Public Lab Research note

Top 10 tips for winter mapping

by cfastie | December 08, 2012 16:03 08 Dec 16:03 | #5161 | #5161

Toxics Action Center is working on a plan to incorporate Public Lab tools into its work with several communities in Vermont. Aerial mapping could be an important tool for a couple of urgent projects, so they have inquired about the feasibility of balloon or kite mapping in the winter. Aerial photography is quite workable in the winter, but presents a few additional challenges compared to warm season flying:

  • 1. Cold fingers and toes: Fiddling with cameras requires some glove-free fingers, but just for a few minutes, and line handling requires gloves anyway. Just be prepared to stand around in the wind (for kiting), and make sure everyone else is prepared for the weather, especially if you are running a workshop.

  • 2. Cold batteries: Cameras that shoot continuously for two hours in the summer may last only 30 minutes when the temperature is near freezing. So plan for shorter flights. Keep spare batteries warm in a pocket, not in a cold backpack. Or even better, have a second, warm camera ready to go for the next flight.

  • 3. Unplanned landings: Keeping the camera off the ground is critical when there is snow or mud or wet vegetation. Landing legs or a protective camera rig help, but keeping the camera dry could mean flying only when wind conditions are near perfect. In deep snow, it's harder to run upwind to keep a kite airborne during lulls in the wind.

  • 4. Flying weather: Compared to summer, days with suitable wind and light are less common during Vermont winters. So any date chosen in advance for an outing is less likely to have acceptable conditions. Flexible planning is a better strategy than a rigid schedule.

  • 5. Setup: If there is deep snow or soggy vegetation, consider taking a sled or tarp to use as a portable work surface for assembling kites, rigs, etc. or keeping your knees dry during setup.

  • 6. Exposure: Snow is really bright from the air, and cameras assume that scenes are of average brightness. If your camera has an exposure compensation setting, it might help to set it somewhere between +2/3 and +2 to avoid photos in which snow is gray and everything else is too dark to see.

  • 7. Scene details: Winter might be better or worse for certain photography projects. Leafless trees can increase the visibility of buildings or other features, but make the scene dull. Snow cover can obscure some landscape details like vegetation patterns, but highlight others, like topography.

  • 8. Short days: Winter days may be bright enough for good photography only for a few hours at midday. Starting out after lunch might be too late.

  • 9. Low sun angle: Long shadows can make for dramatic aerial photos, but might distract from your objective. For oblique photography on sunny days, shots toward the south could be strongly backlit, for better or worse.

  • 10. Condensation: When it is really cold, after the flight put the camera in a cloth bag inside a plastic bag and expel all the air before bringing it into a warm car, building, or pocket.

Any other considerations?


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