Introduction to geographic information systems by mike zielinski
Download
1 / 18

Introduction to Geographic Information Systems - PowerPoint PPT Presentation


  • 322 Views
  • Updated On :

Introduction to Geographic Information Systems by Mike Zielinski. Definition of GIS. Stores geographic locations and attributes about the location. Able to add information Edit information Examples terrain information, disease information, tree information. Examples of GIS. Google Earth

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Introduction to Geographic Information Systems' - PamelaLan


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Definition of gis l.jpg
Definition of GIS

  • Stores geographic locations and attributes about the location.

  • Able to add information

  • Edit information

  • Examples terrain information, disease information, tree information


Examples of gis l.jpg
Examples of GIS

  • Google Earth

  • Google Maps

  • CGIS – First Computerized GIS

  • ArcGIS-Current commercial GIS

  • Wikimapia


History of gis l.jpg
History of GIS

  • First were cave paintings showing where animals where located

  • First known analytic use was cholera outbreak in London in 1854 when Dr. John Snow used a map to figure out how to stop the outbreak


Demos l.jpg
Demos

  • Google Maps

  • Wikimapia


Google code l.jpg
Google code

  • Need key and a domain to embed in web site

  • Uses Javascript


Sample code l.jpg
Sample Code

  • <script src="http://maps.google.com/maps?file=api&amp;v=2.x&amp;key=key" type="text/javascript"></script>

  • <script type="text/javascript">

  • var map = null;

  • vargeocoder = null;

  • function initialize() {

  • if (GBrowserIsCompatible()) {

  • map = new GMap2(document.getElementById("map_canvas"));

  • map.setCenter(new GLatLng(37.4419, -122.1419), 13);

  • }

  • }

  • </script>


More code l.jpg
More Code

  • <body onload="initialize()" onunload="GUnload()">

  • <form id="form1" runat="server">

  • <div>

  • <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

  • <asp:Button ID="Button1"

  • runat="server" Text="Button"

  • onclientclick="showAddress();return false"

  • UseSubmitBehavior="True" />

  • </div>

  • <br />

  • <div id="map_canvas" style="width:300px; height:500px"></div>

  • </form>

  • </body>


Geolocating l.jpg
Geolocating

  • function showAddress() {

  • geocoder = new GClientGeocoder();

  • var address=document.forms[0].TextBox1.value;

  • if (geocoder) {

  • geocoder.getLatLng(

  • address,

  • function(point) {

  • if (!point) {

  • alert(address + " not found");

  • } else {

  • map.setCenter(point, 13);

  • var marker = new GMarker(point);

  • map.addOverlay(marker);

  • marker.openInfoWindowHtml(address);

  • }

  • }


Wikimapia l.jpg
Wikimapia

wikimapiaRequestStr = "http://api.wikimapia.org/?function=box&bbox=" + LonMin.Text + "," + LatMin.Text + "," + LonMax.Text + "," + LatMax.Text + "&key=key”

The key can be gotten at wikimapia.org/api

Returns XML with places in the box

Can return other formats like JSON, KML and also gzip it.


Xml format l.jpg
XML format

<code class="xml"> <?xml version="1.0" encoding="utf-8"?> <?access-control allow="*"?> <folder language="en" version="1.0"> <!-- places folder, language and version --> <place id="22139">

<name>Golden Gate National Recreation Area: Land's End</name>

<url>http://wikimapia.org/22139/</url> <!-- original url -->

<location> <lon>-122.4997044</lon> <lat>37.7887088</lat> <north>37.788878</north> <south>37.78681</south> <east>-122.494082</east> <west>-122.508352</west> </location>

<polygon> <point x="-122.5077081" y="37.7867756"/> <!-- points of polygon x - longitude, y - latitude --> <point x="-122.494082" y="37.78681"/> <point x="-122.4945974" y="37.7880983"/> <point x="-122.496593" y="37.7874539"/> <point x="-122.4973226" y="37.7875896"/> <point x="-122.4997044" y="37.7887088"/> <point x="-122.5002408" y="37.7885053"/> <point x="-122.5024295" y="37.788234"/> <point x="-122.5035238" y="37.7880305"/> <point x="-122.5060344" y="37.7882001"/> <point x="-122.5071502" y="37.7875048"/> <point x="-122.5071502" y="37.7875048"/> <point x="-122.5077081" y="37.7867756"/> </polygon> </place>


Xml parser in c l.jpg
XML Parser in C#

  • XmlReader wikiReader = XmlReader.Create(wikimapiaStream);

  • while(wikiReader.Read()) {

  • if (wikiReader.IsStartElement()){

  • if (wikiReader.IsEmptyElement) {

  • name = wikiReader.Name;

  • }

  • else{

  • name = wikiReader.Name;

  • wikiReader.Read();

  • if (wikiReader.IsStartElement() {

  • name = wikiReader.Name;

  • }

  • content = wikiReader.ReadString();

  • if (name == "name"){

  • ListBox1.Items.Add(new ListItem(content));

  • }


Other capabilities of wikimapia l.jpg
Other Capabilities of Wikimapia

  • Can Search

  • Can request URL for a place; need place id gotten from Box


Can be used with google maps and google world l.jpg
Can be used with Google Maps and Google World

  • THE KML format is used by Google Earth

  • The KMZ format which is KML zipped can be used by Google Maps to add information about the area like Google Earth.


Spatial databases l.jpg
Spatial Databases

  • Can add points, lines, and polygons to the database in SQLServer and MySql

  • I will talk about MySql but these are standards that have been implemented so should work for other databases.


Spatial types l.jpg
Spatial Types

Point- POINT(12.5 13.1)

LineString- LINESTRING( 0 0, 0.5 0.4, 20.1 20.5)

Polygon- POLYGON( ………………………..)

MULTIPOINT holds many points

MULTILINESTRING holds many line strings

GEOMETRY can hold any type


Use of types l.jpg
Use of types

  • Create Table PointsAndLines (pt POINT,Line LINESTRING);

  • Insert Into PointsAndLines

    Values (GeomFromText(‘(POINT(1 1)’)),…);

  • Select AsText(pt) From PointsAndLines.


References l.jpg
References

  • Wikipedia-GIS

  • Wikimapia.org/api

  • code.google.com/apis/maps

  • dev.mysql.com


ad