Leaving for the station to do some final experimental flights!
We do some tests with the quadcopter. There was not enough time (and daylight) besides the SUMO flights to try new stuff.
On our way home to UNIS we stop at the beach and make a final flight with four profiles over sea/land. There is a low hanging cloud. The humidity sensor is saturated during the entire flight. The PT1000 temperature sensor shows an erratic and significantly lower air temperature of -12°C instead of the -4°C the humidity sensor measures in the lower 150m altitude. We have a close look at the flight performance but there is nothing strange to see.
After landing we notice that the propellers leading edge and the wing tip is covered with clear ice.
There was a lot of wind last night. The snow in the surrounding mountains is blown away. There were heavy winds up to 16m/s in 100m altitude. The wind was lower at higher altitudes, only 10m/s in 300m. Nevertheless we stopped flying as no good scientific results were to be expected.
It is the last outdoor day. The groups go into the valleys to collect the weather stations.
Vimeo: Scientific unmanned aircraft over Svalbard
This is a video from spring 2014. It was three weeks later into the year and the sun was up higher. The SUMO flies figures-of-eight automatically at about 100m above the station through Adventdalen. Take-off and landing is manual.
Adventdalen is the main valley, the northern lights station is located in the center and the airport at the end towards Isfjorden. Longyearbyen is located in a side valley (map).
The airport is closed on Saturday and we can go earlier. The first objective is to fly multiple profiles in the narrow Endalen. There are only 100m distance between the flight path and the valley at some points. We head to it with the rumbling belt wagon.
SUMO flies into the valley passing several waypoints and then does profiles on its way back from behind. The plane disappears behind laterally hillocks from time to time while flying low. Very unusual. Normally you would not fly a model airplane visually into terrain. It all works smoothly.
We spend the rest of the evening at Adventalens beach for sea/land profiles. There is a weather change so it will be very interesting flights. There were westerly winds from the sea the last days. Now it switches to colder easterly winds from the land. The air masses interact at the water border, slide over each other creating a sharp boundary, mixing slowly.
In the evening we use the belt wagon to drive to the brink of the transition between ice and water in Adventdalen to measure profiles between sea and land. All four tracks of that vehicle are driven. The steering happens through the hydraulic change of the angle between the front and rear cabin. It is uncomfortably loud inside during the ride, worse in the front as the engine is not really damped.
However, the cabin has the distinct advantage of an easy installation of the 5-hole probe and the fast temperature sensor during the flight preparation. Reading the logger and reprogramming after flight is also a lot easier then on snow scooters.
In general there is little precipitation on Svalbard, it is more of an Arctic desert. Today there are thick snowflakes. We have not yet flown under such conditions. We fear that the fine 12µm platinum wire of the rapid temperature sensor might brake, but we try it anyway.
The wire actually breaks during the third profile just before the descent from 500m. It seems that there was no direct influence from the aircraft. The engine was constantly running at half throttle and there were no strong actuator movements.
The downward facing infrared radiation sensor measures a significantly lower temperature in high altitudes than the soil temperature measured at low altitude. It could be that the raw flakes are colder during the fall as they come from higher air layers.
This time the focus of the measurements is on the heat exchange between the air, the land and the sea water. One group rides their sensor-equipped snow scooters through the valleys, one group goes out on the fjord with a small ship and gathers wind data, air and water temperatures, one operates the balloon at the station and another one flies with the SUMO. Every now and then data from the loggers of the various stations are read out.
We received a permission to fly further out and higher up this time. Vertical flights are a lot more interesting than horizontal ones. We do profiles from 50m-500m in 1km distance in Adventdalen between the station and the shore line.
Checking all SUMOs in the morning, then leave for the cold. We inflate the balloon at the old Aurora station. SODARs were installed next to the station. They measure the air turbulence by means of acoustic signals. Funny beeps with changing frequencies. Sounds like a very cheap bird imitation in the totally silent, almost windless valley.
Gusty winds come up with 10m/s just when the balloon is ready to rise. The balloon has to be brought down and stored in the container.
Meanwhile, the copter was sitting on the ground running with temperature / humidity / pressure sensors. The temperature is quickly floating between -13°C and -9°C. It rises to a steady -8°C when the wind gets stronger. Seems the cold air that slowly flowed from the slopes was displaced by warmer sea air from the fjord.
We will fly the (fixed wing aircraft) SUMO again. In addition we want to do tests with a Paparazzi-driven copter for the first time. We finished the hardware over the last weeks but there is some software for the meteorology sensors missing. I stay in the office at UNIS to finish that.
The student groups set up measurement equipment at various valleys around Longyearbyen. A belt wagon has to be pulled out by a bigger one. It was stuck in a small sea of slush ice that was hidden below snow.
Leaving Oslo is a little bumpy. The cellphone check-in does not work, the ticket computer does not like my identity card, the lady at the desk takes the card and verifies it somewhere behind. “All good, get your seat at the gate.” While I trudge through the airport, I see myself wait at he gate and not get a seat, the next flight would be tomorrow.
But everything is good. I get a seat in non-economy right away. There is the immigration run around the the aircraft in Tromsø and then Svalbard!
There is just about enough daylight to take a photo when we land at 14:00. When the luggage arrives the light would not have been enough. But at this time of the year the light increases dramatically each day.
Going back to Svalbard for UAV flights! After takeoff the sun rose over the horizon, was fully visible for a few minutes and perished into the clouds.
There is an over night stopover in Oslo again. Do not take the express train to the city center, even though the vending machine is trying to push you to. The normal NSB train is only half the price and runs just 4 minutes longer.
Enjoyed the Fram museum as a preparation for the trip. The research vessel was built for the Arctic/Antarctic 120 years ago. It was used by Amundsen to reach the South Pole. It seems not very “technical” from the inside by todays standards.
Added some code that reduces the total binary size and thereby allows you to run the Paparazzi autopilot software on standard quadcopter hardware like the Naze32. It needs some documentation and example files that will be added to the Wiki once the weather gets better to fly. It even runs on the tiny CJMCU platform. Unfortunately you have to replace the original 64kByte flash processor (F103C8T6) with a 128kByte type (F103CBT6).