How Do You Scale an Aerial Photo?

[Awilson18]

Is it possible to take an aerial photo, then using AutoCAD(or something similar) scale the photo? Example: 1in = 1,000 ft

Any help is appreciated!

 

[Flycaster]

If you KNOW the size/length of something in the image, like a big box container, auto or barn for example, something along those lines, then yes, you can scale to get a "close estimate" of the other objects in the image...
You need a "reference" point/object....

 

[vindibona1]

I would suspect it is possible to scale a photo if you know the geographical distance/measurements of what you have photographed. I would think that Adobe Photoshop would be a good tool for that because you can select the canvas size you're working in which the measurement tools can set to feet, inches, centimeters, millimeters, percent points, pixels or picas (for typographers). Within the document you can drag in guides and even reset "0" in X and Y axes and then scale your photo to the appropriate measurements. Following the scaling you can then change the size of the "canvas" so that the image falls within whatever size paper you wish. I'm sure there are other programs that have similar features, but Photoshop is the one I'm most familiar with.

 

[PhantomFandom]

Is it possible to take an aerial photo, then using AutoCAD(or something similar) scale the photo? Example: 1in = 1,000 ft

The responses above are correct as long as the objects in question are all in planview and there is no fisheye distortion from the lens. Basically you need to be looking at a 2-D representation of the object where everything you need to mention is in the same plane. Then you can indeed use a frame of reference to measure other objects in that same plane.

If you are trying to measure distances on a 3-D photo where the measurements are of objects in different planes then it all falls apart, since you do not have the necessary distances and angles to do the necessary calculations.

 

[Meta4]

Is it possible to take an aerial photo, then using AutoCAD(or something similar) scale the photo? Example: 1in = 1,000 ft

Accurate measurement is not possible with a single photo as 1" of foreground (oblique) or 1" centre (looking straight down) covers a very different distance from other parts of the image.
But it is possible using a composite image called an orthomosaic created from many overlapping images, stitched and corrected with specialised photogrammetry software.

 

[ArcTenTen]

Is it possible to take an aerial photo, then using AutoCAD(or something similar) scale the photo? Example: 1in = 1,000 ft

Any help is appreciated!

Yes, as long as you have something scalable in the photo. For example, you could use a 100’ tape measure to place some markers on the ground or, if you have a parking lot, you could field measure and then use the parking stripes to establish scale.

If there is a simple way to calculate a scale given the telemetry of the photo, I’d love to hear about it.

 

[bcfd29]

overlaying GPS coordinates with a GIS based mapping system like ARCGIS/ARCView would likely also work but because your image is not perfectly flat there will be some "rubber sheeting" and correlation will not be exact. GIS mapping is usually available in the public domain from the governmental entity where your doing the work. Make sure you use the SAME coordinate system as the GIS imagery...

 

[Lets Fly]

Is it possible to take an aerial photo, then using AutoCAD(or something similar) scale the photo? Example: 1in = 1,000 ft

Any help is appreciated!

If looking straight down or forward at any two separated objects, I go to google map and double click on one object and get measure distance.
Then click on the other and get the distance. Our field of view depending on the drone camera is a certain degree, but measuring on google map still tells you
the actual distance and perhaps you can calculate or estimate in your photo the scale from there.

 

[Ledaig]

Fairly straight forward according to this - the part you are looking for is halfway down the page:

Scale Calculation

Only for straight down images though!