Maps and GIS s on the Internet CS 128 ES

Maps and GIS’s on the Internet CS 128/ES 228 - Lecture 14 b 1

Fundamental Questions n Who has the maps? n Who has the data? n Who does the computation? CS 128/ES 228 - Lecture 14 b 2

The simplest model n Post a map n n No different than posting a photo of your pet. Post a series of linked maps n No different that posting a photo album of your pets. Some Dull Maps CS 128/ES 228 - Lecture 14 b 3

A More Sophisticated Model n Computer scientists often speak of a clientserver model. n In this model, one computer (the server) answers questions posed by another (the client) CS 128/ES 228 - Lecture 14 b 4

Examples of Client-Server n Google n Amazon. com n Actually, most web sites 3 D map of world wide web from www. opte. org CS 128/ES 228 - Lecture 14 b 5

A Client-Server GIS n Zillow – A Real Estate GIS At first Zillow just connected home locations to the local tax rolls so that valuations became known n Then it combined with map servers to display by neighborhood n Now it is branching into the buy-sell arena n Zillow CS 128/ES 228 - Lecture 14 b 6

Limitations of Zillow Not all areas well mapped n Geocoding is imperfect n Tax rolls are inconsistent n Zillow does NO computation besides map focus CS 128/ES 228 - Lecture 14 b 7

Servers that “compute” n Mapquest will produce a page for you that has never been viewed by anyone else in the history of the world! CS 128/ES 228 - Lecture 14 b 8

GMaps Pedometer Draw your running routes View it! CS 128/ES 228 - Lecture 14 b 9

Arc. View IMS § Internet map server connected to Arc software § Capabilities § Deliver dynamic maps (and DATA) through the web § Restrict user interface to something more appropriate than Arc. View § Bring modern web technology into GIS world CS 128/ES 228 - Lecture 14 b 10

Example 1 – Reuters Alert. Net Series of GIS layers (world-wide) connected to an index (menu) featuring areas of interest to humanitarian/relief workers/agencies Alert. Net CS 128/ES 228 - Lecture 14 b 11

Greenwood County n Classic ARC-like interface n Visual BASIC. Net back end (also uses Active. X) n “Lightweight” GIS – designed to load and compute quickly Greenwood CS 128/ES 228 - Lecture 14 b 12

San Francisco Prospector n Business information database n Extensive queries n Aerial photos n Access to other databases www. sfprospector. com CS 128/ES 228 - Lecture 14 b 13

What if we make the user compute? Google Earth • Free application that runs under most operating systems • Interfaces maps and satellite imagery with databases CS 128/ES 228 - Lecture 14 b 14

Google Earth n Comes in many versions n n Basic versions are free Enhanced versions cost modest amounts Part of a much larger suite of web-compatible software Provides an applications programmer interface (API) so that you can customize an application (GIS) CS 128/ES 228 - Lecture 14 b 15

Concerns for GIS/Maps on the Internet n How much to restrict user interface? Who is the audience? n What are the copyright issues? n What are the privacy issues? n n What technology to use? Support all browsers or just some? n Programming language or just scripting? n CS 128/ES 228 - Lecture 14 b 16

More Concerns. . . n Hosting/serving issues Who hosts? n Data Security? n • Are on-line updates permitted or only queries? n n Capacity? Scalability? Develop on-line or “port” upon completion? CS 128/ES 228 - Lecture 14 b 17

CS 128/ES 228 - Lecture 14 b 18