Ubuntu on Hawkboard and Statistics on SAR

The mind is a massively parallel device - at least at the neuron level. I am always doing multiple things simulataneously. Multiple in the sense of intellectual heritage, yet unified in a sense that I am doing something that interests me and I might as well call it an unique discipline - how to see at all parts of the spectrum or how to get to mars. In essence it is domain unified.

Last few days I have been looking at arm twisting the low-power DSP on the hawkboard into doing some image processing. Porting OpenCV to the DSP on beagleboard seems to be proceesing pretty well. I will have to build that and give it a try. For now I am satisfied setting up a dsplink enabled kernel and Ubuntu image from an SD card. The root image does not contain UVC drivers so I can't use my USB cameras, but at least the Hawkboard is operational. Time to switch attention to the BeagleBoard and give the dsp enabled opencv a whirl.

On the otherside I did some eigen decompositions of dual-polarimetric TerraSAR-X and PALSAR and noted how wildly different grasslands appear at L-band vs X-band. While L-band sees predominantly surface scattering, X-band is carried away by volume scattering. The X-band VV channel seems statistically most responsive to the pasture biomass, but the confidence of my statistics with only 33 sample points is rather rudimentary. The pastures are fairly dry (10% moisture) as opposed to wheat I have worked with in the past (50-60% moisture), this significantly reduces the radar cross-section and the net backscattering needs to be explained in terms of additional parameters. In this case there is significant influence from surface roughness and moisture content, backscattering increasing with increasing roughness and decreasing with increasing moisture content. Where the entropy is low I will investigate the negative-alpha filter for retrieving soil moisture.

In dual-polarimetry the alpha angle contains ambiguity and can often be misrepresented as multiple scattering. This ambiguity cannot be resolved without considering the  actual targets of interest.

HackerSpace Adelaide - Flying Crates and Hawkboard Screen

Today at hackerspace we got carried away a bit with helicopters. There were attempts to even get a crate to fly. Instead of flying the crate nudged along the ground. By the end of the night the radio control had come out of the said helicopter and the motor controlling PWM was being viewed on an Arduino oscilloscope.

We also managed to get the Hawkboard up on a VGA monitor and all the way to showing the Ubuntu login screen. We are planning to pool and buy a few more HawkBoards, everybody is dreaming up stuff to do with them. I have mentioned RADAR on a small UAV before, now it seems to be a real possibility with the ISEE RADAR. Time will come when there will be drones flying around giving out speeding tickets.

Dog and Birds - Hawkboards and BeagleBoard

The HawkBoard costs about 1/2 the price of a BeagleBoard, only on special though. So I killed 2 birds with 1 stone and got 2 of them from Special Computing and 1 BeagleBoard from DigiKey.

They both used $30 delivery mechanisms - UPS Express Saver and USPS International Express. The postal service beat the courier by a day since the courier does not deliver to the remote areas every day.

Anyway everything is finally here and the hawkboard is the easiest to get started with since it has an on-board serial connector - no soldering needed. I got Ubuntu installed with this guide and the following modification:

1) Load the kernel using - bootp 0xc0700000 [ip]:uImage
2) Slight changes in bootline – added mem=128M
3) bootm from 0xc0700000
4) The global chmod 777 prevents you from using sudo. You need to chmod 4755 on /usr/bin/sudo and 440 on /etc/sudoers.
 
Otherwise ubuntu jaunty just works and I even have my favourite Python to play with on the tiny board. Nothing of this form factor has afforded me this pleasure in the past. Next step is to install some components of ROS on it and start building the LocalHawk - localized UAV version of the GlobalHawk.