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Posts Tagged ‘servicio de mapas’

DTM from SRTM? Let’s compare sources using RMSE (Root Mean Square Error) and a gaussian kernell density map

2014/10/29

I guess we all can make a DTM out of many sources but SRTM is one of the most common ones, right?. Then let’s learn from this very simple approach how close we are from the SRTM raw data.

  1. Selecting a not very big representative area to be able to handle it,
  2. exporting raster to polygon (from SRTM 3 arcsec/90m) dataset 1
  3. exporting raster to polygon 30m (our DTM dataset) dataset 2
  4. exporting to POIs 30m (our DTM dataset) dataset 2b
  5. Spatial join POIs dataset 2b vs dataset 1
  6. RMSE
  7. visualizing delta using a density map/gaussian kernell +appropriate symbolization

In yellow we see theres a full correspondence between SRTM and our DTM dataset and in blue there’s a ‘hole’ and in red there’s a ‘mountain’, this means it’s in here where the shift is more important.

This way we can highlight if sources are OK.

It’s simple but it works. How do you like it?. Please feel free to send some feedbak.
(Software used: ArcGIS 10.1, Global Mapper 13.2)

Cheers,
Alberto Concejal
MSc GIS, QC

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density maps parameters

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Spatial join between both DTM datasets

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Density map for highlighting differences between both datasets (ours and SRTM’s)

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RMSE. It’s not too big so there’s need to visualize to find potential bizarre spots

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bizarre DTM heights

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Some of my 3D scenarios

2009/08/16

Barcelona (Spain), Winnipeg (Canada), Las Vegas (USA), Moscow (Russia), Durban (South Africa), Vancouver (Canada) and Tokyo (Japan)… these were some of my Terrain view’s 3D scenarios published by Computamaps, a South African company I worked in not so long ago. By the way it was one of my best professional experiences ever… I enjoyed joining them a lot and It was very difficult leaving them (mainly because of Cynthia’s fruit salads;-)… Miss you guys a lot!!!

Hope you liked them.
Alberto
BA Geography
MSc GIS and Remote Sensing
GIS Technician
albertoconcejal -at -gmail.com

One more 3D building. Avenida de la Vega 28108. Restaurante Asiático SHENG. Madrid, Spain.

2009/08/15

I used to have lunch every thrusday there, at the ‘Restaurante Asiático SHENG’. I strongly recommend you ‘entremeses’ (In China you will find them as ‘dim-sum’) and Cantonese duck or Hong Kong duck (this was slightly spicy thou).  Very good food, very fast service and pretty cheap menu: 10,7 €… ideal for an IT worker!.

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These views were rendered using ‘V-RAY’ for Sketch-up.

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And now, Let’s go to Google Earth!

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(I have modified my kml using a extruded placemark we talked about a few posts ago).
Now Let’s have our business in 3D!!!!!!!!!!!!!!!.
Hope you like it.
Alberto
BA Geography
MSc GIS and Remote Sensing
GIS Technician
albertoconcejal -at -gmail.com

News: Lufthansa Realtime 3D Airtraffic

2009/08/14

I have just read a very interesting item of news. WHITEVOID has just released a 3D visualization engine for monitoring more than 16.000  Lufthansa airplanes in realtime… amazing, isn’t it?.

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You can navigate throughout the world in a 3D 14 meters screen (!) while you filter content and adjust size, speed and any other parameter…

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In addition there’s a 3D audio system that helps you to be absolutely involved in the scenario… I’d love to handle one of those…

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You can see a very interesting video here:

http://www.fubiz.net/2009/06/23/realtime-3d-airtraffic/

Creating and personalizing KML code (placemarks).

2009/08/11

First of all, what is KML?. KML is a file format used to display geographic data in an Earth browser, such as Google Earth, Google Maps, and Google Maps for mobile. You can create KML files to pinpoint locations, add image overlays, and expose rich data in new ways. KML is an international standard maintained by the Open Geospatial Consortium, Inc. (OGC). You can choose wether authoring directly from Google Earth itself or you can try to understand the code and doing it by yourself… You can draw placemarks (using descriptive HTML to personalize them), ground overlays, paths, polygons… Let’s start with the placemark:

-> Simple placemark

<?xml version=”1.0″ encoding=”UTF-8″?>
<kml xmlns=”http://www.opengis.net/kml/2.2″&gt;
  <Placemark>
    <name>Simple placemark</name>
    <description>Attached to the ground. Intelligently places itself
       at the height of the underlying terrain.</description>
    <Point>
      <coordinates>-122.0822035425683,37.42228990140251,0</coordinates>
    </Point>
  </Placemark>
</kml>

simpleplacemark

  • An XML header. This is line 1 in every KML file. No spaces or other characters can appear before this line.
  • A KML namespace declaration. This is line 2 in every KML 2.2 file.
  • A Placemark object that contains the following elements:
    • A name that is used as the label for the Placemark
    • A description that appears in the “balloon” attached to the Placemark
    • A Point that specifies the position of the Placemark on the Earth’s surface (longitude, latitude, and optional altitude)
  • -> Floating placemark

