Is there a way I can build terrain data in a simple way from sources like Google Maps. I am not interested in heights but a simple 2D representation will be good enough.
For instance, I am trying to represent a terrain using the roads and buildings inside a map to model a traffic simulation. Representing objects like buildings is necessary so that when my cars are moving on a road, they should know when to take a turn etc. Are there any standards for representing these?
There are dozens of map standards. also map data tends to be very expensive, although there are some low cost and open source map sources. Eg. OpenStreetMap, and for the US, Tiger/Line.
I would also read up on, at least, some introductory GIS - I think you'll find the field is much bigger and more complex that you are initially thinking.
Related
I'm interested in implementing some data visualizations as map layers. But I'm interested in generating data layers only above land area (land cover). A good example would be to plot population density over a coastal city. What is a good approach for this, when it comes to the data source and how to actually display layers with such detailed boundaries?
Technically, so far I'm using Leaflet.js and tiles based on OpenStreetMaps, but the question is not necessary technology specific. Also, I'm not interested in plotting this for the whole planet, but for areas of a few hundreds square kilometers (for e.g. a coastal city).
To better give an idea of what I'm interested in, this Koordinates map is something that is similar to what I'm interested in. However, I need something a bit more detailed on the borders.
Usually you need a desktop or server based GIS such coverage, but not JS to do the processing on the client side.
How you do the mapping (here: linking statistical data and land areas) depends on your data itself. You can load OSM based shape files into QGIS and do some python scripting or using the PostGIS commands to link your data and choose a map style.
Another idea would be http://geocommons.com that allow easy visualization if you upload CSV files.
Depending on your area of interest, you can obtain some highly detailed shapefiles from numerous sources. Especially if the local area provides GIS data to the public (many larger coastal cities do, e.g. New York, London). From there, you can create a GeoJSON text of the geometries (here's a free tool for that). Parsing the JSON is very simple and it's very easy to add it to leaflet maps. You can even get creative and add more keys to each geometry object with the data you want to visualize.
We are creating a speed limit map application using different colors to highlight street with different speed limits (similar to ITO speed limit map: http://www.itoworld.com/map/124?lon=-79.37151&lat=43.74796&zoom=12).
The problem we have is that we are conducting our own research and have our own speed limit data instead of pulling the data from OpenStreetMap or Google Map like ITO map. We also need to create a data storage in order to dynamically update the map as we add more speed limit information in the future.
Is there anyway to create our own instance of OpenStreetMap and replace only the speed limit information with our own data? We don't have any vector data and we have no experience working with them.
Is there any suggestion of tools to use for creating highlighting layers based on the speed limit we have? Is OpenLayers a good option?
Any help is appreciated, thank you very much.
Update 2013/11/20
Thank you very much for your answers, now we have a much better understanding of your problem. This is a university design project so we basically have no budget. We are looking for:
1) A basic "base map" that include the basic tile information (openstreetmap seems a good choice since google map api doesn't provide free road information as long as we can find)
2) A geo data server that can host our own street speed limit data (looks like geoserver and mapserver are good choices), or a design simple database that can fulfill our need(doesn't know is it possible yet)
3) A plotting tool that can render our speed limit data as "group of lines" on the map since these data will be changed frequently (openlayers and leaflet are good candidates).
Is there anything else needed?
What you want to do is a trivial programming task once you have decided a few things:
These are probably the three biggest questions you need to answer. I added some commentary, but look at each of these questions beyond this post to find what works for you.
Who do you want to use for your map? Since you only have one type of data you will want to display that data on someone else's nice looking map. The big choices are Bing, Google, OpenLayers/OSM, and ESRI. Your choice will most likely be driven by the licensing of the above services and if you are willing to pay or not. A need to support mobile devices may also factor into your decision. Since the map is what your users will see, choose the best looking map you can afford.
