DCP GEOG 370 Lecture Outline

On March 25th, 2004, at the request of the instructor, Dr. Michael Buzzelli, I gave a guest lecture to the Geography 370(Introduction to Geographic Information Systems) course at the University of British Columbia. The primary topic was the Degree Confluence Project. Below is the outline I used for the lecture.

Dave Patton

1. Pre-Lecture
   • test browser, and internet connection to DCP website
   • test display of 'backup' webpages from CDROM(to be used in case internet connection(or DCP website) is unavailable)
   • test display of projection of PC screen
   • run through 'list of webpages' to get them into browser's cache
   • have the Composite World Map displayed on the screen
2. Introduction
   Introduction by the instructor, Dr. Michael Buzzelli
3. Dave Patton Introduction
   • self-employed computer-consultant, and have working in the computer field in various roles
   • some of my hobbies are outdoor-related, such as hiking, skiing, snowshoeing, and searching for edible mushrooms
   • a friend had a GPS receiver, and in spring 2001 I decided to get one
   • during my research about GPS receivers, I found the Degree Confluence Project website
   • the list of Degree Confluences for BC wasn't complete, and I volunteered to finish the work on the list
   • shortly after that, the project's founder asked for volunteers to help with some of the administrative work of the website, which is how I became Canadian Coordinator
   • after that, I also got involved with doing some of the website programming
4. The Degree Confluence Project
   • started in 1996, by Alex Jarrett, with the idea of using a GPS to see what would be located at the intersection of integer degrees of latitude and longitude
   • first confluence visit by Alex was to 43N 72W in New Hampshire, USA
   • Alex made a webpage about his visit, and over time he added more visits, and friends also made visits, and confluence.org was started, and keeps growing
   • the website was initially hosted for free by a friend of Alex, but since February, 2002 has been hosted at ibiblio, "the public's library and digital archive"
   • degree confluences
     • lines of latitude, or parallels(e.g. 49th parallel), run east-west, with the equator at 0 degrees latitude, and all other lines of latitude being parallel to the equator, ending with 90 degrees at the poles
     • lines of longitude, or meridians, run north-south from pole to pole, with the prime meridian, or 0 degrees longitude, running through Greenwich, England, and the other lines of longitude extending east and west to 180 degrees
     • for the DCP, a "degree confluence" is the intersection of an integer degree of latitude with an integer degree of longitude, such as 50 degrees north latitude and 123 degrees west longitude, or 50N 123W
     • FAQ #1.5 there are 64,442 of these degree confluences worldwide, with about 14,000 on land
     • the distance between degrees of latitude(parallels) is, for the purposes of the DCP, considered 'constant', ranging from 110.57km (68.71mi) at the equator, to 111.69km (69.40mi) between 89 degrees latitude and the poles
     • the distance between degrees of longitude(meridians) goes from 111.32km (69.17mi) at the equator (0 degrees latitude) to 1.95km (1.21mi) at 89 degrees latitude, and because the lines of longitude meet at the poles, the distance between degrees of longitude at the poles is zero
     • to deal with how this longitude convergance towards the poles affects the 'sampling of the world' based on degree confluences, we designate degree confluences as either primary or secondary
     • the Poles Problem section of our website explains this in more detail
     • we are working with locations on the (curved) earth - many people think of lines of lat/lon as "straight", because they are used to dealing with paper maps, which use a map projection
   • confluence visits
     • The goal of the project is to visit each of the latitude and longitude integer degree intersections in the world, creating an organized sampling of the world
     • FAQ 1.7 we have primary and secondary designations for confluences, but visits to both categories will be posted
     • Geodetic Datum Overview by Peter H. Dana
     • we use the WGS84 datum for the project
     • for the project's purposes, a visit consists on getting with 100 meteres of the WGS84 degree confluence, on the earth's surface, taking photos that meet our Photo Requirements and submiiting the photos and a narrative to the project's website
     • visits are categorized as successful or incomplete
     • incomplete visits(formerly "attempted" visits) can be due to problems with the visit photos, not getting within 100 meters, aerial 'visits', or datum problems
     • when visits are submitted to the website the assigned regional coordinator 'verifies' it before it is made active on the website
     • the 'verification' consists of administrative tasks to make sure the visit submission is ready to be made active
     • we use the honor system - we don't independantly verify if a person has been to the degree confluence
     • sometimes a "successful" visit gets changed to "incomplete" because of evidence such as the photo of the GPS coordinates, or information from a subsequent visit by someone else
   • website maps and data
     • we developed a symbol set for use on our maps to visually distinguish categories of confluences and their visit status
     • data used to develop our maps, such as Iceland all came from free sources
     • other free data was used to establish an approximate altitude for the confluence, which we show on the page for each confluence, such as for 65N 17W in Iceland
     • the confluence height data was also used to allow us to index some confluences that are on the water, such as those south of Iceland, or 48N 125W off the coast of Washington State
   • confluence page features
     • 51N 124W
       • site navigation menu along top of page
       • confluence navigation via the cardinal points around the globe in the upper left corner
       • information about the confluence on the left-hand side
       • links to various types of maps
       • link to the confluence page for the antipode 51S 56E, which is an unindexed secondary confluence
     • 50N 123W
       • has been visited, so has visit information, including the visitor name(s), the photos, and the narrative
     • 46N 71W #2
       • is the second visit, so it has a thumbnail photo and link to visit #1
       • has the narrative in both French and English
       • all visit narratives are available in English, but we have visits that have the narrative in Chinese, Dutch, French, German, Italian, Japanese, Portuguese, Russian, and Spanish
     • future plans
