Objectives

Well, it is time to lay out some objectives again as we need to keep our focus and continue moving in a productive direction. In this post I'll provide a brief update on the state of the lab and outline some short and longer-term objectives.

The Catfish is flying well these days, and all testing has pointed to good, highly reliable flight. Marcus constructed a new pan/tilt gimbal for the nose of the plane to hold the camera in a position that will allow us to image the knob of Pilot Mountain. It was test-flown on Saturday with excellent results. Everything else with the Catfish is squared away, except for camera triggering. We lost that function when adding the gimbal, as we had to move the servo connections around. The good news is that it should be trivial to regain this functionality, it will just take a few minutes of doing. The use of the airspeed sensor and Total Energy Conservation System (TECS) tuning is on hold until we have flown Pilot, as we want to fly at the peak of fall colors and can't afford to break anything now.

DeaconEye is still grounded, as I fried a power distribution board on Friday and we are working on putting together an alternative solution. Everything else on it should be ready to fly, and once we get the power situation worked out it will be time to re-tune the aircraft with the new ESCs.

As shown in the posts below, we have imagery from Duke Forest and analysis of this is pressing. From this imagery and the imagery collected with DeaconEye, we want to start producing real data. This is what much of the "off-season" will center around.

Finally, the deadline for the National Geographic grant is almost here (October 22nd). Our pre-proposal was approved and now we need to put on the polish and get it submitted. Simply put, we can't let this one get away.

So with that recap, here are the objectives, in a rough order of importance:

Near-term (next 3 weeks):

1. Develop and implement a power distribution solution for DeaconEye
2. Re-tune DeaconEye
3. Finish National Geographic grant
4. Fly Pilot Knob

Long-term (next 3 months):

1. Delineate tree crowns in Duke Forest imagery and correlate data to known tree data
2. Apply canopy illumination model to 3D canopy model
3. Implement Catfish airspeed sensor and TECS
4. Fly somewhere exotic (Peru?)
5. Procure fluorescence sensor
6. Procure 20 mm prime lens for Sony NEX-5R
7. Procure low-light/night vision/thermal recording and FPV system

Pacific Winds are Favorable

One of the missions we want to fly is out over areas in the middle of the eastern Pacific.  One of the problems with flights in oceanic areas is that the winds can be strong, and it is hard to get information for a lot of the earth on the scales we need it.

I was poking around the National Data Buoy Center for windspeeds this morning.  There are buoys tethered out in the ocean that measure climate and oceanic variables for studying ENSO.



Here are the daily mean wind speeds from April-today measured at 4m for buoys at:

8N, 95W   4.3 m/s  9.6 mi/hr  <--- west of Cocos Island
2S, 95W   5.0 m/s  11.2 mi hr <-- west of S. Galapagos
[Continued below the fold]

DeaconEye Overhaul

DeaconEye mid-overhaul, shown with the new ESCs, new power distribution board, and a motor ready for new bearings.

Well, what started as a handful of upgrades and repairs has turned into an almost complete overhaul of Deaconeye. Here is an outline of what has been done and what is in progress (Continued below the fold):

Duke Forest

Well, it has been a little while since the last time I posted and there is quite a bit to talk about since then. First of all, Marcus and I went to Duke Forest on Saturday and flew all of 4 of the plots that we wanted to fly. In short, it was a pretty incredible day of flying with ~70 km of linear flight in ~120 minutes. We imaged 2 plots per flight and used the "multilooked" method Miles discussed earlier on the blog. Here is a look at our first flight:

You can distinctly see where we took off in the open field as well as the two plots we imaged in this flight. The colors indicate flight modes, with orange being manual and the green being auto. Below is the profile of our second flight:

The images from these flights are looking pretty good, although we have a clear need for a higher-quality camera. Below you can see the preliminary mosaic of our second flight:

This is only a subset of the mosaic which excludes peripheral areas which are not in the area of interest and are not imaged well. You can see a few errors along the road at the top; Photoscan is known to produce errors along straight lines.

Finally, here is what I am affectionately calling the Asnerian View (an oblique view of the 3D model):

So, from this we have learned quite a bit. We have learned that the camera we are using in the Catfish has a few idiosyncrasies which we are learning to overcome along with a diminutive sensor which makes collecting good imagery on anything other that a bright, sunny day quite difficult (the sky when we made these flights was overcast). All in all, though, we have proven that the Catfish is a really great, reliable system for imaging large areas in a short amount of time. Our next project for it will be to go to Pilot Mountain and image the knob.

Upgrade Time

We have taken the downtime resulting from our close encounter with a tree with DeaconEye and the wait for an airspeed sensor for the Catfish to work on some upgrades for both.

The Grind

Today we're hard at work on the daily grind. Hand-balancing propellers, installing a new gimbal motor on DeaconEye, and repairing a faulty connection in the Catfish. The work in the SUAS lab isn't always glamorous, but it always brings us closer to our goal of safe, reliable flight collecting usable imagery that helps us answer the research questions. Who knows what ecological breakthrough will come from the balanced prop?

Good news/bad news

Well, I'll start with the good news. Today we took Catfish out to the RAMS field to dial in the APM settings and had some outstanding flights. We went through the APM recommended tuning procedure, tuning roll, pitch, yaw, and autopilot navigation. The results were so good compared to the out-of-the-box settings that Marcus even said he might like flying in fly-by-wire mode better than manual. We got response in FBW to be crisp and manageable, something we have not seen before. We got flight in auto mode to be extremely accurate in most cases, making tight turns to stay on track and hugging the planned flight lines. We also