OSGeo Planet

From GIS to Remote Sensing: Flood Monitoring Using The Semi-Automatic Classification Plugin

OSGeo Planet - Mon, 2017-01-09 07:28
This tutorial describes a method for monitoring floods using SCP and the freely available images acquired by MODIS and Sentinel-2.Several services provide global monitoring of floods. For instance, the near real-time Global Flood Mapping provided by the NASA Goddard’s Office of Applied Science. This services apply a water detection algorithm to MODIS images, as described at this link . You can find an example of produced map here .Of course, the educational purpose of this tutorial is to monitor flooded areas in a semi-automatic way, exploiting the characteristics of satellite images that can be downloaded with SCP. In particular, MODIS Products allow for the daily monitoring of floods, and the other satellite images (Landsat, Sentinel-2, and ASTER) have higher spatial resolution allowing for more local studies.In this tutorial we are going to study the severe flooding occurred in the Ganges in August 2016, caused by monsoon rains. For more details, please read this informative page by NASA Earth Observatory.

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Tom Kralidis: Cheers to 2016

OSGeo Planet - Mon, 2017-01-09 01:54
It’s been quite awhile since I did one of these, so here goes.  Some notables from 2016: pycsw: the release of 2.0 “Doug” provided the first OGC compliant CSW 3.0 implementation, as well as Python 3 support.  These two major enhancements provide the long term backbone for the project moving into the future GeoHealthCheck: GHC […]
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QGIS Blog: QGIS 3.0 logo voting results

OSGeo Planet - Sun, 2017-01-08 09:48

It is our pleasure to announce that the QGIS.org voting members have unanimously agreed to the adoption of the proposed new logo.

qgis-logo_anita0

We are currently planning the roll out of the new logo to all our applications, web platforms, and social media accounts. In addition, we will create marketing material with the new QGIS branding.  Since this is a volunteer effort, we are planning to approach this step-by-step. The goal is to have everything ready by the time of the QGIS 3.0 release.

If you are interested in helping with this effort, please leave a comment here and we will get in touch!

 


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Jackie Ng: Announcing: mapguide-react-layout 0.7.1

OSGeo Planet - Sat, 2017-01-07 06:25
Here's a quick bug fix release to address the following issues:

The base layer switcher now has a "NONE" option just like its Fusion counterpart


Thanks to some insights from the Blueprint devs, the Accordion component in the Slate and Maroon templates now initially shows the Task Pane when loaded as I had originally intended.

Finally, the scale display dropdown (shown when you have tiled maps) should now properly work when selecting a fractional scale.

Oh, and here's something I left out of the new features for 0.7. The viewer options now actually does something instead of being an empty placeholder. You can use it to toggle feature tooltips on/off should you not have a MapTip present in your toolbar.


Download
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From GIS to Remote Sensing: Webinar by NASA ARSET on Land Cover Classification with Satellite Imagery

OSGeo Planet - Fri, 2017-01-06 10:38
NASA ARSET (Applied Remote Sensing Training) is a program for fostering the acquisition and use of NASA satellite data for supporting decisions, through online webinars and in-person workshops.
In particular, free webinars are available in the following areas: Disasters, Health & Air Quality, Land, Water Resources, and Wildfires.

The upcoming webminar provided by NASA ARSET on Land Cover Classification with Satellite Imagery will cover very interesting objectives such as access and download Landsat imagery and learn the basic steps for performing a supervised classifications using QGIS software.
I am very pleased that the Semi-Automatic Classification Plugin will be used during this training.
This webminar is organized in two dates:

  • Tue, Jan 31, 2017 6:00 PM - 10:00 PM CET: Introduction to Land Cover Classification and QGIS
  • Tue, Feb 7, 2017 6:00 PM - 10:00 PM CET: Improving a Supervised Land Cover Classification

and the Agenda is available here.

Image Credit: NASA/USGS, NASA Earth Observatory
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Ian Turton's Blog: Finding the projection of an unknown set of coordinates

OSGeo Planet - Fri, 2017-01-06 00:00

One of the recurring questions on GIS stackexchange is “I have these points with an unknown projection, can you help?” (at last count more than 100). The answer always depends on if the hapless user knows roughly where they should be. Hint: if you don’t know where your data should be or it’s projection then you have a list of numbers not a spatial data set! The next suggestion is to ask the person or organisation that supplied it (sadly this rarely seems to help).

So to help out with this (apparently) common issue I wrote some GeoTools based code to attempt to find a matching projection.

First it looks up a location using the GeoNames API to get a target point in WGS84. Then we can hunt through the CRS list and pick any which are in the area of validity. Finally we can try transforming the WGS84 point using these possible projections and keep the one which is closest to our unknown point. One small wrinkle is the need to convert the distance to metres (otherwise the ones in feet are always 3 times further away than expected).

