World Wind FAQ

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==Issues Downloading Tiles== ==Issues Downloading Tiles==
 +
 +To make sure there is no server-side problem check [[World Wind server status|Server status page]].
===Download Monitor=== ===Download Monitor===

Revision as of 15:02, 19 May 2005

This is a list of frequently asked questions. If you have any questions please read this before asking in the Forums or Chat.

Contents

Before Installing

How can I download NASA World Wind?

The latest patch is 1.3.1

The latest full version is 1.3

This version is clearly marked if you go to Help->About in World Wind.

To get the latest version visit NASA_World_Wind_Download

What about the source code?

The source code is for developers. It is an additional download to the Full Install. If you just want to use World Wind and look around, all you need is the Full Install.

If you want the source code as well, download both. Once you run the full install, copy the Data directory from your World Wind full install directory into your source directory.

System Requirements

Windows 95,98,ME compatibility

Version 1.3 of World Wind shouldn't have a problem running unless it is due to an older computer / video card. I would appreciate some feedback on this. The latest version removed the texture converter code so the annoying black dos box shouldn't show up.

Software Requirements

The installer should detect and direct you to install these by default. If you are installing these because you believe there is an error, please install in the order listed below.

Microsoft .NET 1.1

Microsoft Directx 9.0c (December 2004 redistributable)

Minimum configuration

With the minimum configuration, performance and functionality may be less than expected.

  • 700 MHz or higher CPU
  • 128 MB RAM
  • 1 GB disk space (World Wind's cache size is 2 GB by default; you must reduce the size of your cache - Someone put a link here or instructions)

Recommended configuration

  • 1.4 GHz or higher CPU
  • 256 MB of RAM
  • DSL/cable connection or faster
  • 3 GB of disk space

Installation

CRC Error

Version 1.3
  • Some people recieve a CRC error when downloading the installer. This is caused by a corrupt download. Please redownload the program. (I would highly appreciate if someone could check MD5 sums as listed on the NASA World Wind Download page, and verify that this is a corrupt download. Also, if you repeatedly receive the same corrupt download from a particular server, please notify us immediately. User:Llynix)

Error writing file ______

  • The installer requires about 700 megs on your windows drive (usually c:) to install. This is regardless of where you install it to. Normally users who don't have room to decompress the files have this problem.
Version 1.2e and older versions

Please install the Latest Version.

Problems After a Successful Install

Every time I try to run the program it crashes with a "JIT debugger" error message.

Yikes, these are the worst. A few notes when trying to debug these. The process ID and thread ID are pointless and don't really help at all. Any other error codes you might receive may be helpful. Do not be concerned that there was no debugger found. As we get more organized and get more of an idea what errors are coming up I will try to post additional information here.

Some people have reported that installing the software requirements listed above has fixed their issues.

if someone understand this .it may help! http://thinstall.com/help/?debugging_netapplications.htm

Error x135

More information is needed. I would like a full error code (If I recall this is a hex code, and it has a C in front of it followed by a lot of zeros.)

0xc0000135

Error x02

More information is needed. Would appreciate the full error code.

cordbg.exe !a 0x5b4 code

More information is needed. Perhaps a .NET 1.1 issue?

Program Crashes with "unable to load font 'Tahoma Bold' (9em)?"

This is a known issue and should be fixed in 1.3.1

Please download the latest patch.

My video card isn't working

Check out the Video Card Compatibility list. Please, by all means, edit it depending on whether yours works.

Ensure that your video card drivers are up to date.

Try going to Start->Run and typing 'dxdiag'. This should load up the DirectX Diagnosis program. Under Display please make sure everything is working and enabled.

Why am I getting an error about "mscorwks.dll"?

This is an old error that shouldn't be affecting users anymore. I would like feedback if someone does experience it with 1.3 or higher.

Most likely, you've got .NET 1.0, but World Wind requires .NET 1.1. Just download it from here, and you should be up and running.

Issues Downloading Tiles

To make sure there is no server-side problem check Server status page.

Download Monitor

World Wind version 1.3 has a download monitor which can be very helpful diagnosing problems. Hold down Control (Ctrl) and hit H.

Why am I getting 'Problem connecting to server. Trying again in 2 minutes'

Several possible reasons:

  1. May be the server is down. You could say... try again in 2 minutes.
  2. You may be behind a blocking proxy/firewall. You'll need to configure a port remapper, or hunt down an admin to help. See below.
  3. You could be in a country that blocks access to worldwind sites & download servers. Try to find a proxy? We haven't yet had any confirmed reports of this.
  4. Remember to use the HTTP Download Monitor (CTRL+H) to see what exactly is going on.

Is there a way to set a proxy?

