Geoinformation Enabling ToolkIT starterkit

May 21, 2018

Geoinformation Enabling ToolkIT starterkit

Share your maps, measurements, and sensors. Easily.

GET-IT allows you to easily share geospatial data on the web with simple actions.

The suite is the first open-source collaborative effort toward the integration of traditional geographic information with observational data.

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DB Browser for SQLite

May 18, 2018

DB Browser for SQLite is a high quality, visual, open source tool to create, design, and edit database files compatible with SQLite.

It is for users and developers wanting to create databases, search, and edit data. It uses a familiar spreadsheet-like interface, and you don’t need to learn complicated SQL commands.

Getting Started With GeoPackage

May 18, 2018

Getting Started With GeoPackage

***** Identifying a GeoPackage *****

GeoPackage is an SQLite Database file with a .gpkg extension. If you are unsure whether a file is an SQLite database, you can use a binary or text editor to view the starting bytes of the file and see if they state SQLite format 3.

***** Opening a GeoPackage *****

There are a number of ways to open a GeoPackage.

  • For using a direct SQL interface, consider DB Browser for SQLite
  • For using a web application, consider using NGA’s application as long as the GeoPackage file isn’t too big
  • For using a desktop application, there are a number of options. We recommend choosing the GeoPackage implementation that is best suited for your operational environment.

The GeoPackage community tries to maintain a list of operational GeoPackage implementations and this list can be found on the implementations page. Additional information on specific products and versions of products that implement GeoPackage can also be found at http://www.opengeospatial.org/resource/products. You can search by specific versions of the GeoPackage standard. Note: Search for all implementing products.

***** Creating a GeoPackage *****

Similarly, if you wish to create a new GeoPackage from scratch or from an existing source file such as a ShapeFile or .csv, below are some suggestions:

  • For using direct SQL access, start with the empty geopackage template
  • For using a desktop application, refer to the implementations list above
  • For using a command line program, consider the GDAL vector and raster utilities
  • This blog post (The section titled “Creating a GeoPackage with Reference Data”) provides an example that describes steps for creating a GeoPackage using ogr2ogr. The post also provides information on how to add the SpatiaLite extension to enable further spatial analysis in SQLite.

***** Checking a GeoPackage *****

Using a direct SQL interface such as DB Browser is the easiest way to check a GeoPackage version. SQLite uses pragma statements to implement non-standard SQL functions. These statements can be executed just like any other SQL statement and where relevant, they return a result set. The two pragmas you need to know are:

  • PRAGMA application_id
    • 1196444487 (the 32-bit integer value of 0x47504B47 or GPKG in ASCII) for GPKG 1.2 and greater
    • 1196437808 (the 32-bit integer value of 0x47503130 or GP10 in ASCII) for GPKG 1.0 or 1.1
  • PRAGMA user_version
    • For versions 1.2 and later, this returns an integer representing the version number in the form MMmmPP (MM = major version, mm = minor version, PP = patch). Therefore 1.2 is 10200.

***** What is in a GeoPackage *****

Like other relational databases, GeoPackages contain a number of tables. These tables fall into two categories, user-defined data tables and metadata tables. GeoPackages contain two mandatory metadata tables, gpkg_contents and gpkg_spatial_ref_sys. The presence of other metadata tables is dictated by the content being stored (see Content Types). The name of the user-defined data table is the primary key for gpkg_contents and generally is a foreign key for content-specific metadata tables.

gpkg_contents

The gpkg_contents table is the table of contents for a GeoPackage. The mandatory columns in this table are:

  • table_name: the actual name of the user-defined data table (this is also the primary key for this table);
  • data_type: the data type, e.g., “tiles”, “features”, “attributes” or some other type provided by an extension;
  • identifier and description: human-readable text (“identifier” is analogous to “title”);
  • last_change: the informational date of last change, in ISO 8601 format (for practical purposes, RFC3339 applies);
  • min_xmin_ymax_x, and max_y: the spatial extents of the content. (This is informational and often used by clients to provide a default view window.);
  • srs_id: spatial reference system (see next subsection).

gpkg_spatial_ref_sys

For content that has spatial reference (including but not limited to tiles and features), each row in contents must reference a coordinate reference system which is stored in the gpkg_spatial_ref_sys table. The mandatory columns in this table are:

  • srs_namedescription: a human readable name and description for the SRS;
  • srs_id: a unique identifier for the SRS; also the primary key for the table;
  • organization: Case-insensitive name of the defining organization e.g., EPSG or epsg;
  • organization_coordsys_id: Numeric ID of the SRS assigned by the organization;
  • definition: Well Known Text definition of the SRS.

At least three rows must be in this table. There must be one row for each of the following srs_id column values:

  • 4326: latitude and longitude coordinates on the WGS84 reference ellipsoid,
  • 0: undefined geographic coordinate reference systems, and
  • -1: undefined Cartesian coordinate reference systems.

However, many more rows that reference other coordinate reference systems (CRSs) are possible. Using CRSs incorrectly is one of the most common ways to break GeoPackage interoperability. When in doubt, discuss CRSs with a geospatial expert to ensure that you are using an appropriate coordinate reference system for your situation.

AURIN Workbench tools

May 14, 2018

AURIN Workbench tools



Creating a Thematic Map


Investigating Multiple Datasets


Walkability: Neighbourhood Analyses


Walkability: Agent Based Models


Analysing Industry Clustering


Health Demonstrator Tool


Polling Booth Data


Building a dataset for external processing


Rapid Urban Analysis

Becoming an AURIN data provider
Data provision Form

 

Walkability: Neighbourhood Analyses

May 14, 2018

Walkability: Neighbourhood Analyses

Through funding from the Australian Urban Research Infrastructure Network (AURIN) an automated open-source tool was created to generate walkability indices at user-specified scales (i.e., suburb, Census Collector District and user-specified road network buffers). The methods in these tools are able to utilise available state and national level geospatial data to create walkability indices for all Australian urban areas.

[ QGIS ] – [ SPATIALITE ] – How create an intersection between layers

May 14, 2018

[ QGIS ] – [ SPATIALITE ] – How create an intersection between layers

 

 

OpenLevelUp! The OpenStretMap indoor viewer

May 12, 2018

OpenLevelUp! The OpenStretMap indoor viewer

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GeoSOM

May 9, 2018

GeoSOM is the attempt to adapt Self-Organizing Maps (SOM) in order to consider the spatial nature of geographic data. This is done by modifying the way that Best Matching Units (BMU) are chosen; switching from an equal consideration of all variables, to a more spatially centered one (x and y pares, for example). That means, units (neurons)that have similar cordinates to the input data are more likely to be considered as BMUs.

Since GeoSOM is an adaptation of general SOM, it is possible to develop the first, based on the later. In particular, the coding of GeoSOM is based on the somtoolbox for Matlab, developed by staff of the Laboratory of Information and Computer Science in the Helsinki University of Technology.

May 6, 2018

USGS – Mineral Resources Online Spatial Data
Interactive maps and downloadable data for regional and global Geology, Geochemistry, Geophysics, and Mineral Resources

When Maps Lie

May 6, 2018

When Maps Lie