How will you serve up your data? You have several options to serve your speed limit data. GeoServer and MapServer and ESRI are some popular mapping software packages. If you only displaying a few layers of data all mapping software will be overkill. The actual software to render your map data will most likely affect only your pocket book, so free is good here usually.
Tiles vs Lines
You will server your data as either a group of lines sent to the browser, or as pre-rendered tiles to be loaded on top of the map. If you data changes frequently you will want to serve it dynamically as line data (an array of points.) If your data does not change frequently, you should consider tiling your data. Tiling involves pre-rending of the entire map at all zoom levels. This allows the map to be loaded very fast and this how almost all base maps are rendered. The downside is that the tile generation can take a long amount of time and tiles can take a large amount of space.
This is a very broad question. There are many components to drawing your own speed limit map.
On the front-end, there is a web browser map interface. OpenLayers is good at that. There are plenty of other tools that can do this as well, such as Leaflet or even Google Maps API.
Next is something to provide the actual speed limit route data. This can be served as a vector layer or a raster layer. There are plenty of tools here, too. UMN Mapserver is free and reasonably good. ESRI makes a whole fleet of products in this area as well.
The speed limit route data also needs to be saved somehow. This can be done in files or in a database such as PostGIS. Again, lots of great options.
It is the role of the system architect to determine which technologies to employ to solve the problem.
I would like to have the possibility to tell if a GPS location is in an inhabited or uninhabited zone.
I have tried some reverse geocoding services out there, but all of them proved useless, because they select the nearest address possible. (I understand why this should be so, it is useful for the purpose of reverse geocoding)
I have noticed in Google Maps, when I search for a city, their boundaries are selected in red dotted well defined line. I would love it to use this, or something similar.
Is there any possible way that Google maps can provide such a service, or something that can solve my problem.
Are there any other web solution or databases that you know of that can give me this information ?
Or maybe I can use any of the reverse geocoding solutions with some parameters (such as restricting the size of searching) to determine if the location is or is not in a populated area?
If you will not find a public service then it gets interesting, and expensive in terms of developping effort.
Public data (world wide) is only available from OpenStreetMap, i think they have such a layer (could be named Land_use (rural, etc.)) This layer is usually used to color a map, look at openstreet map Web page if you find a suitable coloring, that coresponds to your task. (E.g look at green, or gray).
These data are stored in polygons, you would have top extract these polygons (i asume millions of them). Ten you need a fast searching spatial index, like a region Quadtree.
Then you do a "point(lat, lon) in polygon" call, and get the polygon related to your position.
Probaly not all that polygons will fit into main memory, so you must load them on demand (e.g by country).
A variant of this approach is to use a geo spatial database like postgres to store that polygons, and do a DB query.
With that approach most work will be extracting the polygons from OpenStreetMap DB file.
More acurate is data from TomTom, but these can be really expensive.
I have data that I want to create a GIS type application that will have the typical features of adding and removing layers of different types. What is the best architectural approach?
The data consists of property locations in Eastings and Northings.
I also have ordnance survey data in GML and Shapefiles.
I know this is a very broad question but the subject area also seems very broad to me and I am unsure which direction to go.
I was thinking of using SQL 2008 spatial and Bing Silverlight control to visualise that maps.To do this would I have to convert the eastings and northings to GWS84 geography datatype? But then if I converted the shapefiles to GML and imported all the GML files to sql using GeomFromGML they would be in geometry datatypes. Wouldn’t the two types be incompatible?
Also, should ESRI ArcGIS API for Silverlight
feature in the equation? Is this a good environment to create maps that I can point as SQL sqerver 2008 as the datasource (using a WCF service if necessary)?
Any advice greatly appreciated!
This is something I've done several times, using OS data from SQL Server in both Bing Maps AJAX and Silverlight controls. Some general comments below (in no particular order!):
Don't expect to implement full-blown
GIS functionality using Bing Maps.
Simple querying, retrieval and
display of the data is all fine (+
some simple editing), but after that
you'll be struggling with what can be
achieved in the browser.