The full code is available for you to experiment with here and a pom.xml to build it with.

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Boundless Blog: Using Mapbox Style Objects With OpenLayers

OSGeo Planet - Thu, 2017-01-05 17:08

Boundless has recently released ol-mapbox-style, a utility to use Mapbox’s Style format for styling vector and vector tile layers in OpenLayers. In this blog post, I’ll be showing how to use this new utility. But let’s get started with …

The post Using Mapbox Style Objects With OpenLayers appeared first on Boundless Geo.

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QGIS Blog: Happy new year 2017!

OSGeo Planet - Wed, 2017-01-04 22:34

2016 was an exciting year for us. It was a year with three great releases (2.14 LTR, 2.16 & 2.18), lots of developer and community events (including our 2nd user conference in Girona, the developer meeting in Bonn before FOSS4G & a QGIS Server sprint in Lyon) and many firsts, including the first round of QGIS grants and our new QGIS.org organizational structure.

Group picture from GironaGroup picture from Girona

Many of these initiatives would not be possible without support by our community, dedicated developers and our sponsors, who enable us to keep up our infrastructure and improve software and documentation. We’re particularly proud to welcome three user groups among our top sponsors, with the Swiss user group as our most prominent Gold sponsor:

sponsorsQGIS gold and silver sponsors

Thank you for helping us improve the QGIS experience for everyone!

If you are following this blog, you are already aware that we have even bigger plans for 2017, including but not limited to the big QGIS 3.0 release and a completely overhauled QGIS logo.

We’re looking forward to another great year with the QGIS community.

Keep on QGISing!


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Fernando Quadro: Livro: Desenvolvendo WebMaps

OSGeo Planet - Wed, 2017-01-04 11:39

No final de 2016 foi lançado pelo geógrafo Macos Ummus o livro “Desenvolvendo WebMaps” com o intuito de conduzir qualquer pessoa, em qualquer estágio de conhecimento, a desenvolver webmaps (mapas digitais interativos) a partir da utilização de uma biblioteca JavaScript leve, fácil de utilizar e que apresenta resultados impressionantes: a Biblioteca Leaflet JS.

Assim, se você não possui conhecimento em mapas na internet, este é o seu ponto de partida. Se você já possui algum conhecimento nestas técnicas e tecnologias, este livro também é para você, pois vai te levar adiante. E se você já desenvolve mapas na internet com outras plataformas ou bibliotecas, bom, este livro também é para você, pois vai te apresentar novos caminhos e novas tecnologias: aprender mais nunca é demais.

Apesar de não ter lido o livro ainda, eu recomendo a leitura do trabalho do Marcos, principalmente se você não é da área da tecnologia (Computação e Sistemas de Informação), pois é uma visão de um geógrafo de como programar mapas para web. Vale a leitura.

Fonte: Geotecnologias.org

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Stefano Costa: Total Open Station: a specialised format converter

OSGeo Planet - Tue, 2017-01-03 21:00

It’s 2017 and nine years ago I started writing a set of Python scripts that would become Total Open Station, a humble GPL-licensed tool to download and process data from total station devices. I started from scratch, using the Python standard library and pySerial as best as I could, to create a small but complete program. Under the hood, I’ve been “religiously” following the UNIX philosophy of one tool that does one thing well and that is embodied by the two command line programs that perform the separate steps of:

  1. downloading data via a serial connection
  2. converting the raw data to formats that can be used in GIS or CAD environments

And despite starting as an itch to scratch, I also wanted TOPS to be used by others, to provide something that was absent from the free software world at the time, and that is still unchallenged in that respect. So a basic and ugly graphical interface was created, too. That gives a more streamlined view of the work, and largely increases the number of potential users. Furthermore, TOPS can run not just on Debian, Ubuntu or Fedora, but also on macOS and Windows and it is well known that users of the latter operating systems don’t like too much working from a terminal.

Development has always been slow. After 2011 I had only occasional use for the software myself, no access to a real total station, so my interest shifted towards giving a good architecture to the program and extending the number of formats that can be imported and exported. In the process, this entailed rewriting the internal data structures to allow for more flexibility, such as differentiating between point, line and polygon geometries.