The current version of worldwind has limited proxy support. (I believe it defaults to the proxy settings in Internet Explorer.) Future versions should feature a more robust proxy support.

Proxy Issues

Gillesk is working hard on proxy support. I need to link and put more information here. you should use a portmapper like "AnalogX PortMapper" downloadable @ http://www.analogx.com/files/pmapperi.exe ps: concerning people who are behind a proxy

Why are the wrong image tiles showing up?

Possibly and probably due to the server bandwidth issues.

A workaround is to delete the numbered folders in the "cache" directory, but then of course you have to re-download all the images the next time you run the program. It's not obvious which particular cache files correspond to the "bad" areas.

You can also use a DDS viewer to browse and delete the offending files:

  • Nvidia's DDS viewer — By installing this you can switch to thumbnail view in the explorer and find and delete those nasty tiles.
  • Another good DDS format reader is Irfanview.

Also it is entirely possible that you are viewing more then one layer. Go to the layer manager and under images make sure only one box is checked. Otherwise things look very messed up.

If you do manage to find a "bad" tile using a server and upon reconnecting keep on downloading that same "bad" tile, please kindly record the filename and level (folder number) of the tile and let someone know. I should probably point to a wiki link but I don't know where it is right now. Does anyone ever actually read this FAQ?

Imagery related questions and tips

The questions we get every day

Aah! I zoom in and it's all blurry! Help!

Most likely, you either don't have the hi-res imagery turned on (USGS 1m and USGS Urban, see below) or you are looking somewhere that it isn't avaliable (i.e., anywhere outside the US). If you're outside the US, you're at the best it'll get. If you're in the US, make sure the hi-res imagery is turned on (either by selecting the buttons on the toolbar or ticking the checkboxes in the layer manager), and if it still doesn't work, it may be a downloading issue - look elswhere for troubleshooting.

USGS Imagery of Washington, D.C.
USGS Imagery of Washington, D.C.

Why am I not getting pictures like this --->

That is the USGS Urban Area Imagery. See below.
Note: USGS Urban Area Imagery data only exists for some cities in the US. Click here for a list.

Why can't I see my house/car/etc?

Landsat 7 data is available globally and you can pick out many prominent features in your location. The resolution is 15m per pixel (Community/OnEarth Landsat) and 30m per pixel (NLT Landsat), so you can see major highways, airports, or city centers. However you probably won't be able to see your house and certainly not your car.

USGS 1m / topography cover most of the US. You can see most buildings and roads. You can probably find your house.

USGS Urban is about .25m/pixel and only covers certain areas in the US. These are the color images you may have seen. You can generally see cars with this layer. Note that it is only avaliable for select cities. If you are not looking at the right place, you will be greeted by a sea of white nothing. This is normal - try to find a city listed at the link below. List of USGS Urban Cities

Pivot Irrigation
Pivot Irrigation

What are these crazy circles?

These are fields watered by a method called pivot irrigation. See this thread for more information.

Can I use this for international locations?

USGS data covers only the United States. You are more than welcome to view it all you want, but please don't complain that your area is not covered. It is unlikely that the United States Geological Survey will collect data for areas outside of the US.

Work is in progress for additional data sets. While there is imagery for many other locations, most of this imagery is licensed and is not freely available. If you know of any public domain or unrestricted datasets that we can incorporate please feel free to tell us about it.

These forum posts have information about other countries: Norway Iceland Canada Australia

We encourage all international users to contact their local politicians about releasing GIS data for all to use.

When was this imagery photographed?

Depends on the layer. The NLT Landsat7 and OnEarth Landsat7 are from 1999 to 2003, with 2000 being the most active year. The USGS 1m Digital Ortho varies more. It was taken from 1990 to 2000. Search for a US location though TerraServer® and look for the USGS entry. The USGS Topo maps vary from within the past few years to more than a decade ago. Streets and building locations in particular may be quite out of date even if the terrain has changed little. USGS Urban Area Ortho dates from 2001 to 2004 and some areas are still being photographed, you can see the datase ages at the USGS site.

Can I see the world in real-time?

This just isn't practical and won't be possible anytime soon. To do this requires a network of satellites dedicated to covering the earth. Just to provide as much detail as the base layers WorldWind loads first, the camera resolution on each one has to total about 100 megapixels. Perhaps the military has such a network, but it is certainly off-limits to anyone else. The images have to be received on the ground and processed. Then they all have to be combined where they overlap and corrected for the distortion caused by the earth's curvature. Finally after compressing the imagery from gigabytes down to several hundred megabytes, a server has to send it out to everyone. This requires an enormous amount of bandwidth for the server. Even if that weren't a problem, the internet connection for the majority of high-speed users is still too slow for more than about one update every hour.

