## Friday, December 5, 2014

### Highly popular Lidar vocabularies

A
accuracy The closeness of an estimated value (for example, measured or computed) to a standard or accepted (true) value of a particular quantity. See precision.

absolute accuracy A measure that accounts for all systematic and random errors in a dataset. Absolute accuracy is stated with respect to a defined datum or reference system.

accuracyr (ACCr) The National Standards for Spatial Data Accuracy (NSSDA) (Federal Geographic Data Committee, 1998) reporting standard in the horizontal component that equals the radius of a circle of uncertainty, such that the true or theoretical horizontal location of the point falls within that circle 95 percent of the time. ACCRMSErr=×17308..

accuracyz (ACCz) The NSSDA reporting standard in the vertical component that equals the linear uncertainty value, such that the true or theoretical vertical location of the point falls within that linear uncertainty value 95 percent of the time. ACCRMSEzz=×19600..

horizontal accuracy The horizontal (radial) component of the positional accuracy of a dataset with respect to a horizontal datum, at a specified confidence level. See accuracyr.

local accuracy The uncertainty in the coordinates of points with respect to coordinates of other directly connected, adjacent points at the 95-percent confidence level.

network accuracy The uncertainty in the coordinates of mapped points with respect to the geodetic datum at the 95-percent confidence level.

positional accuracy The accuracy at the 95-percent confidence level of the position of features, including horizontal and vertical positions, with respect to horizontal and vertical datums.

relative accuracy A measure of variation in point-to-point accuracy in a data set. In lidar, this term may also specifically mean the positional agreement between points within a swath, adjacent swaths within a lift, adjacent lifts within a project, or between adjacent projects.

vertical accuracy The measure of the positional accuracy of a data set with respect to a specified vertical datum, at a specified confidence level or percentile. See accuracyz.
aggregate nominal pulse density (ANPD) A variant of nominal pulse density that expresses the total expected or actual density of pulses occurring in a specified unit area resulting from multiple passes of the light detection and ranging (lidar) instrument, or a single pass of a platform with multiple lidar instruments, over the same target area. In all other respects, ANPD is identical to nominal pulse density (NPD). In single coverage collection, ANPD and NPD will be equal. See aggregate nominal pulse spacing, nominal pulse density, nominal pulse spacing.
aggregate nominal pulse spacing (ANPS) A variant of nominal pulse spacing that expresses the typical or average lateral distance between pulses in a lidar dataset resulting from multiple passes of the lidar instrument, or a single pass of a platform with multiple lidar instruments, over the same target area. In all other respects, ANPS is identical to nominal pulse spacing
18 Lidar Base Specification
(NPS). In single coverage collections, ANPS and NPS will be equal. See aggregate nominal pulse density, nominal pulse density, nominal pulse spacing.
artifacts An inaccurate observation, effect, or result, especially one resulting from the technology used in scientific investigation or from experimental error. In bare-earth elevation models, artifacts are detectable surface remnants of buildings, trees, towers, telephone poles or other elevated features; also, detectable artificial anomalies that are introduced to a surface model by way of system specific collection or processing techniques. For example, corn-row effects of profile collection, star and ramp effects from multidirectional contour interpolation, or detectable triangular facets caused when vegetation canopies are removed from lidar data.
attitude The position of a body defined by the angles between the axes of the coordinate system of the body and the axes of an external coordinate system. In photogrammetry, the attitude is the angular orientation of a camera (roll, pitch, yaw), or of the photograph taken with that camera, with respect to some external reference system. With lidar, the attitude is normally defined as the roll, pitch and heading of the instrument at the instant an active pulse is emitted from the sensor.

## Tuesday, November 25, 2014

### Solution: IntelliJ not recognizing a particular file correctly, instead its stuck as a text file

I had mistakenly save my class as fileName.text file and tried to rename it with fileName .java but the IntelliJ couldn't recognize it and throws the error saying..
After spending long hours on internet, I found a solution and sharing/keeping here for future reference.

Step 1: Click "File"==> "Settings"
Step 2: Expand "Editor" & Click "File Types"
Step 3: You will see all file types on Right. Navigate to the "Text Files" and Click it
Step 4: You should able to see your file name on the bottom of Registered Patterns (lower box)
Step 5: Remove your file from the Registered Patterns. The problem should solved and let you to rename with fileName.java
Step 6: If not, delete the file from the project and create it again with name fileName

### Get PDF fonts information line by line using PDFBox API

Sample code snippet on extracting font information line by line using PDFBox API in JAVA.

`````` public String[] getFontLineByLineFromPdf(String fileName)throws IOException
{
PDFTextStripper stripper = new PDFTextStripper() {
String prevBaseFont = "";
protected void writeString(String text, List<TextPosition> textPositions) throws IOException
{
StringBuilder builder = new StringBuilder();
for (TextPosition position : textPositions)
{
String baseFont = position.getFont().getBaseFont();
if (baseFont != null && !baseFont.equals(prevBaseFont))
{
builder.append('[').append(baseFont).append(']');
prevBaseFont = baseFont;
}
builder.append(position.getCharacter());
}
writeString(builder.toString());
}
};
String content=stripper.getText(doc);
doc.close();
String pdfLinesWithFont[]= content.split("\\r?\\n");
return pdfLinesWithFont;
}
``````

## Monday, November 17, 2014

### 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!

## Friday, November 7, 2014

### 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:

## Monday, October 20, 2014

### 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;
});
)}  ``````

## Thursday, September 18, 2014

### 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
}
catch(e)
{
}
}
})
.done(function()
{
})
.fail(function()
{
});
//Add markers group to the Map
``````

### 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 !

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

## Wednesday, September 17, 2014

### 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."

## Sunday, August 31, 2014

### 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.

## Friday, August 29, 2014

### 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
``````

## Tuesday, August 26, 2014

### Job Title: GIS Parcel Maintenance & Election Systems Tech

Job Summary:
Incumbent provides general and technical support services as necessary for maintenance and support of the Scott County Geographic Information Systems (GIS). Primary responsibilities include the following for GIS: updating digital cadastral database, editing existing parcels, mapping new subdivisions and surveys, providing map production and creation of reports, maintaining spatial datasets and databases. For election systems: maintaining electronic poll books; training election officials on use of electronic poll books; preparing various items of election data for production of ballots and programming of election tabulators and voter assistance terminals.

