DOI: 10.5281/zenodo.7736335
title: Multi-Altitude Aerial Vehicles Dataset

description: <strong>Custom Multi-Altitude Aerial Vehicles Dataset:</strong> Created for publishing results for ICUAS 2023 paper "<em>How High can you Detect? Improved accuracy and efficiency at varying altitudes for Aerial Vehicle Detection</em>", following the abstract of the paper. <strong>Abstract</strong>—Object detection in aerial images is a challenging task mainly because of two factors, the objects of interest being really small, e.g. people or vehicles, making them indistinguishable from the background; and the features of objects being quite different at various altitudes. Especially, when utilizing Unmanned Aerial Vehicles (UAVs) to capture footage, the need for increased altitude to capture a larger field of view is quite high. In this paper, we investigate how to find the best solution for detecting vehicles in various altitudes, while utilizing a single CNN model. The conditions for choosing the best solution are the following; higher accuracy for most of the altitudes and real-time processing ( &gt; 20 Frames per second (FPS) ) on an Nvidia Jetson Xavier NX embedded device. We collected footage of moving vehicles from altitudes of 50-500 meters with a 50-meter interval, including a roundabout and rooftop objects as noise for high altitude challenges. Then, a YoloV7 model was trained on each dataset of each altitude along with a dataset including all the images from all the altitudes. Finally, by conducting several training and evaluation experiments and image resizes we have chosen the best method of training objects on multiple altitudes to be the mixup dataset with all the altitudes, trained on a higher image size resolution, and then performing the detection using a smaller image resize to reduce the inference performance. The main results The creation of a custom dataset was necessary for altitude evaluation as no other datasets were available. To fulfill the requirements, the footage was captured using a small UAV hovering above a roundabout near the University of Cyprus campus, where several structures and buildings with solar panels and water tanks were visible at varying altitudes. The data were captured during a sunny day, ensuring bright and shadowless images. Images were extracted from the footage, and all data were annotated with a single class labeled as 'Car'. The dataset covered altitudes ranging from 50 to 500 meters with a 50-meter step, and all images were kept at their original high resolution of 3840x2160, presenting challenges for object detection. The data were split into 3 sets for training, validation, and testing, with the number of vehicles increasing as altitude increased, which was expected due to the larger field of view of the camera. Each folder consists of an aerial vehicle dataset captured at the corresponding altitude. For each altitude, the dataset annotations are generated in YOLO, COCO, and VOC formats. The dataset consists of the following images and detection objects: <strong>Data</strong> <strong>Subset</strong> <strong>Images</strong> <strong>Cars</strong> 50m Train 130 269 50m Test 32 66 50m Valid 33 73 100m Train 246 937 100m Test 61 226 100m Valid 62 250 150m Train 244 1691 150m Test 61 453 150m Valid 61 426 200m Train 246 1753 200m Test 61 445 200m Valid 62 424 250m Train 245 3326 250m Test 61 821 250m Valid 61 823 300m Train 246 6250 300m Test 61 1553 300m Valid 62 1585 350m Train 246 10741 350m Test 61 2591 350m Valid 62 2687 400m Train 245 20072 400m Test 61 4974 400m Valid 61 4924 450m Train 246 31794 450m Test 61 7887 450m Valid 61 7880 500m Train 270 49782 500m Test 67 12426 500m Valid 68 12541 mix_alt Train 2364 126615 mix_alt Test 587 31442 mix_alt Valid 593 31613 It is advised to further enhance the dataset so that random augmentations are probabilistically applied to each image prior to adding it to the batch for training. Specifically, there are a number of possible transformations such as geometric (rotations, translations, horizontal axis mirroring, cropping, and zooming), as well as image manipulations (illumination changes, color shifting, blurring, sharpening, and shadowing).