Landsat

With the new landsat, what's with the colors? Why isn't my area covered?

NLT Landsat 7 button
NLT Landsat 7 button

Nasa Learning Technologies has stated there will be additional tweaking and alterations to the coloring. There will be a white paper describing the techniques used, and it will improve over time.

Consider this NLT global mosaic version 0.1, you haven't seen anything yet.

NLT servers are working around the clock to process the entire world. Currently only certain areas are in place. Please be patient your area will be there very soon.

The NLT dataset is not yet as high quality as the original ("OnEarth" or "Community") Landsat7 datasets are. The NLT dataset has not been pansharpened yet. NASA feels it is of higher priority to complete a "rough copy" then it is to sharpen it as that takes 4x as long. As soon as coverage is complete look for a pansharpened layer to start trikling around the globe.

Problems connecting to OnEarth / Limited resolution compared to 1.2e

Recently OnEarth, who was serving the original Landsat layer, blocked access to World Wind users.

This is why older versions of World Wind do not work without the proxy/mirror patch, and why newer versions of World Wind (1.3) use the proxy patch by default.

Lucian at the onearth server has also asked us not to proxy the data. At this point the only access to the old landsat is the incomplete mirror served from worldwindcentral.com.

Work is underway to remedy this situation.

Latest news (2005-04-24): See http://www.worldwindcentral.com/wiki/World_Wind_Central_Add-on_Pack for a patch that addresses this issue, and http://forum.worldwind.arc.nasa.gov/index.php?showtopic=2743 for the related announcement on the NASA site.

USGS

How do I load the .25 meter resolution maps, as shown in the screenshot of D.C. on this web site?

USGS Urban button
USGS Urban button

You can access these images by either selecting Layer Manager->Images->High Resolution Terrain Mapped->USGS Urban Area, or clicking the USGS Urban button.

All I see is white tiles when viewing the USGS Urban data!

USGS urban data is not available for all areas. If you aren't looking in the right place (in one of the cities listed at the Terraserver website, you'll see whitish green, and nothing else. The Urban Layer Highlighter is extremely helpful locating areas.

How to make use of the USGS layers

USGS is the acronym for U.S. Geological Survey. In other words, the data that is available in the USGS layers is only for the USA. While it is possible that similar data is available for other parts of the world, most of it is not freely available, and therefore is not incorporated into World Wind. See Using_the_USGS_Layers for step-by-step illustrated instructions.

SRTM

Why does <insert mountain or other relief feature> not look like it should?

Illustration
Illustration


This is due to the fact that the elevation data, SRTM, is taken much like sonar measurements - the elevation is "sounded" from a satellite. Unfortunately, these "soundings" are only taken about every 90 meters, so the data isn't incredibly accurate. As a result, mountains and such (for example, Matterhorn) may look strange. Imagine the satellite collects elevation points in a grid. So it flies over the Alps where two peaks are 50 meters apart. It takes one reading, say, 40 meters away from one peak's top, but manages to hit the highest point of a different peak right on the top. It never hits the first peak's tippy top.


Referring to the illustration, say the vertical blue lines are measurements taken. The red line will be what Worldwind shows, grey being the actual landscape. The left peak shows as being higher in WW, but the right one is actually the highest.

In addition, different materials and ground coverings may give false readings, which contribute to other inaccuracies.

Cache and data related questions

Can you make the amount of cache adjustable?

Please see your WorldWind.exe.config file. Open it with notepad (or any text editor) and you can easily adjust the cache size.

Can I copy my cache data to another computer?

Yes you can. Click here for discussion.

Can I use my 1.2e cache in 1.3?

Yes you can. See: Converting 1.2e Cache for use in 1.3

How large is the data set? Is it available for download?

Collectively the data sets are around 4.6 Terabytes. As such they are not available as a full package for localized download. There are, however, several data sets available for download as cache packs.

How about bittorrent for the data sets?

Because of the size of the data used, and the limited amount of data users download of the total available data, it is unlikely that p2p would make much of a dent in the problem of serving that data.

But see above.

Known Issues

Is there a way to narrow down a search for a place?

We realized this problem almost immediately (there are approximately 2 million places with 3 million more about to be imported) and we're going to associate a "Place" with a country or geographic identity. Perhaps you will type in "Paris France" and you will only get matches that have those two keywords. Also, if anyone hasn't noticed, the searching tool is case sensitive, and that will of course be changed as well.

In addition, we want to display more meta-data information about a particular place, such as the type of place(mountain, populated place, beach...), and perhaps attributes such as population or elevation. We of course are open to suggestions that anyone else might have in terms of what would be useful.

Several people are working on placenames right now. Stay tuned.

There are place names all over the place!

