Simple Mapping tools: Google Earth, Gemma and Digimap

I'm giving a lecture on Thursday to first year geographers on tools for simple mapping suitable for geography assignments.  My choices?

• Google Earth (well, obviously)
• Gemma (my review on my other blog)
• Digimap

If you step through this prezi presentation to the end you can see:

• My bullet points for the lecture
• To the right of the bullet points for each one I've added some commentary that you have to zoom into to read
• below the bullet points is a YouTube video walkthrough (links Gemma, Digimap) for each one except Google Earth which has a link to an earlier tutorial of mine.  Note that the digimap one assumes you're a Southampton Uni student so can sign into the service.

Prezi maps: You might also like to follow the prezi through, I link to some of my favourite maps and there's commentary on most of them (in the form of the same small scale writing to the right) too.  

Maps and Mapping at University on Prezi

Eye-Tracking Zoomable Maps

This post was joint authored by Paolo Battino and Rich Treves.

One of the evaluation techniques we said we would employ in our Google Research Project (links to search query) is eye-tracking.  Eye-tracking software is usually designed to record the position of your gaze on the screen, assuming the content of the screen only changes in a predictable manner. This means that current eye-tracking software is good for understanding actions on a web page e.g. did the user spend more time looking at side menu, header or main content?  This is because the screen is divided into static areas and the time spent looking at each area can be easily calculated.

Problem with Eye-Tracking: Unfortunately, this does not work with a map (or a virtual globe) and you want to keep track of the geographic location observed by the user.  In this situation, XY coordinates on screen recorded by the eye-tracker do not directly map onto Lat Long coordinates because the user can zoom, pan and tilt the map ‘camera’. 

Solution:  We have developed a solution entirely based on software developed for this project.  See example below:  

    

Heat maps showing density of eye fixations on a Google Earth map.  

Reading down, the screen shots represent zooming in.  

Red = High density, Blue = Low

Subjects were tested in a mock up of an educational situation.  They were shown (in a Google Earth tour) how to identify a special type of valley and then asked to find one in a given area.  The heat-maps show where on the surface of Google Earth the user was looking at during the experiment independent of zoom level/tilt/pan position. 

Heat Map Script: The heat-map script, developed by Patrick Wied, is particularly efficient in showing “the big picture” (top) but also shows dynamic rendering when the user zooms in.  The screen shots themselves are from a Google Map mashup with all the usual zoom and pan controls.

HowTo:  The solution we describe here only works with Google Earth as it requires the Google Earth API.  

Summary of the Process:

1)   During the experiment, the eye-tracker records each fixation in terms of X,Y tuple together with a very accurate timestamp (this is important).

2)   During the experiment, a custom script records the position of the Google Earth ‘camera’ which is producing the view  on screen.  It polls the Google Earth API every 200 milliseconds or so and every entry is timestamped.

3)   After the experiment, on a webpage using the Google Earth API we reproduce exactly the same view displayed during the exercise by feeding Google Earth the logs from  [2].

4)   Using the timestamp of each log entry, we look up the eye-tracking logs to find out if there was a fixation recorded at exactly that time.

5)   We then use the X,Y screen coordinates to poll Google Earth and transform those coordinates into latlongs. In effect we ‘cast’ a ray from a specific location on screen onto the virtual globe.

6)   Using the API we record the lat long from the end of the cast ray and put it into a database (see diagram below)

7)   This data is processed to render the heat-map.

There are obvious far more technical details that this but for the moment we thought we'd just get the idea out.

Problems with Eye-Tracking Maps:  There are a couple of inherent issues to do with eye-tracking virtual globe maps that have already occurred to us:

• High Altitude Zooms:  At both high and low altitude the fixation is captured as a point, at a high zoom the user may be looking at a larger feature.  A circle polygon would better represent the fixation at altitude.
• Tilt inaccuracy: In a situation where the user is highly tilted, the inherent inaccuracies of the eye-tracking kit get amplified - a small change in eye position can represent a large variation in distance on the ground. 

In the particular case study we've discussed today we don't think either of these are a particular issue but they need to borne in mind in other situations.

Cross Section Generator for Google Earth

Today I report on a nifty new tool from Mladen Dordevic of Declan de Paor's team at Old Dominion University for creating cross sections in Google Earth.  Cross sections have many applications from geology, geomorphology, archaeology and even meteorology.  However, putting them in Google Earth has always been a hassle requiring the messy creation of a sketchup model (if, like me, you're not well practiced using that tool) and export into Google Earth.

