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1500 questions
21
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3 answers

Downloadable, Open Source, IP GeoLocation database

I have an open source project. I need a similarly open source IP GeoLocation database i.e. IP address to country (and ideally city). Ideally with a license that allows redistribution. This is a question that's been asked before (Advice on geocoding…
GIS-Jonathan
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Fixing orphaned holes in R

I'm trying to perform a union on a common field after merging two adjacent shapefiles. The shapefiles end up with at least one thin sliver of space between them. When I attempt a union I get the following orphaned hole error: Error in…
Luke Macaulay
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21
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3 answers

Reverse clipping (erasing ) in R?

A reverse clip saves only the part of your spatial object that is outside the bounds of another object, as opposed to a regular clip which saves the parts that are inside the other object. Performing reverse clip in ArcMap? shows how to do it in…
RobinLovelace
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21
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1 answer

Advantages of R-trees in comparison to geohashes

Geohashes are being widely used in products like: Lucene, mongodb, etc and have become one of the most important technology of present day. Have Geohashes replaced the good old R-trees or do R-trees have any advantages as compared to Geohashes?
Jannat Arora
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20
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6 answers

Increasing developer productivity with ArcGIS platform?

We are a small team of .NET developers. We have ample GIS experience, and none of us are new to software/database development or system administration. We have technical degrees and many years of industry experience. We have attended Esri Developer…
nw1
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20
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8 answers

How can I determine the location of a visitor to my website?

If I want to provide a website with location appropriate content, what ways can I use to find the visitor's rough location using their IP or header information?
JamesRyan
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20
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2 answers

How do GPS/Glonass/Galileo satellite know their position?

We use satellites to calculate our position. How do satellites know their position if it is right or wrong ? I have heard that the base station records and corrects the satellite path but how do they know what is right path what is wrong path ?
Abhijit Gujar
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20
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3 answers

Looking for an "introduction to photogrammetry" book with a well documented chapter on UAV

I would like to recommend a book for my students to learn the basis of photogrammetry. I've read "Introduction to modern photogrammetry", 2001, from Mikhaïl, Bethel and McGlone. Unfortunately, the field has evolved a lot since 2001. I've found only…
radouxju
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20
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1 answer

Finding Nearest Line Segments to Point using shapely?

Background From a known Point, I require to establish the nearest surrounding "visible perimeter" against a table of MultiLineStrings, as shown on the diagram. I've searched this site with a number of terms (e.g. minimum edge, minimum perimeter,…
Rusty Magoo
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20
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2 answers

How to make RASTER from irregular point data without interpolation

I was trying to make a raster image from an irregularly spaced point database. The data looks like- > head(s100_ras) x y z 1 267573.9 2633781 213.29545 2 262224.4 2633781 69.78261 3 263742.7 2633781 51.21951 4 259328.4…
ToNoY
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20
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4 answers

What python web-mapping framework to use?

I am interested in developing a web-mapping application. I am relatively familiar with Python and so i'm looking for a python framework. What are my options? what are the pros and cons of each option? I am looking for a simple option, one that…
vagvaf
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20
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8 answers

How to convert raster to point in QGIS

I wanted to convert Raster into Point Vector in QGIS. Is it possible? QGIS have option to convert it into polygon but i didn't found any tool to convert it into point. can anyone help me?
suyogpatwardhan
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20
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2 answers

What is the most common way of displaying geodata from Postgis on Leaflet?

For example, in my database I've some points with geographic coordinates. I want to display them on Leaflet JS layer. Which instruments should I use? Maybe there is some API...
John Smith
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20
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1 answer

Why do people pronounce GDAL (Geospatial Data Abstraction Library) like goo-dal?

Ok, a bit of a silly question, but: I've heard people pronouncing the library GDAL (Geospatial Data Abstraction Library) like goooo-dal. My natural inclination was to pronounce it geeee-dal, as in the letter 'g'-dal. Any explanation on how…
bcollins
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20
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5 answers

Explanations for Various GIS Job Titles

I've been out of school and working in the GIS field (mostly the field of a desk) for over five years now. The one consistency I've found when working for various companies and applying for various jobs is that there is no consistency in the way our…
Cody Brown
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