## Wednesday, August 13, 2014

### Jquery Multiple Range Slider With Floating Points

I was working on a GIS project, which required four range sliders with floating points to set LCLU change threshold. I finally find out a nice jQuery based multiple range slider at http://jsfiddle.net/q5WEe/1/   The compiled fiddle as a web page source is shown in the Part 1.

Then, my goal was to put floating points on the slider bar value display, but the native jQuery slider bar doesn't support the floating point. jQuery always roundup the floating values to the nearest integer. To display the floating point (for example,0.5 break), I multiplied the max  and values with two and divided the display value with two (Part 2) and then I got jQuery slider bar with floating value as below.

## Thursday, April 10, 2014

### New Version of the National Land Cover Database (NLCD 2011) Release :Webinar Announcement

The latest version of the National Land Cover Database (NLCD) for the conterminous United States will be publicly released on April 4, 2014. NLCD 2011 is the most up-to-date and extensive iteration of the National Land Cover Database, the definitive Landsat-based, 30-meter resolution land cover database for the Nation. NLCD 2011 products are completely integrated with those of previous versions (2001, 2006), providing a 10-year record of change for the Nation. Products include 16 classes of land cover, the percent of imperviousness in urban areas, and the percent of tree canopy cover. NLCD is constructed by the 10-member federal interagency Multi-Resolution Land Characteristics (MRLC) Consortium. This seminar will highlight the new features of NLCD 2011 and the related applications.

## Friday, February 28, 2014

### Convert TRRM Real Time Binary File into ESRI ASCII

Seven simple steps for converting TRMM binary to ASCII grid using MATLAB

Step1:
%Open TRMM realtime binary file

trmmFile = fopen('E:\TrmmBinary Processing\3B42RT.2012.03.27.09z.bin', 'rb');

Step2:
%Move file pointer to the begining of  file

frewind(trmmFile);

Step3:
%Read TRMM value from the binary file having 1140 rows and 480 columns

Step4:
%Shift precipitation by 90 degree to relate data with equator

precipitation = rot90(precipitation);

Step5:
%After rotaion by 90 degree ncols changed into 1440 from 480 and nrows
%changed into 480 from 1440

## Tuesday, February 11, 2014

### We will miss the "father of GIS"

Dr. Roger Tomlinson has passed away. Tomlinson is generally recognized as the "father of GIS.” He is the visionary geographer who conceived and developed the first GIS for use by the Canada Land Inventory in the early 1960s.  This and continuing contributions led the Canadian government to give him its highest civilian award, the Order of Canada, in 2001.  Text for that award reads, “he pioneered its uses worldwide to collect, manage, and manipulate geographical data, changing the face of geography as a discipline.”

Tomlinson tells the story of how this came to be.  In the early 1960s he was working as a photo interpreter for Spartan Air Services in Canada.  They had a contract to identify the best location for a tree plantation in Kenya.  They turned to their young geographer Tomlinson and asked him to develop a methodology.  He tried various manual methods for overlaying various environmental, cultural, and economic variables, but all were too costly.  He turned to computers and found the solution.  Subsequently he sold this approach to the Canada Land Inventory that had the responsibility of using data to assist the government in its land use planning activities.  His GIS approach reduced the task from three years and eight million Canadian dollars to several weeks and two million dollars.

He went on to serve the community in many ways.  He chaired the International Geographical Union’s GIS Commission for 12 years, where he pioneered the concepts of worldwide geographical data availability. He is a past president of the Canadian Association of Geographers a recipient of its rare Canadian Award for Service to the Profession.

Other awards followed including the James R. Anderson Medal of Honor for Applied Geography (1995) and the Robert T. Aangeenbrug Distinguished Career Award (2005) from the American Association of Geographers.  He was the first recipient of the Aangeenbrug award and also the first recipient of ESRI’s Lifetime Achievement Award (1997). National Geographic gave him its rare Alexander Graham Bell Award for exceptional contributions to geographic research (2010). He is an Honorary Fellow of the Royal Geographical Society and the recipient of multiple honorary doctorates – in addition to his own PhD from University College London.

### Call for Proposals, Presentations and Workshops: Free and Open Source Software for Geospatial 2014, Portland, Oregon (FOSS4G 10th Anniversary)

FOSS4G (Free and Open Source Software for Geospatial) is pleased to invite proposals for workshops, papers, and presentations for its 2014 conference to be held in Portland, Oregon, USA from September 8th to 13th.

The annual FOSS4G conference is the largest global gathering for all those currently or potentially working with open source geospatial software. It brings together a mix of developers, users, decision makers and observers from a broad spectrum of organizations and fields of operation for six days of workshops, presentations, discussions, and cooperation.

#### Conference Dates

Sep 8th-9th: Workshops
Sep 10th-12th: Main Conference
Sep 13th: Code Sprint

For more information or to keep up to date on news from FOSS4G 2014, follow @foss4g on Twitter, subscribe to our announcements list, or contact: foss4g2014-info@osgeo.org.