       • addition of a translate option
       • using the soon to be available worldwide satellite image data from NASA's JPL OnEarth project
     • use of "images" other than photos
       • I have used satellite images from NASA for some of my visits
       • I have used Landsat-7 satellite images for some of my visits
       • some people, such as Joseph Kerski, a geographer with the USGS, include a short movie clip, such as at 41N 102W #2
   • website features
     • the Country Index lists all the "countries" for which we have information, whether or not they have any degree confluences
     • each country, such as Canada has it's own page, which includes a link to the CIA World Factbook information page, and either a list of the regions in the country or a list of confluences
     • for countries with regions(e.g. provinces, states, territories) each region, such as British Columbia has it's own page, with a list of confluences
     • there is a Search page to allow searching for confluences or confluence visitors, and it also includes some 'confluence trivia' links
     • there is an Information page that serves as a central starting point to get to all the information about the project, including our Pressroom, which has information on articles and broadcasts about the project
     • the site is all run by volunteers, so there are minimal costs, but we do sell T-shirts, mugs and caps to help with costs such as domain registration
     • some confluence visitors have donated money to the project, and we have a nice Calendar which is available for free, but some people make donations if they use it
     • we show some statistics on the site's main page, and have a more complete Project Statistics page as well
     • as of mid-March 2004, the website traffic for the prior 12 month period was over 450 gigiabytes, with over 16.25 million pages being served
     • we don't consider the Degree Confluence Project to be a competition, which is why we don't 'keep score' of who has the most visits, but there are some notable confluence visitors
       • the people with the most Canadian confluence visits are Alan and Carolyn Fox, from Saskatchewan
       • their dog, Max, has made as many confluence visits as I have, with a better success rate!
       • Targ Parsons is the person with the second highest total of confluence visits, almost all of which are in China
       • the person with the most confluence visits is Captain Peter
   • other uses for the website
     • if you want to take a 'quick break' and go on a 'surprise vacation' for a few minutes, you can use the Random link on the confluence page to read about a random confluence visit from our database
     • even if you never plan to visit a degree confluence, the information on the website may be of interest, such as when planning a visit to a particular area, if there happen to be confluence visits nearby that provide some information about the area
5. GPS
   • the Global Positioning System consists of three parts
     1. the space segment: a group of 24+ satellites that orbit the earth every 12 hours
     2. the control segment: stations on the ground that make sure the satellites are working properly
     3. the user segment: receivers, which typically you hold in your hand or mount in your vehicle
   • the GPS system was built, and is maintained and controlled by the USA
   • there are other satellite-based systems being developed, such as EGNOS in Europe and GLONASS in Russia
   • when most people talk about GPS, they are actually referring to a GPS receiver, or GPSr
   • GPS receivers do just that - receive the signals from the Global Positioning System satellites - they do not 'send signals to the satellites', 'bounce signals off the satellites', or 'broadcast your position'
   • by using trilateration, the GPS receiver calculates it's position
     • the precise location of three or more known points are needed, which it gets because the precise positions of the GPS satellites in orbit are known, and broadcast in the GPS signals
     • the distance between the known points and the position of the GPS receiver is needed, which is calulated based on the delay of the GPS signal between being sent from the satellites and reaching the receiver
   • because GPS receivers can't receive signals "from below"(i.e. in the earth), the horizontal accuracy is better than the vertical accuracy
   • GPS signals used to be degraded for civilian use, resulting in an accuracy around 100 meters, but "Selective Availabilty" was turned off May 1, 2000
   • typical current-generation consumer GPS receivers have an accuracy of less than 15 meters, with survey-grade receivers having centimeter-level accuracy
   • GPS signals are also used for uses other than just finding location, such as in cellphone networks for precise timing
   • if you are going to buy a GPS receiver, the best thing is to get some knowledge first, so you have some idea of how you will want to use the receiver(e.g. antenna type/orientation), and whether or not you want a mapping GPS receiver
6. Other Topics
   • Geocaching
     • an adventure game for gps users, started in May, 2000
     • someone hides an object (called a cache), and others, using the provided clues, geographical coordinates and a GPS receiver, try to find it
     • the cache is often hidden, in a watertight plastic container, and contains a logbook, and typically some "items", and sometimes a disposable camera
     • people who find the cache make a notation in the logbook, remove one of the cache items and replace it with something else, and maybe take a photo
     • cache locations, clues, and finds are published on a website, such as navicache.com
     • the geocaching.com website is perhaps the largest geocaching website, but has some people upset due to it's commercial nature
   • GPS Drawing
     • Large-scale digital mark-making using GPS satellite navigation technology, started in November, 2000
     • using a GPS receiver to record a tracklog, a 'drawing' is recorded
     • the drawing can be done on land, on the water, or in the air
     • the main website is gpsdrawing.com
     • one example is The Brighton Elephant
   • "pointers and bounders"
     • there is a Yahoo group called BoundaryPoint which is a discussion list for "pointers and bounders"
     • "pointers and bounders" are those slightly strange individuals who are interested in finding, researching, photographing and discussing geopolitical boundary points, especially those of a tri-state or multipoint nature
     • discussions also include issues related to borders
     • Brian Butler has a website, The Corner Corner
     • The DCP has an incomplete confluence visit by Brian to 60N 102W, the junction of Manitoba, Northwest Territories, Nunavut, and Saskatchewan.