After nine separate drone flights (not including the one that led to the loss of Sky Hunter), we successfully surveyed the lower portion of Tasman Glacier! The blue dots in the image below show the locations of all of our camera shots -- a total of 2,735 in-flight photos. To give you a sense of scale, the survey covered 6km lengthwise, and, on average, just over 2km in width.
Our final launch and landing location was further downglacier than we had gone before, and our landing sites were becoming increasingly more subpar. Luckily, New Zealand bush is both plentiful and generally soft, so we identified a hill slope that could serve as a padded landing zone, as can be seen in the image to the left. We're naming this drone landing technique the Anderson technique, after Brian landed the RV Jet in the hill slope five times with no damage to the plane.
Before our final day of flying, we returned to our flight logs to figure out what exactly had gone wrong with the Sky Hunter. While we first suspected that a strong wind had brought us down, it appears that the real culprit was our Sunnysky motor. Mission Planner showed that we were pulling zero or close to zero amps at the end of the failed Sky Hunter mission, and while the autopilot was asking for throttle, the plane was unable to deliver due to motor failure. After doing a second sweep of the moraine walls, we were also able to locate the Sky Hunter from above, where it is sitting exactly where we expected based on its communications with our ground station. Unfortunately, this still means that it would be too dangerous to retrieve, so we will leave New Zealand without it.
Despite this loss, we're pretty happy with how the full mission turned out -- and are looking forward to processing the images (using Agisoft PhotoScan Pro) to see how our DEM turned out. The glaciologists we were working with plan on returning next year to make an updated DEM to see how the glacier is changing. We're looking forward to staying in touch with them to hear about these results, as well as other uses of drones in New Zealand!
On that note, the Agribotix team remains in New Zealand for another week. We're done with our Tasman Glacier flying, and are moving to data processing, but would be happy to do more flying with our remaining drone. If there's anyone on the South Island following our progress who has an interesting project that could use some aerial photographs, contact us at email@example.com !