World Wind Users Document

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World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and Shuttle Radar Topography Mission (SRTM) elevation data to experience Earth terrain (or any planet with the data) in visually rich 3D, just as if they were really there. Virtually visit anyplace in the world. Look across the Andes, into the Grand Canyon, over the Alps or along the African Sahara. World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and Shuttle Radar Topography Mission (SRTM) elevation data to experience Earth terrain (or any planet with the data) in visually rich 3D, just as if they were really there. Virtually visit anyplace in the world. Look across the Andes, into the Grand Canyon, over the Alps or along the African Sahara.
-World Wind downloads and displays data from numerous data sources, such as LandSat7, MODIS and USGS (1-Meter, Topo and Urban). Using these various sources of images, you can zoom in close enough to see people walking in the streets of many of Americas cities.+World Wind downloads and displays data from numerous data sources, such as LandSat7, MODIS and USGS (1-Meter, Topo and Urban). Using these various sources of images, you can zoom in close enough to see people walking in the streets of many of America's cities.
====Features==== ====Features====

Revision as of 04:08, 31 March 2005

(See discussion tab for layout of "finished" TOC)

World Wind Documentation / Walkthru

Written and Maintined By: Chad Zimmerman

Edited By: (the world :)

Version: 0.2

Date: 03/01/05

Version Location:

Contents

Introduction

Blue Marble: View of the eastern hemisphere
Blue Marble: View of the eastern hemisphere
SRTM + LandSat 7: Mt. St. Helens, Washington
SRTM + LandSat 7: Mt. St. Helens, Washington
USGS Urban Area Ortho Imagery (MS Research Terra Server USA): Washington D.C.
USGS Urban Area Ortho Imagery (MS Research Terra Server USA): Washington D.C.
MODIS: 10-4-2003, Hurricane Kate, Atlantic Ocean
MODIS: 10-4-2003, Hurricane Kate, Atlantic Ocean
SVS: GLOBE, 08-11-2004, Maximum temperature
SVS: GLOBE, 08-11-2004, Maximum temperature

About

World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and Shuttle Radar Topography Mission (SRTM) elevation data to experience Earth terrain (or any planet with the data) in visually rich 3D, just as if they were really there. Virtually visit anyplace in the world. Look across the Andes, into the Grand Canyon, over the Alps or along the African Sahara.

World Wind downloads and displays data from numerous data sources, such as LandSat7, MODIS and USGS (1-Meter, Topo and Urban). Using these various sources of images, you can zoom in close enough to see people walking in the streets of many of America's cities.

Features

World Wind offers the following features:

  • Rapid Fire Modis — For getting near real time images from orbiting satellites with resolution down to 250Meter. You can filter the MODIS data by date and by event. Data is then downloaded and displays an icon in World Wind showing what event it is and where it happened. You can zoom in to view the event.
  • LandSat7 Images — LandSat 7 is a collection of images from 1999-2003 at an impressive 15 m per pixel resolution. It includes other color bands such as the infrared spectrum. Users will be able browse these different sets as they become available. Any changes and updates are automatically inherited by World Wind. LandSat 7's resolution makes it possible to see your own city, neighborhood, or landmarks in your vicinity. Seeing the whole globe like this puts the world in context with scientifically accurate data. You can view LandSat imagery in visible colors or in False Color bands.
  • WMS Browser — Web Mapping Server. (Not sure what this does.. need info)
  • SVS (Scientific Visualization Studio) — Goddard Space Flight Center (GSFC) has produced a set of visually intense animations that demonstrate a variety of subjects such as hurricane dynamics and seasonal changes across the globe. World Wind can take these animations and play them directly on the world. Anyone can immediately grasp where the event is taking place as World Wind rotates automatically into view.
  • Blue Marble — World Wind has a full copy of the Blue Marble, a spectacular true-color image of the entire Earth. Put together from data of a variety of satellites such as MODIS and Terra, the Blue Marble can be seen in all it's glory at 1 km per pixel resolution.
  • SRTM — Combining LandSat 7 imagery with Shuttle Radar Topography Mission (SRTM) Data, World Wind can display a dramatic view of the Earth at eye level. Users will literally be able to fly across the world in any direction.
  • USGS — United States Geological Survey data. USGS provides Topography maps, 1-Meter detail images of most of the United States and Urban Area images of most of the major cities down to detail of .25 Meter.

