Which way to orient camera?

I am developing a spreadsheet, and some python for mission planning: where will the plane fly, where will it turn, what size memory card do I need, etc.

Right now, I’m treating the collected images as being squares the size of the height of the image. The full sensor is a rectangle, and I’m wondering how should I model the camera on the plane?

Should the camera be attached vertically like this?
Screen Shot 2021-02-22 at 11.58.50 AM

Or horizontally like this?
Screen Shot 2021-02-22 at 11.59.09 AM

1 Like

Depends whether you’re more overlap or sidelap constrained.

Most sensors are actually not square, but are close (3:2 being a typical CMOS sensor ratio).

In the first image, you’ll have more overlap than you will sidelap.
Why would you want this?
If your sensor writes out slowly, orienting this way “buys” you slightly more pixels along your flightpath per exposure, which can be helpful in keeping your flight speed up.

In the second image, you’ll have more sidelap than you will overlap.
Why would you want this?
Sidelap costs flight time. You need to fly more transects closer together to get more sidelap, or conversely, fly higher and lower your GSD. Having the camera oriented in this manner gives you more pixels for sidelap along your flightline, which will help you reduce (very slightly) the number of flightlines needed to cover a given area at a given GSD.

In summary:
Overlap is limited mostly by how fast your sensor can capture and write out an image. Cranking the overlap up mostly just costs you storage space and processing time.

Sidelap is a physical property of the sensor and the flight plan. It costs you flight time. This is where, I believe at least, you need to be most consientous of how you plan.

I’d orient the camera properly (wider axis perpendicular to direction of travel), like in your second image.


This is a great summary. Can you add some of this to the flight planning page on docs when you get a chance?


The images are creative commons, and you can use my collage.