Thermal Imagery Flight--03/07/2016

Introduction

The weather was unseasonably warm for the 7th of March, so our professor called an audible an we headed out into the field to fly a couple missions. The objective of the mission were to capture thermal imagery of the gardens, and ponds at South Middle School in Eau Claire, WI.

Methods

After meeting at the school we prepared the Matrix UAS platform which had already been affixed with a thermal sensor. After removing the Matrix from the case, the motor/rotor frame arms were extended and the battery was balanced as it was attached.

(Fig. 1) Teaching Assistant Mr. Bomber unfolding and securing the motor/rotor arms.

Our professor, Dr. Hupy prepared the base station and flight plan with in Mission Planner for the flight over the community gardens.  For more information about Mission Planner check out my previous blog post.

(Fig. 2) Dr. Hupy preparing the base station and creating the flight path in Mission Planner.

Before any flight can take place we have to perform a pre-flight check.  The pre-flight check includes and ever expanding list of checks for all of the components involved in operating the UAS platform. Many of the checks on the list are derived from issues previously encountered during flights. Checking the electrical connections, battery charge,  blades, and motors are just a few of the items which are on the list of checks.  Identifying issues and curing them previous to flying is crucial for not only the safety of those involved with the flight but individuals outside the flight path which could be affected with a flight issue which could send the platform in an undesired direction.

The platform we flew was custom built quad-copter with a thermal sensor attached (Fig.3).

(Fig. 3) Matrix platform with thermal sensor attached.

While the flight Mission Planner creates has a take off and landings built in, manual take offs and landings are safer with an experienced pilot (Fig. 4). The manual landing and take off does not take into consideration of the surface of the ground and cannot see object which may cause it to crash. Additionally, when launching the platform manually you can engage loiter mode which is a good test to make sure all of the systems are functioning properly.  Loiter mode takes over the control of the platform hovers at the altitude which the mode was engaged.

(Fig. 4) Mr. Bomber manually launching the platform prior to engaging the flight plan from Mission Planner.

Results

(Fig 5) Displaying the results from the thermal sensor and mosaic for the community gardens.

(Fig. 6) Displaying the results from the thermal sensor and mosaic of the pond area.

Discussion

The thermal sensor we utilized in this flight is new to our arsenal of sensors.  To the best of our understanding the values give are relative to the entire image.  This can be seen when comparing the two resulting images above.  Notice the road area in Fig. 5 has a displayed value less than the values of the same area in Fig. 6.  The same can be noticed for all of the values in the northwest portion of the displayed maps where the images overlap areas.

The lack of consistency of values between images makes the sensor relatively useless for comparison between images or attempting to figure out the true surface value.  Flying the area you wish to analyze should be flown in one flight with this sensor to make proper comparisons of surface temperatures.

The above issue could be simply our lack of understanding of the sensor and will require more investigation on our part to fully utilize all the functionality of the sensor.  Our class has many flights planned in the future to continue investigating the uses of the thermal sensor.