Screen shot of the tool in action in Hawaii

cross section image taken from here 

The tool:  What Mlarden has created is a tool for taking two images (one for the front, one for the back of a virtual billboard) and putting them back to back.  You get the ability to control yaw, pitch, orientation, height and width of your model (yaw and pitch are really difficult with a sketchup model).  The great thing about putting a cross section in Google Earth is that its in context - users can get a sense of location and scale of the cross section without even having to think about it.  The final step of creation is to generate a .kmz file that can be loaded into Google Earth outside of the API.

But there's more!  That would be more than enough but Mlarden's also cooked in a 'rising block' slider.  This allows for the cross section to be conjoured out of the ground by use of the tour controller once you've published your creation to .kmz.  It's my guess that a significant number of student users never quite grasp that a cross section is from below the ground, by providing a animation slider bottom left of the screen users get reminded of this.

Technical Info and the cloud:  This tool is produced by using the Google Earth API embedded into a web page.  Its a nice example of the power of the API to enable functionality not already in the Google Earth client but it's also 'in the cloud' in the sense that you upload your images and these can be shared with other users.

Bigger Teaching Picture  We could really do with more of these little tools making it easy to create sophisticated, often used elements in Google Earth.  Declan's team has been plugging away at this and when I get some time, I'll be reviewing some more of their work.

UPDATE 4 Nov 2012:  Apologies to both Declan and Mladen for not spelling their names right, now corrected.  

The Power of Street View in Teaching

Streetview is one of the Jewels in the Crown of Google Geo and its a fantastic resource for teaching.  I've just delivered a 'Google Earth as GIS in teaching' session to PGCE students at Southampton University and took the opportunity to polish up my teaching materials, including having another look at what Streetview can do.  I thought I'd share some thoughts on it with you.

Views Beyond the Street: Firstly, it used to just be roads, now they've gone off piste with the streetview trike


and backpack

producing a range of resources including panoramas from the South pole, inside museums and on footpaths.  See the full Gallery.

HowTo:  But before I get carried away with the fun stuff, here's some basic instructions on how to use it in Google Earth looking at a classic Physical Geography field site:  Lulworth Cove.

1] Using the search panel, find Lulworth Cove, UK.

2] Zoom out so you can see the town immediately to the West and the cove in the same view. 

Rollover the controls in the top right of the screen > Click and drag the orange man > Drop him close to the cliff on the blue path between town and cove.   You will be transported into ‘streetview mode’.

3] Look all the way around you and vertically down at the ground by click and dragging the screen

Now ‘walk’ along the road/path by rolling the mouse wheel up and down.  Note that your view stays in one direction

4]  Select a good view, Create a placemark and call it ‘Street View’, click OK.

5]  Now exit streetview by clicking ‘exit streetview’ button, top right.

6]  Double click your new streetview placemark in the places column to fly back into streetview.  

This is handy as you don't have to do all the dragging and dropping of the orange man. 

Teaching Tips - the Cove:  If you're due to go to Lulworth cove, using streetview has obvious uses - you can introduce the site to students and explain where they'll go on the day.  After the trip you can use it to revise what they did and saw, helping them to link the parts of the day to the geography of the site.

The 'constant view' direction that you get with rolling the mouse wheel is particularly useful as you can show them what they will see on the walk out to the edge of the cove.  The direction should be set towards the cove - they shouldn't really be looking elsewhere!

Other Teaching Tips:  I think streetview is very useful not only for physical geography but also for human geography.  I've used it for schools outreach when looking at different neighborhoods, judging income levels depending on how smart the cars and the front doors look.  

You can use it in Google Maps without bothering to use it in Google Earth but I think the advantage of being able to 'tag' locations in streetview with a placemark and return to them at the double click of a mouse is highly useful.

San Francisco Earthquake Teaching Exercise

I've just come across an excellent teaching activity by Noel Jenkins of Juicy Geography about earthquakes in San Francisco using Google Earth.  It uses ground overlays to illustrate areas of liquification danger and earthquake amplification danger. Noel says he's tested the activity in class and that it could be used to cover GIS teaching too.

Opacity Slider:  One of the functions that is used in the activity is the 'opacity slider', this changes the transparancy of a ground overlay.  I thought it worth exactly how to use the opacity slider as its useful in lots of teaching situations:

1] Open the file that goes with the lesson plan

2] Expand the folders in the Places column until you have the data overlays folder open (click the plus buttons on the left of the folders to do this)

3] The elements showing in this folder are all ground overlays, basically images that lie over the Google Earth topography like a table cloth.  You can tell this by looking at their icons in the places column - a sheet overlying another sheet.

