote sensing capabilities(Cont) • Information from wavelengths other than visible • We see a very narrow range of wavelengths

  8. Information from other wavelengths Wavelengths both outside of and within visible are assigned different colors such that the image can be readily interpreted This image shows sea surface temperature from AVHRR

  9. Other wavelengths A wildfire in Yellowstone shown in visible light (left) and thermal IR imaging (right)

  10. Remote sensing capabilities (Cont) • Cost effective for large areas • Aids in visualization

  11. Remote sensing capabilities (Cont) • Analysis over time • Air photos are commonly used for map updates • Images show sea surface height relative to an average sea surface height

  12. Geography • Geo/graphy = Earth/writing or Earth/description • Study of the distribution of physical and human phenomena, their interactions and the reasons for their location. • A study of where things are and why. • Hence remotely sensed data ‘fits’ into this area of study as does GIS

  13. Geographic Information Systems (GIS)  • Automated overlay/combination of types of data. • Technology used to answer questions such as: • Where is the best routing for a new power line, place for a new store, controlled forest fire burns, conservation area, emergency management • Software package such as ARCINFO • Geographic data: • Remotely Sensed data and analysis of these data • Maps • Surveys eg census data • Point measurements (at known locations using GPS)

  14. GIS http://www.wiley.com/college/strahler/0471480533/animations/ch03_animations/animation4.html

  15. Very early remote sensing Battle in 1297 Drawings were made from hill-tops, trees, ship masts etc

  16. Early remote sensing • 1859 French Photographer and Balloonist Gaspard Felix Tournachon, also known as Nadar Photo from a balloon anchored in Boston, made in 1860 (first photograph was in 1820s but cameras only became practical in the 1860s)

  17. Photography from Kites • Composite photo of part of San Francisco following the 1906 earthquake • Made from a camera on a kite

  18. The Bavarian Pigeon Corps 1903 Small light weight cameras were attached to the birds and a timer was set to take pictures ever 30 seconds as it flew. (Birds had been used for some time for messages)

  19. WWI 1913 - 1918 Graflex camera used in WWI ‘There were several aircraft used for aerial reconnaissance throughout the war. First made of wood and then metal, the aircraft was the focus of intense development. At the same time camera systems and techniques for measuring and identifying features on the ground were being developed. These interpretation and measurement techniques, and the men and women who practiced them during war time, continued after the war and applied them to other areas such as forestry and agriculture.’

  20. Air photos played a major role in the war starting in 1915 Role of interpreters: Detectives Use of clues: Convergence of information (Data fusion) Repeat photographs

  21. Non-military applications • Photogrammetry evolved: technology involved in making accurate measurements of distances and heights from maps • Uses: Topographic maps, forest inventory (amount and type of trees), geologic mapping, agricultural statistics (who was growing what) • Canada as mounting a comprehensive air photo campaign • 1935 American Society of Photogrammetry formed (now also remote sensing) importance of this???

  22. World War II (start 1939) • Germans started out in the lead with the recognition of the importance of remote sensing. • Had images of key sites in other countries • Also very good maps in the Baedeker guides and used them in the invasion of Norway and Britain, term “Baedeker raids” • 'We shall go out and bomb every building in Britain marked with three stars in the Baedeker Guide.' - Baron Gustav Braun von Sturm, 24 April 1942

  23. World War II RAF air photo interpretation • ‘A group of British and American air photo interpreters work at the large Medmenham interpretation center located near London, England. Air photo interpretation developed into a top priority program by 1943. Air photos were used to confirm or deny reports from spies in Europe

  24. WWII developments • New films – color infrared, able to tell vegetation from cloth painted green • Radar- new wavelength, ‘see’ in the dark and in fog

  25. Post-WWII • 1950 – 1970 • Continuing world tension, hence development • Many qualified photo interpreters with ideas of the usefulness of technology • Color infrared declassified • Also multispectral imagery • Thermal Infrared • Side looking airborne radar

  26. Color infrared AKA Near Infrared • Reflected energy at wavelengths a little longer than what we can see (0.7 – 1.5 micrometers) Photography captures the green, red, and near-infrared energy, which is displayed in a false-color form Color-infrared images are particularly useful for analysis of vegetation cover. Active vegetation appears bright red and pink in color-infrared photographs. Other materials--bare soil, pavement, water--are depicted in green and blue colors. http://www.ars.usda.gov/Main/docs.htm?docid=8829 Study example: www.emporia.edu/nasa/epscor/ft_leav/epscor.htm