Requirements

  • Windows 2000, XP Home, or XP Professional, Windows 98
  • Intel Pentium 3 1 ghz or AMD Athlon or higher
  • 256 MB of RAM
  • 3D Graphics Card (64 MB+ recommended)
  • DSL / Cable connection or faster (It does “work�? on a modem connection.)
  • 2 GB or more of disk space

Contact

There are several ways to contact the developers of World Wind.

Website:

http://worldwind.arc.nasa.gov/

WiKi:

http://wiki.worldwindcentral.com/

Forum:

http://worldwind.arc.nasa.gov/forums/index.php

FAQ:

http://worldwind.arc.nasa.gov/forums/index.php?showtopic=148

IRC:

http://worldwind.arc.nasa.gov/forums/index.php?showtopic=774

Email:

Installation

Download Location

As of the latest date on this document, the current version of World Wind is 1.3. You can download the latest version of World Wind from this locations:

Installing World Wind

<< Needs to be filled in >>

The Configuration Files

In the NASA folder there is a folder called "Config" where you will find all the settings for World Wind. These files have a XML extension but are plain text files that can be edited by any text editor such as notepad. The configuration files are as follows: wms_server_list.xml, WorldWind.exe.config, WorldLayers.xml. Each configuration file controls a different aspect of World Wind.

wms_server_list.xml

Defines the servers that you download the Animated Earth Visualization data and the GLOBE Visualization data.

WorldWind.exe.config

Located in the main World Wind directory, this file lets you set cache size and directory using:

<add key="CacheDirectory" value="D:\NASA\CACHE"></add>
<add key="CacheSizeMegabytes" value="2000"></add>
WorldLayers.xml

The meat of the configurations. Controls the settings of World Wind that are not in the other two configuration files.

Startup / Using

Starting World Wind and General Controls

Key chart
Key chart

To start World Wind, click on the desktop icon that looks like this: Image:Wwshortcut.gif

This will launch the application and you will see a start screen. Note: some users have reported it locking up at this point. And some have got past this lockup by pressing Alt+F4. It stops the boot screen but not World Wind itself. Once World Wind is loaded, you will see the default Blue Marble view of the Earth. Now for the commands to use World Wind. You can use your mouse or keyboard to control World Wind's views.

Mouse Commands
Left Mouse Button = Hold this button down and move the mouse to rotate the earth to the right or left, top or bottom.
Right Mouse Button = Hold and drag your mouse to tilt the earth to see the 3D views of an area that has SRTM data. You will not really notice this function till you zoom in closer to a point on the earth.
Both Mouse Buttons = Zoom in and out of the Earth.
Scroll Wheel = Use this to zoom in and out of the Earth.
Keyboard Commands

To use the keyboard commands, look at the file called “keychart‿ in your World Wind root directory. Toolbars and Menus: World Wind has one row of menu choices and a toolbar of quick access features. The file menu choices are “File‿, “View‿, “Tools‿ and “Help‿.

File
Save Screen Shot - Saves a screen shot of your current view of the world in World Wind
Exit – Exits World Wind
Edit
Copy Coordinates - Copies a string similar to this, worldwind://goto/world=Earth&lat=64.21778&lon=24.72139&view=0.18390, to the clipboard. It can be used as a URL in an HTML document. Clicking the link will open World Wind and load the Lat/Lon and Altitude for that location.
Paste Coordinates
View (Has some of the same choices as the Toolbar)
Show Toolbar – Turns the toolbar on and of
Show Lat/Lon Lines – Turns the Lat/Long grid on or off
Lat/Lon Line Color – Sets the color of the Lat/Lon lines
Show Planet Axis – Turn the axis line (show the poles) of the earth on or off
Show Cross Hairs – Targeting cross hairs that show the center of your view
Show Position – Turn on the display of the Lat/Lon lines, Heading and Altitude
Motion Momentum – When enabled, when you move the Earth with the mouse it will keep moving in that direction and speed
Point Go-To – When enables, where you click on the globe, the view will rotate to that point so that it is the center of your view.
Vertical Exaggeration -
Always On Top -
Fullscreen -
Tools (Like View as the Toolbar choices)
Layer Manager – Opens the Layers so that you can enable and disable layers in World Wind
WMS Browser – Loads WMS
SVS – Loads the Animated Earth
Rapid Fire MODIS – Loads the MODIS interface
Place Finder – Loads the World Wind search function
Help
Keychart - Loads the key chart image
Website – Loads the World Wind website
About – About World Wind
Useful Sites – A listing of World Wind related sites
Toolbar

The toolbar is a quick link resource to the most commonly used World Wind layers. It can be turned on or off via the Tools > Show Toolbar menu choice. The toolbar looks like the one pictured below. It can differ if extra Add-Ons have been added to World Wind.

