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ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 KEEP THIS TEXT BOX this slide includes some ESRI fonts. when you save this presentation,

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Presentation on theme: "ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 KEEP THIS TEXT BOX this slide includes some ESRI fonts. when you save this presentation,"— Presentation transcript:

1 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 KEEP THIS TEXT BOX this slide includes some ESRI fonts. when you save this presentation, use File > Save As > Tools (upper right) > Save Options > Embed TrueType Fonts (all characters) this will allow vector maps created with common ESRI symbols to show on computers that do not have ESRI software loaded a a a a a a ESRM 304 Autumn 2009 Phil Hurvitz Modern Methods of Mapping, Navigation, and Analysis 1 of 42 To Infinity and Beyond!

2 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Mapping (again!??) GIS: its (much) more than just pretty maps Where yat? Everything you ever wanted to know about GPS* *but were afraid to ask Overview 2 of 42 Ad hoc, ad loc, and quid pro quo. So little time, so much to know

3 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 What is a map (remember from last class session?) What makes a map what it is? [Discussion] Mapping 3 of 42

4 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Why, in a modern/quantitative sense, are these not maps? What is a (not) map? 4 of 42 Archaeologists have discovered what they believe is the earliest known map, dating from almost 14,000 years ago. (in Spain) A Neo-Babylonian (Persian Period, circa 500 BCE) copy of an original map dating to the Sargonid Period, circa late eighth or seventh century BCE

5 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Why, in a modern/quantitative sense, are these not maps? Short answer: Lack of sufficient control/standardization of location of any particular feature (you could get lost easily) Lack of regular measurement framework (how will new features be placed on the map in the proper location? What is a (not) map? 5 of 42 Archaeologists have discovered what they believe is the earliest known map, dating from almost 14,000 years ago. (in Spain) A Neo-Babylonian (Persian Period, circa 500 BCE) copy of an original map dating to the Sargonid Period, circa late eighth or seventh century BCE

6 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 What really is a map (in a modern, quantitative sense)? Short answer: a series of controlled, carefully structured X, Y, Z, M coordinates Where X, Y, Z come from surveying (or some variation) in a standardized measurement framework, and matrix M comes from another measurement domain (e.g., soil type, forest stand species composition) What is a (not) map? 6 of 42 Dont get Lost in Space Use GPS and GIS!

7 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Mapping GIS: its more than just pretty maps (much more) Where yat? Everything you ever wanted to know about GPS Overview 7 of 42

8 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 What does GIS do? 1.[Fundamentally important]: stores XYZM coordinates in a standardized digital framework a land records database on steroids 2.Allows fine control over the display of these coordinates a mapping function 3.[Ultimately important]: allows geometric and logical processing of XYZM data to support decision-making GIS 8 of 42

9 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Why is GIS important in natural resource management? [Discussion] GIS 9 of 42

10 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Why is GIS important in natural resource management? It allows (relatively) easy, quantifiable, repeatable, and standardized measurements of the landscape and its features. GIS 10 of 42

11 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Mapping GIS: its more than just pretty maps (much more) Where yat? Everything you ever wanted to know about GPS Overview 11 of 42

12 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Measurement methods Problems with traditional natural resource location measuring systems Not always accurate or repeatable Requires careful measurement, training Requires careful note taking Can take large amounts of time Data storage issues Field notebooks Difficult-ish integration with other data (e.g., GIS, forest inventory) 12 of 42

13 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Measurement methods Q: How do we solve the problems with traditional measurement methods? A: GPS and GIS 13 of 42

14 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Manual measurements are not always accurate GPS brings accuracy 12 m accuracy for typical camping grade GPS equipment 1 m for mapping grade equipment Sub-centimeter accuracy for high-grade equipment Measurement of mountain building Measurement of plate tectonics 14 of 42

15 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Manual measurements are not always repeatable If you can get to the location (e.g., tree, inventory plot marker), your measurement will be repeatable within the precision of the equipment 15 of 42

16 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Requires careful measurement, training Equipment is self-recording Does not require external data recording Field notebooks are not necessary Does not require specialized training No mathematics 1 or 2 day training 16 of 42

17 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Requires careful note taking Equipment frequently contains digital data logger Locational and informational data are stored digitally in the data logger Field notebooks are not necessary 17 of 42

18 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Takes large amounts of time Measuring lines (e.g., roads, trails) is as fast as walking or driving Measuring polygons (e.g., stands, treatment units) is as fast as walking Measuring point locations can be as fast as stopping and pushing a few buttons 18 of 42

