Lesson 7: Answers/hints for exercises

  1. For each of the following areas of application, describe a situation for which real-time knowledge of location or easy collection of location-based data would be useful.

  2.  
    1. A highway towing service
      From a point of dispatch, real-time knowledge of locations of trucks would facilitate efficient assignments for pickup of disabled vehicles

    2.  
    3. A corporate farming operation, comprised of several dozen plots of land and managed through use of computer data bases.
      Data collected using GPS methods can be used to identify regions of soil various soil characteristics, undesirable vegetation, etc.

    4.  
    5. A visual record of all trees in a large park that meet certain specifications, e.g. size, health, species.
      GPS data collection methods can be used record accurately and quickly locations and other characteristics of the trees

     

  3. Describe three examples, other than those cited in Exercise 2, of potential applications for GPS. These will be applications using spatial data. Describe the attributes that are associated with location.
     
    Examples:
    • Fire-fighting: A helicopter with a GPS receiver can fly the perimeter of a large brush fire and record data that can be processed quickly to produce an illustration showing an outline of the burning region. Successive images show the manner in which the burning area is expanding, thus facilitating decisions about deployment of resources. The spatial data includes latitude, longitude, and is assumed to mark the boundary of the burning area
       
    • Monitoring land motion: Highly accurate GPS methods can used record data near fault lines, e.g. near Los Angeles in the San Fernando Valley. Receivers are on semi-permanent mountings near the fault lines. The spatial data includes latitude, longitude, altitude, identification of the receiver.
       
    • Rescue: Persons lost in unmarked territory or stranded in a disabled vehicle can send by radio their location as determined by a GPS receiver. The spatial data includes latitude, longitude and landmarks nearby.

     
  4. Go to WWW site Real time display of satellite orbits, including GPS satellites, and determine the orbits of some of the GPS satellites. You will see that these satellites are not geo-synchronous, but their plane of orbit makes a large angle with the equatorial plane. Assuming that this angle is the same for all satellites, examine the illustration of orbits at the site and estimate the angle.
     
    See Lesson 8.
     

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Materials developed by-
Prof. Wm. Rundberg
College of San Mateo
1700 West Hillsdale Blvd
San Mateo, Ca. 94402
650.574.6258