RFID Student Monitoring

Thursday, 29 November, 2007

This is an interesting article from Doncaster about monitoring student movement using RFID chips embedded in school badges (I assume washable!). Clearly there are issues relating to surveillance that some are unhappy about and this has to be balanced against the increase in security of children.

Passive systems (i.e. no batteries) have a range of less than 1 m, which means you would need to install readers where ever monitoring was to occur (i.e. at an entrance to a classroom). Which of course means such a system is no different from taking a register in each classroom, except its digital and its automated. At this level it is not surveillance, but monitoring and is a good thing. It means automated processing can immediately flag when students have entered the school (registration) and then when they are missing from a scheduled class.

I think there’ll be plenty more where this is coming from!

ASTER G-DEM

Wednesday, 21 November, 2007

ASTER is an experimental sensor that sits onboard NASA’s Terra platform and is jointly run by NASA and Japan’s Ministry of Economy, Trade and Industry. Whilst it is an experimental instrument, it has provided remarkably good data (14 spectral bands ranging from 15-90m) and has been very reliable (since launch in 1999). In addition to these 14 bands it also has an aft looking sensor for the collection of stereo imagery and subsequent generation of 30m resolution DEMs. This was originally performed manually “as requested” but has now moved to an automated “on demand” service.

Because of the success of the mission, and near-global coverage of stereo data, funding has been found to compile a DEM of (nearly!) the entire globe at a spatial resolution of 30m and 7m vertical accuracy. The project, called ASTER G-DEM is currently in the preliminary preparation stages, with processing due to start in January 2008 and to take a year. The website is quite informative, showing the scope of G-DEM and how it compares to its rivals, in particular SRTM. In fact this page shows ASTER stereo coverage for the world and compares this to SRTM coverage (which is limited to 56S-60N). Also note that ASTER is photogrammetric, whilst SRTM is interferometric. One of the “problems” with the latter is that the sensor is side-looking and therefore you get data “holes” in steep terrain. This is not a particular problem for the vertical ASTER imagery. Some sample data is already available which people can have a look at. This will be distributed as 16-bit (which means integer values and therefore rounded to the nearest metre) TIFFs in 1 degree tiles.

Definitely a project to watch.

ArcGIS SP4

Monday, 19 November, 2007

Well Service Pack 4 is now available, which includes a list of bugs fixed as well as “new” features. And at 176Mb for Desktop thats neh too bad; although the updated help file weighs in at a heftier 379Mb.

TopSat Opportunities for UK HE Staff

Friday, 16 November, 2007

MIMAS maintain an archive of satellite imagery, primarily of the UK, for most UK HE institutions through the Landmap website. They have just announced an agreement with Infoterra Ltd for the acquisition of TopSat imagery.

TopSat is a Qinetiq satellite (as the prime contractor) that was designed by Surrey Satellite Technology Ltd and was jointly funded by the BNSC and MoD. The four key partners are QinetiQ, SSTL, Rutherford Appleton Laboratories and InfoTerra.

Up until 28th February 2008 academics can request specific “tasking” of the satellite, with up to 3 acquisitions per week being performed. This is a great opportunity to acquire both panchromatic (2.9m resolution, 17×17km) and multi-spectral data (RGB, 5.7m resolution, 18×12km) forresearch or teaching purposes.

Animated GIFs and Powerpoint

Tuesday, 13 November, 2007

I wanted to put an animated GIF in to Powerpoint recently and, when imported, it simply showed a blank square. A little bit of Googling later and it would appear that, from Powerpoint2000 onwards, animated GIFs can be viewed (fully animated) in presentation mode only. When in editing mode, they simply show the first frame. Useful to know…

Stem and Leaf Plots

Wednesday, 7 November, 2007

My wife was teaching stem and leaf plots to first year business students recently and wanted to dynamically show how they are built from a raw data set. We use Powerpoint 97 which doesn’t support motion paths, so makes any kind of “real” animation difficult. Open Office’s Impress has a half-hearted approach to motion paths, but they are pre-defined (although please correct me if I’m wrong!). As a result I ended up using the only animation software I have, which is the Flash-based Swish. For a quick effort, the animation works reasonably well.

Interesting factoid of the week: vinegar….

Monday, 5 November, 2007

Vinegar dissolves the glue that holds the eggs of head lice to hair strands, thus making them easier to comb out. You can tell I have children . . . .

Quantum GIS 0.9 Released

Friday, 2 November, 2007

Quantum GIS 0.9 was released last week. Things are getting close to a full “first version” and this update adds support for scripting Python plugins (and, indeed, Python programs that use QGIS libraries). If you haven’t had a go with QGIS it is well worthwhile and makes an admirable companion to GRASS.

Adpative Release (and the spiral of death)

Friday, 2 November, 2007

I have blogged about using Blackboard before and, by large, things have been pain free. I hit a problem recently which should have been (and was!) easy to solve, but turned out to be quite obtuse. I use Respondus to upload multiple choice tests which my remote sensing class have to take on a weekly basis. This works well and, over the two day period the test is available, nearly all the students complete the questions. Occasionally there are good reasons why a student might not take a test which means making it available to them at a later date (there is no credit for the test so it doesn’t matter whether it has already been seen). The “Adaptive Release” facility on Blackboard covers this (and more complex) eventualities so I set up a new rule and … it didn’t work. After trying several combinations I gave up and chatted to our Blackboard people.

Adaptive Release has four sections that look like they all need completion, given the following text:

This content item is visible to all users until a [section] item criteria is created.

It suggests that each section requires completion which, as it turns out, is not the case. Indeed, for my simple scenario I only needed a date and the student IDs to make it available. This then nearly worked except that the date range set up by Respondus for the test overrides the Adaptive Release rule. Once that is removed it then does work correctly. And the spiral of death? Well, I had incorrectly set up the rule so that it entered the mark into, what I thought, was the correct gradebook item. It wasn’t and was actually waiting for a mark to be entered in to that item before it would allow the student to take the test to enter a mark into the item…

As ever, it’s easy when you know how.