Today, I still find GUI programming out of my league and interests. If I’m going to continue developing TOPS it’s for the satisfaction of crafting a good piece of software, learning new techniques in Python or maybe rewriting entirely in a different programming language. It’s clear that the core feature of TOPS is not being a workstation for survey professionals (since it cannot compete with the existing market of proprietary solutions that come attached to most devices), but rather becoming a polyglot converter, capable of handling dozens of raw data formats and flexibly exporting to good standard formats. Flexibly exporting means that TOPS should have features to filter data, to reproject data based on fixed base points with known coordinates, to create separate output files or layers and so on. Basically, to adapt to many more needs than it does now. From a software perspective, there are a few notable examples that I’ve been looking at for a long time: Sphinx, GPSBabel and Pandoc.

Sphinx is a documentation generator written in Python, the same language I used for TOPS. You write a light markup source, and Sphinx can convert it to several formats like HTML, ePub, LaTeX (and PDF), groff. You can write short manuals, like the one I wrote for TOPS, or entire books. Sphinx accepts many options, mostly from a configuration file, and I took a few lines of code that I liked for handling the internal dictionary (key-value hash) of all input and output formats with conditional import of the selected module (rather than importing all modules that won’t be used). Sphinx is clearly excellent at what it does, even though the similarities with TOPS are not many. After all, TOPS has to deal with many undocumented raw formats while Sphinx has the advantage of only one standard format. Sphinx was originally written by Georg Brandl, one of the best Python developers and a contributor to the standard library, in a highly elegant object-oriented architecture that I’m not able to replicate.

GPSBabel is a venerable and excellent program for GPS data conversion and transfer. It handles dozens of formats in read/write mode and each format has “suboptions” that are specific to it. GPSBabel has also advanced filtering capabilities, it can merge multiple input files and since a few years there is a minimal graphical interface. Furthermore, GPSBabel is integrated in GIS programs like QGIS and can work in a variety of ways thanks to its programmable command line interface. A strong difference with TOPS is that many of the GPS data formats are binary, and that the basic data structures of waypoints, tracks and routes is essentially the same (contrast that with the monster LandXML specification, or the dozens of possible combinations in a Leica GSI file). GPSBabel is written in portable C++, that I can barely read, so anything other than inspiration for the user interface is out of question.

Pandoc is a universal document converter that reads many markup document formats and can convert to a greater number of formats including PDF (via LaTeX), docx, OpenDocument. The baseline format for Pandoc is an enriched Markdown. There are two very interesting features of Pandoc as a source of inspiration for a converter: the internal data representation and the Haskell programming language. The internal representation of the document in Pandoc is an abstract syntax tree that is not necessarily as expressive as the source format (think of all the typography and formatting in a printed document) but it can be serialised to/from JSON and allows filters to work regardless of the input or output format. Haskell is a functional language that I have never programmed, although it lends to creating complex and efficient programs that are easily extended. Pandoc works from the command line and has a myriad of options – it’s also rather common to invoke it from Makefiles or short scripts since one tends to work iteratively on a document. I could see a future version of TOPS being rewritten in Haskell.

Scriptability and mode of use seem both important concepts to keep in mind for a data converter. For total stations, a common workflow is to download raw data, archive the original files and then convert to another format (or even insert directly into a spatial database). With the two programs totalopenstation-cli-connector and totalopenstation-cli-parser such tasks are easily automated in a single master script (or batch procedure) using a timestamp as identifier for the job and the archived files. This means that once the right parameters for your needs are found, downloading, archiving and loading survey data in your working environment is a matter of seconds, with no point-and-click, no icons, no mistakes. Looking at GPSBabel, I wonder whether keeping the two programs separate really makes sense from a UX perspective, as it would be more intuitive to have a single totalopenstation executable. In fact, this dual approach is a direct consequence of the small footprint of totalopenstation-cli-connector, that merely acts as a convenience layer on top of pySerial.

It’s also important to think about maintainability of code: I have little interest in developing the perfect UI for TOPS, all the time spent for development is removed from my spare time (since no one is paying for TOPS) and it would be way more useful if dedicated plugins existed for popular platforms (think QGIS, gvSIG, even ArcGIS supports Python, not to mention CAD software). At this time TOPS supports ten (yes, 10) input formats out of … hundreds, I think (some of which are proprietary, binary formats). Expanding the list of supported formats is the single aim that I see as reasonable and worth of being pursued.

 This post was originally published on the TOPS website
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From GIS to Remote Sensing: Major Update: Semi-Automatic Classification Plugin v. 5.3.0

OSGeo Planet - Tue, 2017-01-03 13:34
This post is about a major update for the Semi-Automatic Classification Plugin for QGIS, version 5.3.0
.

Following the changelog:-added MODIS download and preprocessing tool
-added tool for stacking raster bands
-added MODIS processing and stack bands to Batch tool
-added option to export training input as shapefile
-fixed Sentinel-2 search
-fixed importing spectral signatures
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