Part 2 – UAS Operations
Once the mission is flown and images safely acquired, the next step is to head back to the office for an operational debrief. The main purpose is to verify that the mission proceeded according to plan and that the correct data set was acquired. Equally important are the things didn’t go quite as planned in order to improve the safety and efficiency of the operation in the future.
Assessing Mission Success
There a number of factors determining mission success;
- Image quality
Safety is of utmost importance because it directly affects the ability to carryout subsequent missions. This is why it is imperative that all UAS operations are conducted with safety first and foremost in mind. Safety itself can be evaluated based on a number of criteria such as equipment, personnel, property and the public. It is worthwhile to discuss any areas where safety may have been compromised and where it can be improved.
The main goal of a photogrammetric image acquisition mission is to safely and efficiently collect the correct number of high quality images for subsequent processing. Thus, even though a mission may have been deemed successful from a safety standpoint, it could be a failure if the right number of quality images are not captured. Any areas or procedures that may have compromised capture of quality images, should be evaluated.
For example, the effect of manual versus automatic photo capture settings in DJI GO app may result in images that are too dark, over exposed or blurry. Also using JPG versus RAW image format can affect post-processing steps. Images with insufficient overlap, taken at an altitude that is too high to see objects of interest or where the ground isn’t clearly visible due to trees, shadows or other obstructions may negatively affect the outcome of a mapping project.
Communication between the PIC and team should not be underestimated. If the PIC does not clearly communicate what they are presently doing and their next intentions, the safety spotter and possible ground access control crew may be left wondering what stage the operation is at. Simple, frequent updates as to what is happening with the UAS will help the ground crew understand what they should be doing at any given moment.
This becomes even more important when the ground access control crew is managing access to the flight area. It is helpful to brief the crew when to expect communication and what is expected of them at each stage of the operation.
Efficiency of the operation cannot take priority over safety, image quality or communication and yet it can definitely affect mission success. If the mission cannot be completed in the allotted time or at a certain time during the day, it can result in mission failure. For example, if a planned daytime flight cannot be organized with sufficient time before sunset, it will have to be aborted. Rapidly changing or deteriorating weather conditions can also cause inefficiently planned or executed missions to be grounded. Sometimes equipment issues will require re-flights (e.g. blurry images due to improperly focusing camera) or a software app becomes unresponsive.
One of the main benefits of post-operational debriefs is to improve safety, ensure quality image, improve communications and raise the level of efficiency of future UAS operations.
Once the UAS and crew are back in the lab or office, the UAS and components need to be removed from the case and cleaned of any debris (dust or grass). Batteries need to be connected to chargers and images downloaded to a workstation from the memory card. Any equipment issues need to be documented in the UAV Logbook app under the correct mission.
Once the data have been downloaded and verified, the memory card should be formatted in preparation for the next mission and inserted back into the UAS slot. When the flight batteries, Controller and iPad have been fully recharged, all components need to be securely placed back in the case and the case returned to the safe storage area.