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M4OPS - Technicalities / To create a new Area in M4OPS
« on: 20 April 2017, 07:17:34 »
To add a new Area
  • Decide on the (three letter) Area Code
  • Create a subfolder within OPS with name (Area Code) (Area Name)
  • In M4OPS.json, add an element to the AreasArray
  • FTP M4OPS.json to /ShowMapsDev/
  • FTP (or create) the Area Subfolder in /ShowMapsDev/
  • When tested repeat the FTPs using ShowMaps instead of ShowMapsDev

Suppose we wish to offer a layer group that comprises three tiled raster layers:
  • Layer A
  • Layer B
  • Layer C
We need to:
  • Process each of the three tiled layers as normal, including adding a row for each to LayerDefs_Other.csv, but
    • with donotshow set to TRUE so the layer will NOT be listed as itself in the drop-down
  • Add a new row to LayerDefs_Other.csv for the layer group with all fields as normal (or null), except for
    • the layertype being Group (rather than Tile)
    • the url being a list of layer titles that are to be included in the group, in the format either:
      • comma separated layer titles (eg Layer A,Layer B,Layer C), or
      • an array of quoted layer titles (eg ["Layer A","Layer B","Layer C"])
    • the value of:
      • minx being null (it will be calculated as the minimum value of minx among all the layers in the group)
      • miny, maxx, maxy similarly being null, and calculated
    • the folder being null

Other Mapping things / Londonist
« on: 25 February 2017, 15:01:38 »
The Londonist is about London and everything that happens in it. They provide "everything you need to know about the capital, as well as celebrating the quirks, eccentricities, hidden and surprising bits that make up the alternative side of the city."

Quite a few of the blog posts are about maps, which you can find through this search box.

Google Earth/Maps and My Maps / Boonah One-Place Study
« on: 25 February 2017, 14:56:40 »
Boonah One-Place Study in Australia uses Google My Maps to show Districts and Places of interest.

Current Needs / Visualising historical data
« on: 25 February 2017, 14:51:39 »
sunnylew's blog article Visualising historical data on Google Maps describes how he’d like to create a virtual view of Hethersett (the village where his grandfather was born in Norfolk) using 3D programmes -something that would look like google earth, but would show the village and its fields and buildings as it looked in the Victorian Era.

One of the technologies he has mentioned as being of possible interest is the Blender Game Engine used for making real-time interactive content.

Open Digital Elevation Model (OpenDEM) describes itself as "The Portal for sharing the 3rd Dimension of the earths surface."

They say there are many ways to record the earth´s surface:
  • Aerial photography
  • Remote sensing
  • Microdrones
  • GPS
  • Trachymeter

Sources of Maps and Geographic Datasets / Landsat
« on: 23 February 2017, 20:25:34 »
The Landsat 8 was launched on February 11, 2013, and photographs the world from orbit. The Landsat 8 Data Users Handbook was written in order to provide users with “a basic understanding and associated reference material for the Landsat 8 observatory and its science data products.”

Users can search, view, and download Landsat 8 imagery with a free online web viewer. Each image covers a substantial area, and they cannot be enlarged beyond about 50,000:1, so their use for a OPS is limited.

Commercial Mapping Companies / Axis Maps
« on: 21 February 2017, 11:16:47 »
Axis Maps build custom interactive maps made up of data, design and code. They also offer a free service - indiemapper - which "helps you make static, thematic maps from geographic data by bringing the best of traditional cartographic design to internet map-making".

Other Mapping things / Blueshift
« on: 21 February 2017, 11:10:20 »
Blueshift enable you to "design and publish dynamic maps in minutes – no coding required".  The example on their website shows migrations from 1820 to 2013.

Mapping Technologies we can probably ignore / MapServe
« on: 21 February 2017, 10:39:21 »
MapServe, and their sister site for consumers BuyaPlan, offer large scale modern UK maps for sale - largely for planning purposes. In PDF, PNG or formats suitable for CAD, none are georeferenced, or as cheap as we can get elsewhere.

The District of Columbia GIS community (including Washington DC) "wants to ensure the District’s data is as open, discoverable and usable as possible". To help with this the District of Columbia Open Data website hosts many sources of geographic data for the area.

Sources of Maps and Geographic Datasets / NextGIS
« on: 20 February 2017, 15:51:10 »
NextGIS, which started in Russia, offer GIS services and products.

With an emphasis on open-source software, they also host a catalog of open source data - Quick Map Services, that is being added to all the time. Formats of data include TMS, WMS, WFS, GeoJSON.

They include plugins to use the data within QGIS and ArcGIS.

Sources of Maps and Geographic Datasets / LiDAR data
« on: 20 February 2017, 14:54:29 »
The article on Restricting Access to National LiDAR: Is it worth it? is interesting, and summarises the situation in some countries. (Thanks to rapidlasso/ who have specialist LiDAR processing tools.

Those that are opening their LiDAR data sets include:For more on the availability of LiDAR data see the Free LIDAR Data Sources List, which mentions, among others:
  • United States
  • France
  • Spain
  • Philippines
  • Australia

Feature Layer Technicalities / Data formats for M4OPS
« on: 24 January 2017, 17:39:17 »
The main data format used internally by M4OPS for its features layers is GeoJSON, which is a version of JSON designed for geographic data. We use the EPSG:4326 CRS, which is the same as Google Maps and many other systems.

There are many other formats in which feature data can be created, such as 'shape files', see eg the Glossary. Most of these can fairly easily be transformed into GeoJson by:
  • asking Peter to do it (and he is happy to do this for now)
  • importing the data into QGIS and saving it as GeoJSON - specifying the EPSG:4326 CRS
  • convert it using a service such as MyGeodata Cloud (free for smaller datasets)

M4OPS has its own conversion utilities to and from CSV, which is designed for simple datasets. As usual please discuss your use with Peter.

Having said all this, it is possible that with users' experience Peter decides to enhance M4OPS to cope with other formats - please ask.

Mapping Technologies we can probably ignore / Maproom
« on: 21 January 2017, 06:02:51 »
Maproom "sell accurate, editable map bases (in SVG vector format) for websites, brochures, books, magazines and apps. Our royalty-free terms allow you to use a map for commercial purposes without any limit on print run or page views."

"Maproom also offers interactive, animated maps, which can be built to your specifications and embedded on your website or app"

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