4] Tick one so it shows on screen.  Notice that it also goes blue, this means it's selected.

5] Click the square icon at the bottom of the Places column to the right of the magnifying glass.  A slider appears, moving the circle changes the transparency (or opacity) of the overlay.

Adjusting the opacity allows you to see the true image of the ground below and or see another ground overlay more clearly.


Useful Supporting Videos:




the above clip shows someone lecturing at the time of an earthquake (I think in California).  If you replay it and watch carefully you can see that most of the students run for the door and only one student does what they've been taught and dives under the desk.

The clip below shows an illustration of liquefaction, when shaken, the sand behaves like a liquid and more dense items (the building model) will sink into it.  You can easily do something similar with a box of rice which you shake by hand, you don't need the motor shaker.  




and this is what it looks like in real life.  The water coming out is a more complicated effect to explain but is related to liquefaction occurring.

London Olympics Time Tour Teaching Idea

Despite being no fan of athletics normally the London Olympics running in my city hooked me in over the last couple of weeks so I thought I'd do a teaching HowTo as my way of honoring the whole event.

Part of the Olympic Park in London with 3D buildings turned on

Teaching Idea:  In the tour below you can see that you can use a tour to fly back in time as well as flying place to place.  One of the interesting parts of these games has been the regeneration it promises to bring the east end of London so my idea is a little sequence to see the history of the site in 1945 and in the present.

Open the following file in Google Earth and double click the tour in the places column to play it.

     Olympics Time Tour.kmz

Obviously this 'time tour' idea can be applied elsewhere but its very dependent on what historical imagery exists for any place - you have to go and look to see what historical imagery is available for any location (howto video on using historical imagery)

How To:
1]  Fly to London and pick a  high altitude view.  This is used to remind students the location of the site, its all too easy to have students confused about what country/city they are in.

2] Create a placemark (howto if you don't know).  I've used the text   L O N D O N as putting it in capitals with spaces puts over the idea that we're not marking a place here, more a whole area.  Your placemark automatically captures the view on screen at the moment of its creation.

3] Fly in to the Olympic park area (search top left,  may help here).  Pick a view that captures most of the park, then create another placemark.  Call it 'Olympic Park - 2012'.

4]  Now turn on the history feature.  Its a button on the top bar of the screen with a clock and a backwards arrow.  Move the slider that appears top left of your screen to the far right, you should see that you can go back as far as 1945 and that your screen shows a black and white image from this time.

5] Create another placemark and call it 'Olympic Park - 1945'.  Google Earth automatically captures the time if you've used it.

You now have 3 placemarks with 3 associated views.  We want to move between the three views, to do this, find the placemarks in the places column (left of the screen).

Each placemark is made up of a tick box (turns the point on and off), followed by an icon which is then followed by the name.

6] Double click the icon associated with the L O N D O N placemark to be flown to its view.

7]  Now try it with the London 1945 placemark.  If you are not at that location already you will be flown there but Google Earth will also change the imagery so that you see the view at that time.

8]  If you are presenting this to a class you could just double click from high view, to current park view to 1945 view but thats a lot of double clicking.  Better to pre-record it as a tour which we'll do next

9] Create a folder in the Temporary places folder by:
 
   Click 'Temporary places' in the places column > right click > Add > Folder

Call it 'Time tour'

10] One by one, drag your three placemarks into the folder.

11] Now click the video camera button top of the screen, this will start the tour record bar in the bottom left of your screen.  Click the red dot button and Google Earth will record what you do.

12] Tick your three placemarks so they are visible if they are not turned on already.  Double click London, 2012 and 1945 placemarks icons in turn so you are flown between them.

13]  Click the red dot button again to stop recording.  Google Earth will immediately play your tour back to you again, if you are happy with it, click the disk icon and it will save in your places column.

14]  Make sure your new tour is in the 'Time tour' folder.  This folder now contains all the elements you need for your tour to play.  Right click the folder > save as and save it somewhere.  You can now send that file to others who can play your tour.

Its important to put all the placemarks in a folder and save the folder as otherwise they won't show in the tour if someone else opens it.

Simple or Complex Map Icons

Over at my other blog I've just posted a response to a Google IO talk.  In the second half of the post I discuss whether you should use simple symbol icons (e.g. circles) vs picture icons (a simplified icon showing a wolf) which is relevant to Google Earth.