### Formula for determining resolution (cm/pix)?

Im trying to determine the resolution of my camera for mapping. Its 12.1mp, flight altitude is 320 feet.

I have this chart for a 10mp camera, but is there a formula someone can share?

10mp.jpg

#### Replies

• i have tested if we use photogrammetry standard formula  GSD = flight height (m) / Focal lenght (mm) x pixel size maybe we cannot find GSD as report software like agisoft photoscan report software. but if we use this formula GSD = (sensor height (mm) x flight height (m) x 100) / (focal lenght (mm) x image height (pixel)) we can get result as like software report. for example i use DJI phantom 3 pro camera that focal lenght = 3.61, sensor height 4.62, image height = 3000 pixel and flight heigt 173 m, from mission planner i can get result GSD 7.38 cm, from calculation using the formula GSD = (4.62 x 173 x 100)/(3.61 x 3000) = 7.38006

IMHO, maybe useful

• Hello,

I am a student at UW-Green Bay and have worked with one of my physics professor to come up with an equation for the situation which you are asking. The equation is below in the image and is based on the way you calculate resolution for telescopes. You will need to use this equation twice to calculate the distance covered in both the x and y direction.

I hope this helps!

• brother where can i find focal plane?

Pierre Stoermer said:

Hi Matt:

Try this: GSD (ground sample distance or resolution/pixel) = Pixel size X AGL / Focal length where:

Pixel size = focal plane width or height (in mm) / focal plane # of pixels in either width or height,

AGL = elevation above ground in meters,

Focal length in mm.

Additionally the frame size on the ground is GSD x focal plane # of pixels in either width or height.

Pierre

• This app has a UAV Photo Coverage Calculator:

http://playboard.me/android/apps/com.xdrones.dronestoolsupdate1?lan...

• I realize this is a fairly old thread, but just today I was working on this problem and after I solved it (I think), I found this discussion. Others have already provided a number of good answers and resources but I thought I'd add my own. The attached Excel spreadsheet is not as comprehensive as the one provided by Drones Imaging but has a few different calculations you might find useful. Please let me know if you see any errors or have suggestions.

AerialSurveyPlanner.xlsx

• Hi Matt,

Good luck

• Over a year late, but since this is the first thing that appeared to me on Google, maybe this can help:

http://www.canon.com/bctv/calculator/calculator3.html

By the way, don't know how that graph can help if it doesn't show focal length.

• You might find the Dimensional Field of View Calculator on this web page handy.

http://www.tawbaware.com/maxlyons/calc.htm