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28

I think the stock/obvious answer would be to use a spatial database (PostGIS, Oracle, SDE, MSSQL Spatial, etc) in conjunction with a metadata server such as esri's GeoPortal or the open source GeoNetwork application, and overall I think this is generally the best solution. However, you'll likely always have a need for project-based snapshots / branches / ...


26

I played with this topic a lot some time ago. You can find some examples here: Dobrou extensions plugin examples Dobrou extensions plugin homepage Using Sporttracks and this plugin, gps tracks can be converted to KML and displayed in Google Earth. It supports some ideas mentioned here - track coloring based on color gradient, direction arrows and much more. ...


22

I've always done it as width. For example you create a buffer around each point that represents speed and then dissolve the buffers into one. Narrow areas indicate bottlenecks. For an example see: http://www.fmepedia.com/index.php/Bufferer Of course, you can even color code the buffers before merging them. For an example see: ...


21

Good question. Geography, and later GISc have been struggling to incorporate 4th dimension since Torsten H├Ągerstrand brought time into geographic research. Couple of things from the top of my head: One of the solutions is to use 'space time aquarium' where in 3D space you can use X and Y to represent location in space and Y to represent time. Two names ...


20

There's always the "brute force" method: Take a layer with a known coordinate system that is supposed to overlay with your unknown layer. Now make some educated guesses on what projection the unknown layer could be. (UTM, Plate Carree, etc). Project your known coordinate system layer into each projection until you find one that matches the unknown ...


19

A simple and efficient way is to color the segments depending on their speed. For example, "fast" segments can be displayed in green and "slow" segments in red (other colors can be chosen of course). Example on an orienteering-running GPS trace using the software Chmuk: Another example with the software quickroute: The parts of the route where the ...


15

I'm promoting comments by Mapperz and Brandon Copeland by adding an answer that uses their technique. If you have ArcGIS Desktop, add some reference data that covers the same area to ArcMap. This reference data must have a valid coordinate system (projection) definition. Add the data in an unknown coordinate system. Research what possible coordinate ...


14

Metadata is by far the most important issue here. If metadata answers whom, when, why, where it's an acceptable metadata record. Having work experience in large companies with just a few GIS users (around 30) we had major issues to control data, specially versions and permissions. One side of this can be solved with extensive documenting of data (metadata) ...


14

This is a wicked problem. We've tried various systems, which have all worked to varying degree for a time, and eventually grown unwieldly and started to fall apart as more and edge cases which don't quite fit are encountered. That said, each of the systems we've used is way better than nothing, proving the maxim that any system is better than no system. ...


14

There are two great links from Esri that go into detail on this: Identify an unknown projected coordinate system using ArcMap Identify the spatial reference, projection, or coordinate system of data


13

I think the literal answer to your question is "not really" (aside from things like blue=water or blue/red=Dem/Rep). It depends on how/what other data is displayed on a map and the map's purpose whether, for example, county boundaries are a light color or dark color. There are plenty of places where color choice is discussed. Some examples of books (I'm ...


12

I think you may be interested in work described as time geography, and you may want to use search terms such as space-time-path or space-time-cube. In the space-time-cube technique I would imagine you could still use color to represent velocity of the movements, although it is inherently represented in the space/time distance between nodes on your path. ...


11

Believe it or not people, you might be surprised what a simple google search can sometimes reveal!! At my last job, I had a layer of Geology data (polygon) named "FSU_Geol.shp". My boss gave it to me and asked me to find out a number of things. First off, he was handed this shapefile by the client, and there was no .prj file, so he wanted me to figure ...


10

You can record the position of the vehicle with a regular time interval and gradually fade out old time points. Adding a line at each point whose length is representative of the speed can help too. Below is an example from Microsoft Research. It's quite easy to see the relative speed of different countries in this graph. ...


