Question 1 (40 marks) Given a LiDAR system with a laser wavelength of 900 nm, attached to a drone flying at an altitude that ensures a beam footprint of approximately 0.2 square meters on the ground. Analyse the detectability of objects with different reflectivity, assuming a minimum reflectivity threshold of 5% for detectability by this system. See the following Activity tasks. Activity: 1. Calculate the minimum detectable object size for an object with a reflectivity of 5%, using the illuminated area of 0.2 square meters (15 marks). 2. Determine if the LiDAR system can detect the following objects based on their reflectivity and the calculated minimum detectable object size (5 marks each): * A white masonry wall with a reflectivity of 85% and dimensions of 1 meter x 1 meter. e A pile of rough wood pallets with a reflectivity of 25% and dimensions of 0.8 meters x 0.8 meters. Snow-covered ground with a reflectivity range of 80-90% and dimensions of 2 meters x 2 meters. * A lava rock surface with a reflectivity of 8% and dimensions of 0.1 meters x 0.1 meters. A black neoprene (synthetic rubber) surface with a reflectivity of 5% and dimensions of 0.1 meters x 0.1 meters. Question 2 (140 marks) Task 1 (90 marks) You are tasked with exploring three scenarios where Airborne LiDAR technology can be effectively employed: Each scenario (30 marks each) introduces unique challenges and opportunities. You are asked to weigh the pros and cons of LiDAR, choose between full waveform or discrete LiDAR data, and deliberate on aspects such as georeferencing, calibration, and other important factors relevant to each scenario. Scenario 1: Forestry Management Imagine you have been asked to join a forestry management team responsible for evaluating tree density, heights, and canopy health across an extensive forest area. Scenario 2: Disaster Management Envision that you have been tasked with being part of a disaster management team addressing a natural disaster, such as a flood or landslide. A swift terrain assessment and the identification of affected areas are crucial. Scenario 3: Mining Operations You are asked to contribute to a mining company's efforts to optimize operations and ensure safety within a large open-pit mine. For each scenario, you are tasked with creating a comprehensive strategy for the application of Airborne LiDAR technology. Address the specific challenges and advantages associated with each use case. Consider the following aspects: + The type of LIDAR data + Georeferencing Calibration Any other critical factors relevant to the scenario. Task 2 (50 marks): Now that you understand the three LiDAR applications, it's time to dive deeper into one of them based on your interests. Follow the steps below to complete the task: Step 1: Choose an Application Select either Forestry Management, Disaster Management, or Mining Operations based on your preference. Step 2: Access LiDAR Data: Visit the ELVIS platform, where you can find LiDAR datasets. Identify a location related to your chosen application. ELVIS provides access to a wide range of LIiDAR datasets. Step 3: Download LAZ Data Once you have identified a suitable location, download the relevant LAZ file to your local computer. Step 4: QGIS and DTM Creation: Open QGIS software and use it to create a 3D model from the LAZ file you downloaded. Follow the steps outlined in the Module 2-Topic 1-Practice tutorial on working with LAZ files in QGIS. Provide screenshots of the final 3D model. Question 3 (70 marks) Your task is to perform calculations for LIDAR flight planning based on the provided information. Using the given input parameters, you are required to calculate various essential parameters for efficient LIDAR data collection. Given Parameters: + Platform speed (v): 50 m/s (Assuming unknown aircraft speed). Scanning rate (fsc): 800 Hz Swath Width (0): 45 degrees Number of points per scan line (N): Laser pulse rate (f pulse) = 400,000 pulses per second (to be determined by the student). Flying altitude (H): 200 meters AGL (Above Ground Level) Terrain slope (i): -5 degrees Overlap factor (e): 120 meters Tasks (10 marks each): 1. 2. N oo A Calculate the point density in the flight direction (AX along). Approximate the point density across the flight direction (AX across). . Calculate the point density across the flight direction (AX across) considering the flying altitude and terrain slope. . Determine the minimum point density (dmin). . Calculate the maximum slant range (Rmax). . Determine the swath width (SW). . Set the overlapping factor (OV) and determine the recommended overlap percentage for the survey