Yes, the amount of placenames is a bit of a nuisance, and we're working on ways to remedy this problem. We still want those placenames in there, we just don't want them to take up so much real estate on the screen.

— Side note,if you go to the layer manager (view / layer manager) under placenames you can click off certain ones. It may be helpful to remove the one labeled "US Anthropogenic Features" which contains info about churches, schools and other landmarks in the US.

The entire time the application is running, it uses 50-100% of the CPU, why?

World Wind was not coded for performance, sadly. At least, you can rest assured that this problem is very common and most users experience it - there is nothing wrong with your computers. This will get optimized in future releases, but we're still heavily in the Research & Development stage.

Also there are a few bugs attributed to high CPU usage. Check out:

http://learn.arc.nasa.gov/worldwind/forums...p?showtopic=372

Tips

How can I extract data from Worldwind for use in other modeling and mapping applications?

All the data is cached in the installation folder under the "Cache" directory. It's organized by the dataset, however, images are in DDS compressed format. Please see above for DDS viewers.

You may have more luck reading up about the WMS protocol, and then interfacing with the same servers that WW connects to.

Are images on World Wind copyrighted?

The Landsat Global Mosiac, Blue Marble, and the USGS raster maps and images are all Public Domain.

Can I use images on World Wind for commercial purposes?

The various servers you receive data from do request that you give them credit, however this is not required. You may do what you wish with these images.

What is the most proportionate "vertical exaggeration"?

Although it seems that 2 or 3 should be the "correct" vertical exaggeration, "1" is the correct and real vertical exaggeration. More correctly, "1" means that the vertical height is multiplied by 1.0, whereas vertical exaggeration of 3 means that vertical height is multiplied by 3.0.

Secret Keys

  • Wireframe: Ctrl+W
  • Diagnostic Info: Ctrl+D
  • HTTP Monitor: Ctrl+H

Keyboard_actions

Future Versions

When will the next version be out?

Check the Road Map for information on future versions.

Do you think you could add boundaries of other sub-national entities, such as Swiss cantons, Australian states, and Canadian provinces and territories?

Chris : It's coming.

Llynix - the only reason these files aren't in there is they haven't been generated yet. If you have some free time, and a basic knowledge of computer programing why not volunteer to convert them?

Please see Additional Boundaries

Update - A ton of people took the call and made up boundaries, but now we need to sort them, get them in one place, and check the validity and political correctness of these files. Then integrate them into the WW boundary pack. Boundaries for the Canadian provinces and territories are now included.

Meanwhile boundaries could use some optimizing.

How about other planets?

Mars is in beta testing right now. I am personally hoping for Venus next, but with the data available it may likely be the moon..

I would love to see a feature that showed day/night in realtime say taken from the USNO atomic clock. Perhaps a setting where you could follow the terminator and such.

It's on our list, slightly more elevated now that you asked for it.

Stars?

Chris : We actually have plans to import a "Military-Grade" star map. It's probably overkill, but we like it that way.

I think Chris is referring to: http://skyserver.sdss.org/dr1/en/

Maybe we could use same star catalog as Celestia: http://www.shatters.net/celestia/download.html

Will there be an option to export animations/movies in the future?

Developers

What license is World Wind released under?

Nasa Open Source license v1.3.

Will World Wind remain always free?

Chris:

The program itself is open-source and will always be free. Access to NASA provided data will also remain free. However, there might be private companies that want to provide their data through World Wind (perhaps magazines or encyclopedias) and perhaps might charge a fee for access to their data. As long as there are people who want NASA provided data, and are using World Wind for that purpose, it gives the departments in charge of providing data a reason to ask for more funding to improve bandwidth to the data.

Why did you decide on C# and DirectX?

See this forum posting: http://learn.arc.nasa.gov/worldwind/forums...w=findpost&p=17

Mac and linux ports?

Since this is open-source, we encourage any OSX programmers to start a port and we will try our best to provide whatever resources we can towards the effort. Right now our development staff consists of one programmer and one graphics designer, but we are an ambitious duo so we will do our very best to please everyone.

For more information:

http://learn.arc.nasa.gov/worldwind/forums...p?showtopic=133

In what areas do you need the most help? How can I contribute?

Check the How to Get Involved page to see how you can help with the World Wind project.

When is the planned migration to sourceforge?

Done! CVS is up and people are adding bugs and feature requests.

Links

What data does World Wind use and where can I access it?

World Wind Data Sources

Where can I find more links?

Please see this forum : http://learn.arc.nasa.gov/worldwind/forums...owtopic=411&hl=

And this forum : http://learn.arc.nasa.gov/worldwind/forums...owtopic=679&hl=

Simplified Chinese Version of this FAQ

SC Unofficial FAQ

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