10

Since you have multiple objects being tracked I would go with using color to differentiate objects and instead of colour to show speed, I'd use thin lines perpendicular to the direction of movement illustrating 10 second intervals (say). Closer lines = slower. Not the best sketch below, but you get the idea:


9

Not a tool (I don't know of one in existence that would let you do that), but check out @mkennedy's reply to a similar question. She explains how she arrived at the correct spatial reference. SpatialReference.org and patience will be your friends. Additionally, ESRI provides a guide on how to guess a coordinate system (though I prefer mkennedy's method if ...


8

I think I would go for something in the direction of Trevesys suggestion but only with dots instead. Longer between the dots means faster and closer between them means slower. It is easy to think of the speed like, high speed should get a more powerful visualization, but I am tempted to think the reverse because the symbol is bounded to a special place on ...


8

You might be interested in my slides from a SXSW panel on geotemporal visualization. While they don't cover every single approach, they do a pretty good job of offering examples for the most common approaches (note that many of these examples require a browser with SVG or Canvas support, so not IE<9): Showing time as a line on a map Showing time as map ...


8

How about arrow symbols? Length of arrow = speed of the object at that location. You also get direction for free. And the whole thing is very intuitive -- no need to glance over at the legend to remind yourself of the interpretation. It's used all the time for wind-speed maps, but there's nothing saying you can't symbolize objects this way too: ...


8

Seriously outdated at this point, but Werner Flacke and Birgit Klaus posted Find Projection on ArcScripts in 2007. I don't think the source code is there, unfortunately. It's VBA-based so only usable in ArcGIS Desktop v9.2 and possibly 9.3. It does include two shapefiles with the areas of interest from the EPSG Geodetic Parameter Dataset which could be used ...


8

The best answer I've found to this question is non-technical: find out where your data came from. Agencies and organizations tend to be consistent with their use of projections. Know it came from your state DOT? Look at the rest of their data and see what it tells you. Don't know where it came from? An educated guess is just as likely to send you down the ...


7

We have used a file system organized hierarchically by: - geographic extent (country or continent) - data provider, licensor - domain/dataset - date/version After that we have a policy to separate the source data (in the same format that was on whatever CD/DVD that we got from the provider) from any derived datasets that we produced within our company. The ...


7

If you're looking for a video output, commercial tools like EONfusion can make nice 3D environments with temporal information. Similarly, I agree Google Earth (and its plugin) are a simple tool for visualizing interactive temporal data. Visual Complexity keeps a database of network visualizations, many of these are spatio-temporal visualizations, such as the ...


7

You might want to have a look at some of Gennady & Natalia Andrienko's papers. They have published extensively on the issue of geovisualization of movement data and some of their output might be helpful here. Cooper Smith has also done some interesting work using processing.


7

I don't have an answer for everything, but will give this a shot...I work for a utility setting up a GIS system for land acquisition, maintenance and engineering. We have a whole system of checks and balances where the behind-the-scenes IT server information is not something that I maintain, but can give you a glimpse of what we've seen with our production ...


6

That is actually something you will find little documentation on publicly. There are classes/workshops that ESRI charges for or that you can attend at the ESRIUC but less in the public space. A couple of the points you mention come out of good DBA practices; but some really dont and really depend on your sytems and needs. For integrity, for sure a stable ...


5

This is relative; best colours for associative data. I say this because, when I was doing geography in high school, it was quite the taboo to draw anything other than water on the map as blue. Often losing marks when we did, even getting close to purple was avoided. When I went to college, major highways were colored blue, in fact, a trademark blue; Nova ...


5

According to Corine Land Cover Legend, "industrial" is purple. This convention relies solely on solid colors, no hatchings or similar.


5

I recently came across some of the work of Sidonie Christophe that has particular bearing to this subject. While in the particular paper I'm referencing (Christophe, 2011) she proposes a more general set of cartographic rules governing the choice of color for objects, the rules she proposes are so intuitive that I suspect they are in general implemented in ...


4

I really like using Google Earth for temporal data. Really nice platform for communicating, very smooth animation and relatively easy to 'program' Google Earth & Time Should be a list of animated chloropleths and volumetric there... have fun!



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