Navigating in World Wind

Accessing Data Views

There are several different types of data views to World Wind, you read about them in Introduction section of this documentation. The most commonly used icons are located on the toolbar of World Wind.

Blue Marble

Blue Marble is what loads by default in World Wind. It is 4km to 1km resolution images of Earth. Once you are zoomed in past the 1km resolution of the earth, the LandSat7 Layers then start to load. Blue Marble Imagery is show down to an altitude of 780,000 meters.

Creating World Wind Add-Ons

Introduction

Add-On Types

Currently, there are two types of Add-Ons. As World Wind progresses, more will most likely come to be used. For now this document will cover the two main types in use now.

  1. Point Listing - This kind of Add-On is used if you want to mark certain locations on the globe. You can also include an icon with this feature and it can be made clickable so you can send users to a web site with more information.
  2. Path Line - This kind of Add-On can incorperate the one listed above, and also includes a Path feature so you can show a trail on the globe with icons are certain points.

Building an Add-On

As stated above there are two types of Add-Ons. Here are the instructions on building them.

Point Listing

A Point Listing Add-On is based around a file and a file set. The file is the XML file tht supplies all the location ond configuration data for the Add-On. The file set contains the images for the Add-On including the icon that is displayed in the toolbar.

  • XML File

Below is a sample from the Add-On I created which displays Federal Electorates in Australia.

<?xml version="1.0" encoding="UTF-8"?>
<LayerSet Name="Australian Commonwealth Electorates" ShowOnlyOneLayer="false" ShowAtStartup="false"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="C:\WorldWind\bin\Debug\Configuration\EarthLayers\LayerSet.xsd">
<Icon ShowAtStartup="true">
<Name>Canberra</Name>
<Latitude><Value>-35.569567</Value></Latitude>
<Longitude><Value>148.998003</Value></Longitude>
<DistanceAboveSurface>100</DistanceAboveSurface>
<TextureFilePath>Add-ons\Earth\AustralianFederalElectorates\Icons\alp.png</TextureFilePath>
<TextureWidthPixels>128</TextureWidthPixels>
<TextureHeightPixels>128</TextureHeightPixels>
<IconWidthPixels>42</IconWidthPixels>
<IconHeightPixels>42</IconHeightPixels>
<ClickableUrl>http://www.aec.gov.au/_content/who/profiles/profiles/c/canberra.htm</ClickableUrl>
<Description>Commonwealth Electorate</Description>
</Icon>
<ExtendedInfomation>
<ToolBarImage>Add-ons\Earth\AustralianFederalElectorates\Icons\CoatOfArms.png</ToolBarImage>
</ExtendedInfomation>
</LayerSet>

Most of the tags above are fairly self explanatory (if you are having difficulty with XML see the W3C XML site). All the fields must be present otherwise World Wind will not be able to load the Add-On (and will throw an error during start-up).

For multiple icons in your Add-On simply repeat the

<Icon>
...
...
</Icon>

section.

The XML file should be placed in the $WorldwindHome/Config/Earth/ folder (change Earth for the appropriate planet if necessary).

  • File Set

The file set should be at the location specified in the <ToolBarImage> and <TextureFilePath> tags.

Path Line

Appendix

About LandSat7 data

It is incredible that it is as good as that. Landsat7 only gets one chance every 16 days, at about 10AM (???), to cover any given area. If there are clouds, fog, smog, snow on the ground (too white), too much grass on the ground (too green), too low or too high sun angle (low contrast), satellite maintenance, solar storm ..., that chance is lost. A few bad takes in a row, and a whole year is lost. A scene is 160x180km, and a perfect scene has to have perfect conditions for the whole area.

Landsat7 was launched in 1999 and now it has some data quality problems. No replacement/equivalent satellite is planned, at least not an inexpensive, US funded one!

This dataset (GeoCover 2000) and mosaic (WMS Global Mosaic) will be the best available global images for quite a while, and the fact that they are free and available on the net makes them even more significant.

LandSat7 resolution is 15 meters per pixel.

NASA OPEN SOURCE AGREEMENT VERSION 1.3

See NOSA for the full NASA Open Source Agreement

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