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Aug 17 2011

Kinect for ArcGlobe

Yet another reason to get a Kinect - we can get more exercise while using ArcGIS !

According to this blog post- we can use a Kinect to navigate ArcGlobe:

The Applications Prototype Lab atEsri has just completed a prototype using a Kinect to navigate in ArcGlobe.

To fly forward, the user can raise their right hand. The display will navigate in the direct the right hand is pointing. We call this “superman navigation”. If the left hand is elevated, the display will pivot around a central location on the globe surface. And lastly, if both hands are raised, the screen will zoom in or out as the hands are both together or apart.


Shall we get one?

Jul 18 2011

XBees Again

I think I have fixed the XBees, again, maybe…

I wanted to get our tablet laptop up and running again as a Hexakopter flying machine for the field – especially since I got the new Pentax WG-1 GPS camera in the mail today (I’ll post on that soon).  This laptop had already been running Mikrokopter-Tool v1.74a, allowing us to do 3D waypoint runs, but the XBees were not functioning at all.  I also had it in my head to install a SSD hard drive in this old laptop to give it a new lease on life – what better opportunity to try a fresh setup! 

A quick note to anyone that has found their way here with their own XBee woes, we are using XBee Pro DigiMesh 900 modules.  This post discusses the (hopefully) successful configuration of a pair of XBee Pro 900’s each mounted on an Xbee Explorer USB.  In a previous post, Xbee Solutions?, I suggested that it is necessary to have an Xbee Explorer Regulated on the MK end, but it seems that may not be necessary based on the results described below.

I got all the standard drivers and software installed and running (XCTU and  UART drivers) and plugged in the suspect Xbees.  Windows 7 said it correctly installed the new hardware, but when I opened up MikroKopter Tool I could not get any XBee communication. AAAAAAAH!

Back to the internet, I found this long thread about Xbee problems that offered promise: http://forum.mikrokopter.de/topic-21969.html

Taking from the thread, I set up two XBees on the same machine in two instances of XCTU to be able to effectively range test and compare parameters. Why had I never thought of that!? I read the modem configurations from each unit – mostly noting anything that was other than the default and confirming the baud rates were set correctly.  I quickly noted that the Modem VID numbers were different and read from the help dialog: “Only radio modems with matching VIDs can communicate with each other.”  One XBee was set to the default and another was set to a specific number.  I didn’t remember making this change but decided to set them both to the same number.  The range test was now working perfectly (see post picture).  Back in Mikrokopter Tool I was back in business with wireless telemetry, but I still couldn’t transfer waypoints.  I kept getting that ‘Communication Timeout’ error.

I tried another suggestion from this  post  in the same thread and manually adjusted the Destination Addressing fields on each unit.  I noted the high and low serial numbers for each unit (SL and SH) and manually configured the  high and low destination addresses to point at each other: XBee1 DL = XBee2SL, XBee1DH = XBee2SH, and vice-versa.

I flashed these settings, booted up MikroKopter Tool and was wirelessly transferring waypoints and receiving telemetry with no problems.

Of course, now we just have to see if it’s actually going to work in the field!

Next up: playing with the GPS camera!

Jun 28 2011

Automated terrestrial multispectral scanning

3D scanning just keeps getting better (but not cheaper!).

A post from Engadget: Topcon's IP-S2 Lite (~$300K) creates panoramic maps in 3D, spots every bump in the road (video) http://www.engadget.com/2011/06/28/topcons-ip-s2-lite-creates-panoramic-maps-in-3d-spots-every-bu/.

More from Topcon:




In China recently, we had the good fortune to collaborate in using a wonderful new ground-based (terrestrial) LiDAR scanner (TLS) from Riegl: The VZ-400, which fuzes LiDAR scans with images acquired from a digital camera (~$140K). Pictured at left- graduate students of the Chinese Academy of Forestry with us in the field- literally!

Feb 25 2011

Photoscan is awesome!

Agisoft’s Photoscansoftware is simply amazing!

The picture at left is an orthorectified photo mosaic over our Knoll research site on the UMBC campus generated by Photoscan automatically using only input photos that I took with the Hexakopter.  For reference, each Hexakopter photo covered less than a 10th of the area observed in this scene. 

An orthophoto is a photo that has been mathematically distorted based on the differences in elevation of the scene so that everything appears ‘flat’, or it appears that the camera was right above each point in the photo.

Photoscan uses similar computer vision technology that Bundler and Photosynth use to automatically recreate the 3D structure of a scene from only photos.

The professional version of the software also makes it very easy to georeference the scene to a geographic coordinate system, making it possible to easily view in a GIS software … or in Google Earth.

Here is a link to a Google Earth image file that Photoscan generated from our photo set, enjoy (35MB kmz file)! 

I am working on getting some 3D output to Google Earth next.

Feb 11 2011

Rising Popularity of the R Programming Language

According to a recent analysis of the search hit popularity of the top 100 programming languages, the R Statistical Computing language, has surpassed both MATLAB and SAS.

I first read about this from the Revolutions blog, a blog dedicated to posting news and content about R, and was happy to see from the survey report charts that the free R software has such relatively high popularity compared to similar languages.  It is worth noting here that the popularity difference is slight due to the fact that this survey counts many languages that are more popular than either R, MATLAB, or SAS. R (#25) had a popularity of 0.561%, MATLAB (#29) 0.483%, and SAS (#30) 0.474%.  Meanwhile Python (#4) has a popularity of about 7%, C (#2) about 15% and Java at #1 with about 18.5%.  The Revolutions blog also makes the important point that the methods used to compute these stats may be a bit controversial, but the stats still serve a purpose.

I first learned R from taking a graduate level statistics course at UMBC, Environmental Statistics 614, and have developed my skills with the programming language to help with data analysis and preparing graphs and figures for papers.  I used R to perform the data analysis and generate the non-map figures for our first paper on Ecosynth and will continue to do so for future publications.

I have only used MATLAB to execute a camera calibration program for my Computational Photography class last semester and I learned a bit of SAS programming for my Multivariate Statistics course last year.  I think both have their uses, but I am really fond of the relatively light-weight size and 'cost' of R.  I am also interested in adding in the scientific and numerical programming functions of Python, SciPy and NumPy.  The SAGE project utilizes SciPy and NumPy to establish a robust free and open-source alternative to for-pay analytical tools like MATLAB, and is also increasing in popularity.  

Free open-source revolution!  This makes me want to put up a post about open-source GIS software...