Historical street views from Nørrebro, Copenhagen

The Local Historial Society of Nørrebro, Copenhagen, Denmark, has released a map of historical photographs from the neighborhood of Nørrebro. The map is made using the Google Maps API and contains 50+ photos from the 1910s up to the 1970s.

The map makes it easy to find interesting photos from the area and also contains geocoded articles from Wikipedia about places in Nørrebro.

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Google Maps street views

At the O’Reilly Where 2.0 conference this week, Google presented yet another feature addition to Google Maps: Street Views (read the Google LatLong blog for the announcement including a video presentation of Street View).

Cool features include: interactive pan, zoom and navigation with the use of the mouse and full screen viewing mode. Here are some examples of my past hour (yes, it’s really addictive) of “driving” around the streets of San Francisco:

Also seen above to the lower right is an example of the new 2.5D maps in Google Maps.

For direct links to Google Maps of the examples above: Upper left, upper right, lower left, and lower right.

So far only areas in and around Denver, Las Vegas, Miami, New York and San Francisco are covered by Street View, but I’m sure more cities will be included shortly as this is a very valuable addition to the usual aerial photograps and topographic maps.

Via O’Reilly Radar.

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Map your blog with GeoRSS & Google Maps

GeoRSS is a nice format for adding location to RSS feeds—and recently Google Maps was extended with GeoRSS capabilities.

This blog publishes a GeoRSS feed via the GeoPress plugin (see previous post GeoPress) and to illustrate the capabilites I will tag this post with the location coordinates (latitude,longitude) = 37.87,-122.3, which is where I am currently located (for those who wonders how those geographic coordinates translates to a geographic placename, I’m at UC Berkeley in San Francisco’s Bay Area).

Now, to view this blog’s GeoRSS feed in Google Maps , all we have to do is to go to http://maps.google.com/maps?q=http://blog.makemaps.net/rss2

Via O’Reilly Radar.

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GeoPress

Installed GeoPress a plugin for WordPress for easy geocoding of blog posts including the display of maps. GeoPress is free/open source software and uses Google Maps as its data source. In its current version (v2.2) GeoPress only supports a single location to be associated to a blog post—but in the future multiple locations, lines, polygons, and further customization of the map should be possible.

To show an example of the capabilities of GeoPress here is a map of Barcelona, a place I was pleased to visit recently.

Via O’Reilly Radar.

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Google Earth for Linux

Finally, after months of waiting, almost giving up on the thought of a Linux version of the application that brought maps, satellite images and aerial photographs to the masses, it’s here: Google Earth (Release 4 – BETA), now also available for GNU/Linux!

Still in beta version, it’s a bliss to see Google Earth running on my SUSE Linux 9.2 laptop. No longer does one have to consider installing Microsoft Windows just for running Google Earth. All good things come to those who wait.

Besides now being available on all major platforms, the new beta version implements an improved and simplified user interface.

Anyways, gotta go. I have lots of catching up to do in exploring the vast universe of geoinformation in Google Earth.

Via Ogle Earth and Google Earth Blog straight from the Google Geo Developer Day in Mountain View, California.

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New maps for your world clock

For most operating systems an application exists which displays a world map showing where it’s day and night. A quick glimpse on the map lets you know approximately what time of day it is in different places on the Earth, which can be quite useful—especially if you have family or friends in other parts of the world.

Quite often you can select the background image from a suite of maps and satellite images, for example elevation maps, satellite images or bathymetric maps (see figure to the right). In this post I will describe how to obtain, preprocess and install a new satellite image for a world clock application. In this example I will use kworldclock on SUSE Linux 9.2, but the principles apply to similar world clock programs.

1. Data: First we need to acquire some new satellite image. Most software applications displaying global maps use images in the plate carrée projection, which is also the case for kworldclock. Luckily many satellite images and maps in plate carrée projection are freely available on the Internet

I found a recent satellite mosaic made by the European Space Agency ESA based on hundreds of images from the MERIS sensor on board the satellite ENVISAT. The image has a very high spatial resolution and is ideal for for our purpose. Download the image (4.9M jpg).

2. Preprocessing: The image is larger (3002×1501 pixles) than our screen resolution so firstly we resize the image. Here I use image magick’s convert command (my screen is 1400 pixles wide):

convert -scale 1400 globcover_MOSAIC_H.png globcover.jpg

3. Scripting: Now we need to let kworldclock know about out new image. In the kworldclock maps directory (/kde3/share/apps/kworldclock/maps located various places depending on your system (on my box is was under /opt/)) create a new directory for your new theme (You probably need to be root to do this):

mkdir /opt/kde3/share/apps/kworldclock/maps/globcover

Copy your image to this directory and rename it 1400.jpg:

cp globcover.jpg \
/opt/kde3/share/apps/kworldclock/maps/globcover/1400.jpg

Create a theme file globcover.desktop and put it the maps directory:

[Theme]
Name=MERIS Global Cover
Theme=globcover


  

4. Testing: Run kworldclock and your new theme MERIS Global Cover should now be available in the Map Theme menu when right-clicking the map. Shown above to the left is the MERIS Global Cover. To the right is shown a different new map (405K jpg) for kworldclock made using GMT – The Generic Mapping Tools and a simple script.

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Hello World

First post. “Hello World!” is maybe an appropriate exclamation – and what better way to get started than to display some nice maps?

These four maps show the four hemispheres mapped using the Lambert projection. Upper left: the Northern hemisphere, upper right: the Western hemisphere, lower right: the Southern hemisphere, lower left: the Eastern hemisphere.

The maps were generated using GMT — The Generic Mapping Tools, an open source collection of more than 60 tools for generating high quality maps. Being a command line tool, the learning curve of GMT is quite steep, but once conquered, GMT is more flexible than most GUI based map making software. The above maps were made using the following four lines of code:


pscoast -Rg -JA90/0/5c -B5 -W0.25p -G -P -K > world.ps
pscoast -Rg -JA0/-89/5c -B5 -W0.25p-G -X5.2c \
-P -O -K >> world.ps
pscoast -Rg -JA270/0/5c -B5 -W0.25p -G -Y5.2c \
-P -O -K >> world.ps
pscoast -Rg -JA0/89/5c -B5 -W0.25p -G -X-5.2c \
-P -O >> world.ps


R indicates the Region of interest (here: global), J indicates the projection (A for Lambert, then the projection center and map width), B is the border, W is the coastline, G indicates filling of land areas. If you want to know what the rest means, then go have look at the GMT — The Generic Mapping Tools, and maybe install it on your computer. It runs on Linux, Mac, as well as Windows. There are some very illustrative tutorials as well as cook books available to get you started—but do expect a somewhat uphill learning curve.

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