All vector shapes supplied to Bing Maps need to be in (geography)
WGS85 coordinates, EPSG:4326.
However, all data will be projected
and displayed using (projected)
Spherical Mercator system, EPSG:3857.
In terms of vector shapes, you can expect to achieve a similar level of performance as you get in the SSMS spatial results tab - that is, (with careful architecture) you can plot up to about 5,000 features on the map at once, zoom / pan around them, click on them to bring up various properties and attributes etc. However, after that you'll find the UI becomes fairly unresponsive (which
I imagine is the reason why the spatial results tabs itself limits you to displaying 5,000 records at once).
If you want to display more features than this, one approach is to rasterize them by projecting them into the EPSG:3857 projection, creating a .PNG/.JPG image file of the features and then cutting that image into tiles according to the Bing Maps quadkey tile numbering system as explained here:
http://msdn.microsoft.com/en-us/library/bb259689.aspx and displaying them as a tilelayer. Tile layers are significantly faster than displaying the equivalent vector shapes, although it means the data is static.
If you do create raster tiles, you can either render them dynamically
or pre-render them to improve performance - i.e. you could set
up a job to render and update the tileset for slowly-changing data
every night/every month etc.
If you're talking about OS Mastermap data, the sheer level of detail
involved means that you need to think more carefully about what
features you want to display, and how you want to display them. Take
greater London, for example, which covers an area about 50km x 40km. To
create raster tiles (each of which are 256px x 256px) at zoom level 19
covering this area you'd need to render and store 1.3 million separate
tiles. If each of those is generated from a database query that takes, say
200ms to run, it's gonna take a looooonggggg time to prepare all your
data. Also, once the files have been generated, you might want to think
about storing them in a DB rather than saving them on a file system.
As for loading the OS data into SQL Server in the first place - there
are several tools that will import either from GML or shapefile into SQL
Server, and handle the projection from EPSG:27700 (Ordnance Survey
National Grid) to WGS84 along the way. Try GDAL/OGR or Safe FME for
starters.
I have a blog at http://alastaira.wordpress.com that has several blog posts that you may find useful describing various aspects of integrating Bing Maps and SQL Server. Particularly, you might want to look at:
http://alastaira.wordpress.com/2011/02/16/loading-ordnance-survey-open-data-into-sql-server-2008/
http://alastaira.wordpress.com/2011/01/23/the-google-maps-bing-maps-spherical-mercator-projection/
http://alastaira.wordpress.com/2011/02/21/using-ogr2ogr-to-convert-reproject-and-load-spatial-data-to-sql-server/
I have an application that draws a vector map of the 50 United States. Each state is a polygon. These polygons change color as the state of the application changes.
I obtained the coordinates I'm using now by laboriously tracing a scanned in map with a mouse, recording the screen coordinates as I did so. As you can imagine my vector map is pretty ragged. I'd like improve the appearance of my maps by using real boundary coordinates for each state, and in the future use other political boundaries in my app such as counties or congressional districts.
I know nothing about GIS systems, nothing at all. I do think that given a vector of lat/long pairs for the borders of each political entity I could convert the lat/longs into screen coordinates. I used to be an Air Force navigator, so I'm comfortable with lat/long calculations.
Bottom line: I need an open source or public GIS database system that could spit out a list of Lat/Long pairs for the boundaries of the fifty States.
Can someone provide a pointer to such a database and hopefully a tutorial of some kind describing how to extract political boundary information from it?
Thanks in advance!
The Census Bureau provides the TIGER data sets that include shapefiles for state outlines (and much, much, more). The downloads are in ESRI Shapefile format, which can be opened by most GIS applications, such as the easy to use open-source QuantumGIS. To convert the shapefiles to a format that's easier to work with, see this question. Once you've got the vector data into your program, you'll probably realize that it's more detailed than you want. Check gis.stackexchange.com for some tools to simplify the polygon outlines. Once you've got the sets of points you want, you may want to use the PROJ library to handle the projection of the points on to your map.