    <?xml version=”1.0″ encoding=”UTF-8″?>
    <kml xmlns=”
    http://www.opengis.net/kml/2.2” xmlns:gx=”http://www.google.com/kml/ext/2.2” xmlns:kml=”http://www.opengis.net/kml/2.2” xmlns:atom=”http://www.w3.org/2005/Atom“>
    <Document>
     <name>Floating placemark.kml</name>
     <Style id=”downArrowIcon”>
      <IconStyle>
       <Icon>
        <href>http://maps.google.com/mapfiles/kml/pal4/icon28.png</href&gt;
       </Icon>
      </IconStyle>
     </Style>
     <Placemark>
      <name>Floating placemark</name>
      <description>Floats a defined distance above the ground.</description>
      <LookAt>
       <longitude>-122.0839597145766</longitude>
       <latitude>37.42222904525232</latitude>
       <altitude>0</altitude>
       <range>500.6566641072245</range>
       <tilt>40.5575073395506</tilt>
       <heading>-148.4122922628044</heading>
      </LookAt>
      <styleUrl>#downArrowIcon</styleUrl>
      <Point>
       <altitudeMode>relativeToGround</altitudeMode>
       <coordinates>-122.084075,37.4220033612141,50</coordinates>
      </Point>
     </Placemark>
    </Document>
    </kml> 

    floatingplacemark

    -> Extruded placemark

    <?xml version=”1.0″ encoding=”UTF-8″?>
    <kml xmlns=”
    http://www.opengis.net/kml/2.2” xmlns:gx=”http://www.google.com/kml/ext/2.2” xmlns:kml=”http://www.opengis.net/kml/2.2” xmlns:atom=”http://www.w3.org/2005/Atom“>
    <Document>
     <name>Extruded placemark.kml</name>
     <Style id=”globeIcon”>
      <IconStyle>
       <Icon>
        <href>http://maps.google.com/mapfiles/kml/pal3/icon19.png</href&gt;
       </Icon>
      </IconStyle>
      <LineStyle>
       <width>2</width>
      </LineStyle>
     </Style>
     <Placemark>
      <name>Extruded placemark</name>
      <description>Tethered to the ground by a customizable
              &quot;tail&quot;</description>
      <LookAt>
       <longitude>-122.0845787421525</longitude>
       <latitude>37.42215078737763</latitude>
       <altitude>0</altitude>
       <range>365.2646606980322</range>
       <tilt>40.55750733918048</tilt>
       <heading>-148.4126684946234</heading>
      </LookAt>
      <styleUrl>#globeIcon</styleUrl>
      <Point>
       <extrude>1</extrude>
       <altitudeMode>relativeToGround</altitudeMode>
       <coordinates>-122.0857667006183,37.42156927867553,50</coordinates>
      </Point>
     </Placemark>
    </Document>
    </kml>

    extrudedplacemark

    If instead of regular <description>

    <description>Attached to the ground. Intelligently places itself
           at the height of the underlying terrain.</description>

    simple

    you use the CDATA element, you can write HTML and avoiding Google Earth from parsing the code incorrectly:

     <description>
            <![CDATA[
              <h1>CDATA Tags are useful!</h1>
              <p><font color=”red”>Text is <i>more readable</i> and
              <b>easier to write</b> when you can avoid using entity
              references.</font></p>
            ]]>
          </description>

     cdata

    News: Capaware, an opensource 3D geographical Multilayer Framework… First steps…

    2009/08/10

    I discovered this project a few months ago and I’ve been following them very close. It’s always very interesting for freelancers and self taught professionals having an opensource 3D framework to start building your own scenaries not needing to pay a big amount of money for a license… I will do my best to upload here my own projects but let me post you this as a starter… Welcome Capaware!!.

    http://www.capaware.org

    capaware

    Capaware! is a framework for developing 3D multilayer geographical worlds.So powerful as it allows execution of applications directly over it, offers a wide range of applications. To have a quick composition of the stage,nothing better than working directly in three dimensions.

    Capaware! allows viewing of large tracts of land with the minimum amount of information necessary to show it. Those parties that are not visible are not processed, so that the processor loads the minimum memory needed at all times.

    Capaware!, which is developed in C++, allows connection to external servers using OGC protocol to obtain data. We can also configure and manage the resource layers and elements that can be displayed on the ground. Capaware! integrates within GPL free software components for its implementation. Specifically these components are:

    •  OpenScenegraph
    •  WxWidgets
    •  Curl
    • Boost

    Capaware_rc1

    Capaware es un software libre, orientado al desarrollo de aplicaciones geográficas multicapa con visualización tridimensional, desarrollado a medias entre la Universidad de Las Palmas y el Instituto Tecnológico de Canarias. Funciona tanto como SDK para desarrolladores, como también una aplicación individual para visualizar información geográfica, conectando a servidores que cumplan los estándares OGC (Open Geospatial Consortium), y que permite insertar elementos 3D sobre el terreno, compartidos por múltiples usuarios.

    Está dirigido tanto a profesionales que necesiten visualizar información geográfica de forma realista, como a desarrolladores que quieran implementar cualquier aplicación gráfica con especial énfasis en la navegación de terrenos (por poner un ejemplo, desde un SIG 3D hasta un videojuego).

    Optimización Servicio Mapas. ArcGIS. ArcSDE

    2009/07/27

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    Creación de Servicio de Mapas. Oracle Spatial.

    2009/07/27

    Antes:

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    Después:

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