  27. Thermal Infrared The waste heat from electrical generating stations is transferred to cooling water obtained from local water bodies such as a river, lake, or ocean. The water is subsequently returned to the water body with a temperature higher than the ambient water temperature. A thermal plume from a cooling station Thermal infrared (thermal IR) is emitted energy, range 5.6micrometre to 1.0 cm

  28. Airborne Radar Sensor emits microwaves and then receives microwaves that are returned to the sensor Hence can image through fog! And darkness Brazilian rain forest

  29. Continued military • Higher resolution • Flights by the U-2 an ‘untouchable’ aircraft for four years until 1960 when it was shot down (very embarrassing for the US). • Space as the answer! • Corona as the first operational space photo reconnaissance satellite (1960 – 1972) Corona image of the Pentagon Corona as secret until 1992

  30. U-2 with Side Looking Airborne Radar (SLAR)

  31. Information from the U-2 program • Photo of a Soviet missile site in Cuba

  32. Sputnik • Oct 1957 - First satellite put into orbit around Earth! (lasted 3 months) • USSR • Fear – response was the ‘Space Race’ • http://www.sputnikmania.com/

  33. Space as the answer! Corona image of the Pentagon Corona as secret until 1992

  34. Corona satellite film recovery sequence

  35. Non-military space imaging • Weather satellite: TIROS-1 Before this the only information was from the ground and weather ships

  36. Earth remote sensing an offshoot of moon exploration 1968 Apollo 8 lunar orbit 1969: Apollo 11 lunar landing Interest in space coincided with growing concern about Earth

  37. Satellites and earth observation 1972 - 1986 • Landsat 1972 and onwards • Growing concern about human impact • NASA program First Landsat images

  38. Landsat images of the Philippines

  39. Thematic Mapper • Instrument on some of the later Landsat satellites • Bands (segments of the spectrum) are combined • These are known as multispectral images • Called a thematic mapper because the data can be used to map specific things like vegetation types, minerals • Earlier version of the instrument was known as a multispectral scanner (MSS)

  40. Advanced Very High resolution Radiometer (AVHRR) • Another major earth observation program (initially intended for atmospheric information) • NOAA 1.1 km resolution imagery • Visible and near IR Vegetation using the near IR bands

  41. Total Ozone Mapping Spectometer (TOMS) Measurement of the ozone hole over the Antarctic (observations started in 1978?)

  42. Radarsat • Canada/USA satellite for earth observation, launched in 1995 • With time countries other than the US have become involved in remote sensing, Canada, Europe, Japan, Brazil etc

  43. Photographs vs digital images • Photographs: Light falling on a sensitive surface (film) • Digital images: pixels, each of which has a numerical value • Image processing initially lagged behind acquisition • Digital images are replacing photographs • Why • Amount of information • Computer analysis

  44. Digital images • Like mosaics • Resolution in part a function of pixel (picture element) size • Each pixel can have a value from 0 - 254

  45. Orthophotos (a type of photo) Used for watershed and other land use planning, many uses Photographs have been geometrically corrected ("orthorectified") so the scale of the photograph is uniform Hence the photo can be considered equivalent to a map Ortho images are often mosaics of orthophotos These can be readily used in GIS

  46. Beyond NASA and NOAA: Commercial programs • IKONOS in 1999 (Space Imaging Inc/USA) • One-meter resolution • Multispectral and panchromatic (like b/w film) • EROS A1 in 2000 (ImageSat/Israel&USA) • Rapidly followed by others … increasing spatial resolution • List: http://en.wikipedia.org/wiki/List_of_Earth_observation_satellites

  47. Remote Sensing and GIS • Complementary technologies • Talk to Ron Raty if you are interested in GIS • Remotely sensed data are used in GIS systems in planning and also for Earth Science research • This course focuses on remote sensing and what we can learn about Earth from various types of imagery.

  48. Complementary nature • Remotely sensed data: rich source of data • GIS powerful tool for analysis and display • “Integrating these technologies has been a challenge” • Only in late 1990s was it possible for GIS systems to ingest larger raster images • Geomatics: newfield that includes surveying, use of GIS, GPS, remote sensing, cartography (term coined in about 1970)

  49. Global Positioning System (GPS) • Two part system: • Satellites orbiting earth • Handheld receivers

More Related