At-field- Pre-Flight Checklist
1.3. Preflight Checklist – At field before arming 1.3.1 Camera settings (Based on Canon PowerShot S100/S95/S110 Point & Shoot cameras) General recommendations for aerial imagery:
Keep the camera focal length fixed throughput the mission. Shoot in RAW since the RAW format retains maximum scene details and provides greater flexibility during post-processing. Use faster shutter speeds to avoid blur due to vehicle speed and vibration. Use gimbal to get maximum nadir shots of the scene and to avoid image blurring. Choose one of the following camera settings: Manual (M) mode: Shutter speed: fastest or close to fastest (for S100 canon, 1/1600 or 1/2000 would work, depending upon the UAV speed and weather conditions) ISO: ~80-250 (adjust based on ambient light). Hint: Higher ISO, brighter image but higher noise. Aperture (f-number): 4.0-5.6. Note: Small f-number means wider apertures and shallow depth of field. In our experience, F-number of 4-5.6 is a sweet spot. It is recommended that you play around with the manual settings to setup your camera to suit your specific requirements. Ev (exposure): -1/3 or -2/3. Again, adjust based on ambient light conditions. Additional note: Use the vertical bar with moving pointer to adjust the camera settings to get proper exposure (not too bright and dark). The pointer should point at or below the mid-mark. Shutter Priority (Tv) mode: In Tv mode, only shutter speed needs to be adjusted, ISO and F-number are automatically adjusted by camera based on scene conditions. Shutter speed: fastest or close to fastest (for S100 canon, 1/1250, 1/1600, or 1/2000 would work, depending upon the light conditions). Quick tip: faster shutters less light hitting the sensor. Optional: Ev (exposure): 0, -1/3 or -2/3 (again adjust based on ambient light conditions) Set the Manual Focus (MF) setting to infinity for above 5 meter altitude flights. Image recording format: Camera raw (CR2) Under MENU option, make sure: GPS ON MF-point ZOOM OFF Safety MF OFF Wind Filter OFF → General recommendations for aerial imagery: Keep the camera focal length fixed throughput the mission. Shoot in RAW since the RAW format retains maximum scene details and provides greater flexibility during post-processing. Use faster shutter speeds to avoid blur due to vehicle speed and vibration. Use gimbal to get maximum nadir shots of the scene and to avoid image blurring.
1.3.2 UAV In-field Pre-flight Place the UAV on a flat surface, plug-in the battery and close the lid. Note: Avoid any disturbance to the UAV during initial few seconds as the UAV performs automatic sensor-calibrations. Lock the SD card and insert it in camera. Switch-on the camera by pressing the preview button. Half-press the shutter to let the lens out. Set the camera parameters by following the instructions in section 1.3.1. Attach the camera to the gimbal mount and plug-in the wire. Load and run CHDK script by half-pressing the camera shutter button. Open mission planner on field laptop and connect mission planner to UAV Autopilot using telemetry radio link. Use a correct COM PORT Number and 57600 Baud rate from the drop down menu on top right corner of mission planner software. Then hit connect. Check flight parameters (see parameter section below for detailed parameter list) Load proper mission waypoint file and write the waypoints into the Autopilot through radio link. Note: You can read back the WP from UAV to double check the correct WayPoints are written to the UAV. Make sure the GPS signal is good (3D fix: number of satellites > 7 and hdop < 2) and there is no error message flashing on the mission planner main window. Check if the camera trigger is working properly by walking the UAV. Note: Make sure the UAV safety light is flashing to avoid accidental arming. Check battery voltage. Turn the radio controller (RC) transmitter on. Check to make sure the RC switch positions are set to: Stabilized Mode [ON], RTL [OFF], Throttle [All the way Down]. Depending upon how the other RC switches are mapped, make sure the switches are set to a mode that is safe for take-off. Check the trims are zero (offsets to stick positions that can be set with small slide switches). Make sure no one is close to UAV and survey area.