Posts Tagged ‘site exploration’

Ground truth

March 2, 2016

Scouting odonate habitat using Google Earth is quicker and simpler than a site visit, but when you think a new location has potential you still need to “ground truth” what is shown in the remotely-sensed imagery.

For example, the following Google Earth image suggests it should be relatively easy to reach the banks of two tributaries that flow into Dyke Marsh Wildlife Preserve.

DM_RTC

Dyke Marsh Wildlife Preserve | interactive image on Google Earth

In contrast, look at the following photorealistic 32-bit HDR composite image of Dyke Marsh as viewed facing southeast from River Towers Condominiums. The banks of one of the streams are choked with dead vegetation, flattened by a recent flooding rain event. In mid-summer, the same location is likely to be a tough slog due to waist-high vegetation!

A 32-bit HDR composite image created from three photos of Dyke Marsh as viewed from River Towers Condominiums, Fairfax County, Virginia USA, +/- two stops of exposure.

29 FEB 2016 | River Towers Condominiums | Dyke Marsh

Look closely at the preceding composite image. Did you notice the beaver lodge? The George Washington Memorial Parkway appears along the base of the tree line shown in the background. You can see a white vehicle that seems to be driving through the marshland, near the center of the image.

Copyright © 2016 Walter Sanford. All rights reserved.

Pole Road Park

February 29, 2016

Pole Road Park, Fairfax County, Virginia USA.

Pole Road Park is located along Dogue Creek, downstream from Mulligan Pond at Jackson Miles Abbott Wetland Refuge.

Pole Road Park, Fairfax County, Virginia USA.

The Backstory: On Saturday, 20 February 2016, I spent a few hours searching for easier access to Dogue Creek than is afforded by Jackson Miles Abbott Wetland Refuge. Along the way, I discovered Pole Road Park. This location looks like it provides ideal habitat for some species of odonates. More later after further exploration.

Copyright © 2016 Walter Sanford. All rights reserved.

Mulligan Pond

February 27, 2016

The following photorealistic 32-bit HDR image of Mulligan Pond, Jackson Miles Abbott Wetland Refuge, is a composite of three bracketed exposures, +/- two stops of exposure.

A 32-bit HDR composite image created from three photos of Mulligan Pond, Jackson Miles Abbott Wetland Refuge, Fairfax County, Virginia USA, +/- two stops of exposure.

20 FEB 2016 | Jackson Miles Abbott Wetland Refuge | Mulligan Pond

Jackson Miles Abbott Wetland Refuge is located along Dogue Creek, downstream from the southeastern boundary of Huntley Meadows Park.

The wetland refuge is open to the public, although signs such as the one shown below are a sobering reminder that the property belongs to the U.S. Army. The danger is real, according to John Pilcicki, Natural Resource Specialist, U.S. Army Garrison Fort Belvoir, and visitors should stay on the marked trail.

Signage at Jackson Mile Abbott Wetland Refuge, Fairfax County, Virginia USA.

20 FEB 2016 | Jackson Mile Abbott Wetland Refuge | Signage

Tech Tips: I used my Panasonic Lumix DMC-FZ150 superzoom camera to shoot three bracketed exposures of the same landscape. The camera was set for manual focus at the hyperfocal distance for an aperture of f/4, based upon the instructions provided in the excellent video tutorial by Graham Houghton, “Panasonic Lumix FZ camera easier manual focus method — super point-and-shoot tip.” I used Adobe Photoshop CC (2015) and Lightroom CC (2015) to create and edit a 32-bit HDR composite image of the three exposures: Photoshop was used to create the HDR image; Lightroom was used to adjust the composite image. The final version was exported from Lightroom as a 16-bit TIFF and imported into Aperture for some finishing touches.

Copyright © 2016 Walter Sanford. All rights reserved.


%d bloggers like this: