Understanding Aerial Photos

Shadows can play an important role in trying to figure out what you are looking at.

Here in this photo, you can see a large commercial broadcast tower for a TV or radio station (probably both).

Note the direction of the shadow.

Then note that the tree lines have the same direction of shadow. If you learn to spot this subtle detail, you can instantly recognize the height of forested areas, pick out single trees and add a lot more perspective into your understanding of these maps.

The aerial on the right shows the location of the photo below. The photographer was standing in the picnic pavillion at the yellow dot, and facing in the direction shown by the blue arrow.

Note that you can see some white sand beach on the other side of the river, which is not shown in the aerial photo. The water was about a foot or two lower in this photo than it was in the aerial. The aerial shows the large white sand beach to the north of the pavillion, but none on the other side of the river.

Sometimes making this connection between these two view helps understand their relationship. As you compare your own vision to the aerial map, you'll quickly get good at interpreting the images.

Also, note the area of black mud. This may be water only an inch or two deep, or it may be the sticky stuff. When the water is up, you can know that these black spots and areas are some of the deeper spots.

This is unavoidable. When the airplane is taking these photos, they fly in a pattern called "mowing the lawn". The photos are then aligned up much like a tile floor. Sometimes there can be a slight mis-alignment, or sometimes (as in this case) the photos may have been taken at different times or days. It could also be caused by a variation in processing the film. Whatever causes it, it's unavoidable for us.

In the case of the Everglades Area 3a map offered here, there are differences because the photos were taken in different seasons, and there was an actual color variation in the vegetation.

When the water is down, a trail will dry up. Sometimes they grow over with vegetation. When this happens, you have to pay close attention to find the trails in the aerial.

"A"
In the aerial to the right, note there is a subtle trail showing, with some "puddles" in it. When the water is up, this is a trail around the edge of Puzzle lake. But with the water down, it's dry. There will be a certain season when the water level is just right, and this trail will look like the one pictured above with a couple inches of water hiding in the grass.

"B"
Look real close. See how this one is two trails running parallel? This is a levee. The trails are the result of the digging to build the levee.

Not really difficult. The tall grass is a nice even texture. Open water is dark. Tree heads and brush heads show as green with different textures. The tree heads will have a rougher texture due to the taller trees making more shadows.

"Slough"
I just want to clear something up. This word is pronounced "SLEW". It is the wet area where there is shallow water, light grass and those little lilly pads. Froggin' country. I hear it pronounced "SLOFF" way too often.

Camps
I'm not entirely sure, but it looks like there is a very small camp in this aerial - The light speck south of the trail along the side of the larger (tree) head.

In this photograph, I was at the location marked with the yellow dot, and facing in the direction of the blue arrow.

You can easily make out the tree head, trail in the slough, and the tall grass on the right.

This is a excerpt from the Everglades Area 3a map, which has some of the camps marked on it, and the camp in the aerial is Duck Camp. You can see the building, large grassy lawn, and the entrance trail.

Sometimes, the camera in the airplane catches a reflection on the water. You can usually see this in a repeating pattern on the maps as they "mow the lawn".

But these reflections are good... Here in Gardiner Marsh north of Catfish Pond from the Kissimmee map, you can see a large white refelction of the sky in the water. If it were not for this reflection, you would not know that that entire field is flooded with a couple inches of water.

The black circles (or white in the reflection) are depressions or little ponds - most just slightly deeper than the surrounding meadow. Deep enough so that the grass can't grow there.

The yellow arrows mark several "bar pits" that the cattlemen have dug to ensure that their stock have water in times of drought. These are easily distinguished by the pit (may be covered with vegetation) with two large piles of dirt on each side. If you hunt the area, you know that these are great vantage points to see the area.

On a few of the maps, you can see reflections of clouds in a large area of water. This is rare, and I do my best to subdue this distracting effect.

Here it is UNsubdued.

Here are some citrus groves near the shore of Salt Lake.

Citrus trees do not like their feet wet, so you can know that this is pretty high ground.

Once in a while, you will see a boat in the aerial. Usually these are kicker boats, they are easy to spot because of their wakes.

This is the entrance to Silver Glen Springs on the western edge of Lake George.

This photo shows some currents in the water and wind marks. I'm not sure, but the wind line in the water that is running parallel to shore may be the wake of an airboat - where it has disturbed the water in the recent past.

Because of the clear spring water, near the mouth of the spring run, you can see areas of white sand on the bottom of the lake along the shore.