The Dimensions of the 3p and AIS, measured in millimeters:
3p AIS Schematic
The 3p accepts power sources from 9-36V; we recommend a 3-6 cell battery. A rough estimate to calculate the sensor's "on-time" is to calculate a battery's total capacity and then divide by the sensor's power draw of 11W. Peak draw is 3A upon sensor startup.
For example: 14.8V x 1300mAh = 19240 mW or about 19.2WH 19.2WH / 11W = 1.75 hours of 3p "on-time"
Image overlap (along-track) is a function of the data collection rate of the sensor, the size of the image on the ground at the given flight altitude, and the flight speed of the aircraft. The sensor is collecting images approximately once per second, so the distance the aircraft travels in one second should not exceed 80% of the image’s along-track dimension.
Many flight planning software packages will automatically space your flight legs when given the parameters of the imaging system and the required sidelap. The sidelap for a 3p sensor should be 20% to 30%.
See the tables for image size, recommended maximum speeds at various altitudes, and optical parameters of the 3p system oriented nadir.
If flying a multirotor, you must angle the sensor mount to compensate for aircraft pitch at the chosen speed.
3p field of view from various altitudes
|Image Width (m)||12.8||15.4||18.0||23.0||30.7||46.0||61.4|
|Image Height (m)||10.2||12.3||14.3||18.4||24.6||36.9||49.2|
3p Max flight speeds at various altitudes
|Max Ground Speed (m/s)||6||7||8||11||12||12||12|
Depending on your aircraft setup (multiple batteries, multiple sensor payloads, etc...) and the wind conditions, flight speeds above 12 m/s may orient your sensor significantly off-nadir. The standard 8 degree mount is not sufficient to keep most multirotor aircraft oriented nadir at flight speeds above 12 m/s. Increase the angle or lower flight speed as needed.
If using flight planning software packages that require imaging system parameters, enter the following:
3p Imaging system properties
|Focal length (m)||Pixel Pitch (m)||Pixels Wide||Pixels High||Focal Plane||Frame Rate (Hz)|
|0.012||0.0000048||1200||944||5.76mm x 4.53mm||1|