Call for Proposals, Presentations and Workshops: Free and Open Source Software for Geospatial 2015, Burlington, CA

FOSS4G North America will be hosted from March 9th to 12th, 2015 at the Hyatt Regency in Burlingame, California. This gorgeous venue is close to the San Francisco Airport and offers many quiet places to sit down and talk with friends and colleagues in addition to the great session rooms.
The deadline for the call for papers is today, Monday, November 17th.

Submit a presentation or workshop now.
Accepted speakers receive a free full access pass to the entire conference!

See which talks are already accepted.
FOSS4G NA 2015 is co-hosted with EclipseCon, and a PostgreSQL event.

Attend any talk or workshop for one low price.
FOSS4G North America is a collaborative event by OSGeo & LocationTech, organized by the Eclipse Foundation.

Register before December 31, 2014 and save!



Tips to share a leaflet map with multiple ROIs

Do you have a Leaflet map? Yes. Can you panned and and zoomed to a particular event or ROI in the map? Yes. Then, how can you share that map zoomed or centered with ROI/events to your webpage or email as a link? One of the answers may be set the zoom level and set view near the ROI.  Alright, what will you do if you have a map with multiple ROI/events? Do you make multiple maps with multiple zoom level and view? You can, but probably not a good idea to do that. 

The solution comes here, leaflet-hash.js, solves your needs, it is a JavaScript library written by Michael Lawrence Evans, which appends the URL hashes to web pages automatically and the hash changes with Leaflet map on drag or zoom. The hash consists of map zoom level and latitude/longitude of the center of map viewport, everything you need to share the map with focused ROI as link in following simple steps:

jQuery mobile swipping the contents

Snippets on jQuery mobile swipping the contents:

 //HTML  
 <div data-role="content" id="content1"></div>  
 <div data-role="content" id="content2"></div>  
 <div data-role="content" id="content3"></div> 
 
 //JQ script  
 $(document).one('pagebeforecreate',function(){  
 $("div[data-role='content']").bind('swipeleft', function(e){  
           var next=$(this).next("div[data-role='content']");  
           e.stopImmediatePropagation();  
           console.log(next);  
           return false;  
      }); 
 
 $("div[data-role='content']").bind('swiperight', function(e){  
      var perv=$(this).prev("div[data-role='content']");  
           e.stopImmediatePropagation();  
           console.log(perv);  
           return false;  
      });  
 )}  

How to display the MesoWest weather stations in Leaflet.js?

Snippet to display MesoWest weather stations in Leaflet.
 //Hold markers group  
 var mesoMarkersGroup=new L.LayerGroup();   
 //Get weather information from Mesowest for the state VA  
 $.getJSON('http://api.mesowest.net/stations?callback=?',  
      {  
           state:'va',                   
           latestobs:1,  
           token:'demoToken'  
      },   
      function (data)   
      {  //Loop through all the weather stations  
        for(var i=0;i<data.STATION.length;i++)  
           {  
            try{  
                 var stn = data.STATION[i];  
                 var dat = stn.OBSERVATIONS;  
                 var stnInfo =stn.NAME.toUpperCase();  
                 var elev=parseInt(stn.ELEVATION);            
                 stnInfo = "<b>Air Temp:&nbsp;</b>"+Math.round(dat.air_temp[1])+"&deg;F"+ "</br><b>Wind Speed:&nbsp;</b>"+Math.round(dat.wind_speed[1]* 1.150)+"MPH"+"</br>  
                 +<b>Wind Direction:&nbsp;</b>"+getCardinalDirection(Math.round(dat.wind_direction[1]))+"</br><b>Relative Humidity:&nbsp;</b>"+dat.relative_humidity[1]+"%"+"</br>  
                 +<b>Elevation:&nbsp;</b>"+elev+"&prime;";       
                 //Add stations into Leaflet markers group  
                 L.marker(L.latLng(stn.LATITUDE,stn.LONGITUDE),{title:stn.NAME.toUpperCase()}).bindPopup(stnInfo).addTo(mesoMarkersGroup);  
            }    
            catch(e)  
            {  
                alert("Error! "+ e);  
            }  
           }   
  })       
 .done(function()  
 {  
 })  
 .fail(function()  
 {       
      alert("Could not access the MesoWest!");  
 });  
 //Add markers group to the Map  
 map.addLayer(mesoMarkersGroup);  

Where are my streets Chrome? Google Maps bug on Chrome or vice-versa

I was checking the route for nearest police station from my office around 3 PM MT using the Chrome. The  Google Map's street looks so funny and floppy. All the street lines and highways lines were wiped out. The interstate has some brown points, if you zoom in them the point looks like half circle. Which has the bug Google Maps or Chrome? Click on images for bigger picture !

(Missing roads)

                                                                 (Missing roads on zoom)

                                                                         (More zoom in...)
(Looks good in  the Firefox though)

The Manager's Guide to PostGIS - Paul Ramsey at FOOSS4G 2014 PDX

Interesting talk by Paul Ramsey about the decision process to adopt PostGIS vs other spatial databases at FOOSS4G 2014 Portland, OR. Ramsey, "what do managers need to know before they can get comfortable with the idea of making the move."

National Geodetic Survey plans to release future Geodetic Datums in 2022

National Geodetic Survey (NGS) developed videos to give you a better understanding of NGS' plans to release new datums in 2022. If you use mapping products or other geo-spatial tools, these videos should also help you find out how you can prepare for the new datums. . It’s a number of years off - but the links explain the changes and provide some initial knowledge that may help you prepare for their advent…

This series of short videos, produced in collaboration between NOAA's National Geodetic Survey and The COMET Program, a part of UCAR's Community Programs, provides an introduction to geodetic datums for anyone who uses mapping products or other geo-spatial tools.

 In the first video, "What are Geodetic Datums?" (4:36), explains the basic concepts behind geodetic datums, where they are used, and why it is important to know about and use the correct datums.


Leaflet TypeError: t is null

There are may be several reasons for TypeError:t is null, but I solved my problem by changing-
 L.marker(LATITUDE,LONGITUDE).bindPopup("Info").addTo(map);  
 to  
 L.marker(L.latLng(LATITUDE,LONGITUDE)).bindPopup("Info").addTo(map);  

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