19 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Data storage issues Data are stored digitally; transferred digitally Data backup and transfer on magnetic, solid state, or optical disk (fast, cheap, easy) Standard computer equipment (CD, external hard drive, flash memory) How does GPS solve these problems? 19 of 42

20 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS solve these problems? Integration with other data (e.g., GIS, inventory) GPS data are already in digital format Easily used in association with other digital methods Inventory systems (e.g., FLIPS, SuperAce) GIS (direct export from GPS to GIS formats) 20 of 42

21 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 History of the GPS Cold War origins Advances in missile technology, 1940s-80s Advances in missile navigation systems (silo-to-silo attacks) Submarine missile launchers Missile launches need precise coordinates Surfaced submarines need fast locational fix Fire a missile quickly to avoid being seen Need for locational technology that is fast and precise 21 of 42

22 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 History of the GPS 22 of 42

23 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 History of the GPS Evolved out of EM/radio wave locational technologies (WWII onward) TRANSIT (US Navy, Polaris 1964) Public access, 1967 Doppler shift of satellite as it moved Stationary fix, ~every 40 min TIMATION I (USN, 1967) Coded signals Precise timing Ranging based on transit time of signal 23 of 42

24 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 History of the GPS Navigation Technology Program (USN, USAF, 1973) Evolved to NAVSTAR GPS Phase I ( ) Concept validation Prototype satellites 24 of 42

25 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 History of the GPS Navigation Technology Program (USN, USAF, 1973) Evolved to NAVSTAR GPS Phase II (1978) Full-scale development 4 satellites launched By 1985, 7 operational satellites, ~5 hrs coverage Current = 32 satellites Others? GLONASS: Russian Federation (1984-Present) EU? Japan? Commercial vendors? 25 of 42

26 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? Satellite signals Satellites send coded radio wave signals Signals are stamped with particular data: Time of signal generation Satellite ID number Radio waves are a form of EM radiation Light travels at 186,000 mi/s (in a vacuum) Time stamps on signals result in distance measurements 26 of 42

27 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? Distance = rate * time Radio waves are sent from orbiting satellites Time stamp on each signal marks the start of the wave Time of reception marks the end of the wave start: 0.00 s end: 0.06 s 12,000 mi 27 of 42

28 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? With the distance from 1 satellite we can locate our position on the surface of a sphere 28 of 42

29 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? With the distance from 2 satellites we can locate our position on the intersection of 2 spheres (a circle) 29 of 42

30 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? With the distance from 3 satellites we can locate our position on the intersection of 3 spheres (1 of 2 points) 30 of 42

31 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? With the distance from 4 satellites we can locate our position on the intersection of 4 spheres (1 point) 31 of 42

32 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 How does GPS work? The point is (hopfully) located on the surface of the earth 32 of 42

33 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 What are the benefits of GPS vs. manual survey? Summary: benefits of GPS over other methods Easy to learn Fast to use Automated data recording Requires less attention to detail Errors are not additive No math! 33 of 42

34 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Potential GPS error sources Satellite geometry Satellites that are closer result in less accurate measurements 34 of 42

35 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Potential GPS error sources Satellite geometry A large spread of satellites makes the most accurate measurements 35 of 42

36 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Potential GPS error sources Landscape features Natural & artificial features can intercept signals Mountains, valleys, hills, buildings, tree canopies, etc. 36 of 42

37 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Potential GPS error sources Multipath errors Natural & artificial features can reflect signals Multiple ghost signals can confound timing: which signal to trust? 37 of 42

38 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Equipment can fail, resulting in lost or corrupted data Equipment can be misconfigured, leading to lost or corrupted data, or in the best circumstance, correctable systematic error The DoD could go broke You could go broke (and not be able to buy a GPS unit) Other potential GPS problems 38 of 42

39 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Land measurement and navigation systems have evolved over time Throughout the modern history of measurement, standards have been critical Many different measurement frameworks exist Metes & bounds PLSS UTM State Plane … Conclusion 39 of 42

40 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 Different measurement methods exist Metes & bounds Plane surveying Geodetic surveying GPS Different data storage systems exist Maps Paper or electronic tabular records GIS Conclusion 40 of 42

41 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 No measurement framework, method, or storage system is perfect Different methods are the most appropriate in different situations Considerations: Functional requirements Cost Ease of use Institutional considerations Conclusion 41 of 42

42 ESRM 304: Environmental and Resource Assessment © Phil Hurvitz, 2009 The earth has music for those who listen. William Shakespeare To Infinity and Beyond 42 of 42


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