Public Lab Research note


ShowerKAP II

by cfastie | July 06, 2013 23:11 | 3,182 views | 0 comments | #8727 | 3,182 views | 0 comments | #8727 06 Jul 23:11

Read more: stable.publiclab.org/n/8727


Image above: My minimal KAP rig with ShowerKAP in action. This was during the landing after a 70 minute mapping flight including about 15 minutes of fairly hard rain. The Canon S95 camera was dry and happy. This is a false color infrared image (NBG) from an infrablue camera (the only camera I had handy).

The ShowerKAP was invented in the field last year, but not fully tested until this week. Like last year, there was a narrow window for kite mapping my tundra study plots and the weather was not very good for flying when it had to be done. It never rained during last year’s flight using the ShowerKAP, but this year it started raining about 40 minutes into the flight. My $400 Canon S95 was in the air, but I really wanted to map that last plot. The ShowerKAP is a plastic sandwich bag attached with rubber bands at each corner.

ShowerKAP_Jul04-2013_11_56_41-2.jpg

The Brooxes KAP rig with S95 under a very damp Levitation Delta kite. The wind was cooperative, so I was able to land the rig in my hand, and the long landing legs were not instrumental in keeping the camera away from the wet vegetation. An infrablue photo.

The mapping photos below were taken during the heavy rain. They look a little soft, but they are not much different from other photos from the flight taken before the rain. The softness is apparently due mostly to the high ISO (200), small f stop (f/2.8), and dull light. The shutter speed was 1/500 for all the photos, and motion blur is generally not noticeable. The S95 has a nice wide angle lens, but I zoomed it in two clicks for this flight to 8.56 mm (range is 6.0 to 22.5 mm, or 28 to 105 mm equiv.). That was because some of the plots I was mapping had trees that I had to fly over, and I wanted as much detail as possible. The image below is stitched from several higher elevation photos. Afterwards I brought down the kite and captured higher resolution photos which have yet to be aligned.

MA5flat1500.jpg

Several stitched kite photos of plot MA5 (Monahan Flats Above Treeline 5). The corners of the plot are permanently marked with pipes and were marked with pink flagging before the flight. Five spruce seedlings were also flagged before the flight, and are labeled with triangles. The plot is 50 meters on each side and is more or less square. Deviation from squareness is due either to poor original surveying or more likely because these photos were stitched with MS Ice with no georeferencing control.

Vegetation in the northern (upper) part of the plot is head high willow and waist high shrub birch. Vegetation in the southern part of the plot is lichen and low blueberry shrubs on a dry slope.


0 Comments

Login to comment.