Public Lab Research note

Social & Technical Problems of Mother's Day Grassroots Mapping

by eymund | May 12, 2014 00:19 12 May 00:19 | #10465 | #10465

Mother's Day, 11 May 2014

Abigail and Eymund tested Public Lab's new 7 ft Delta Kite in Prospect Park on Sunday. This was part of an ongoing Gowanus CSI (Creek Scene Investigation) research project to map all the historic streams and springs of the Gowanus Watershed.

Based on an 1865 pre development survey, Brooklyn's Prospect Park was built on a complex of artesian springs and wetlands which are speculated to be the headwaters of Gowanus Creek, with the springs historically feeding the now landfilled Vechte's and Brouwer's Brooks that used to run through Park Slope towards the Gowanus marshes.


1865 Frost Survey of Prospect Park showing springs and wetlands in Prospect Park, with streams modeled off the 1782 British Headquarters Map (Gowanus CSI research)


As CSI Gowanus' team of child detectives had observed a network of suspicious puddles in Prospect Park's North Meadow, the Forensics Team decided to try to capture high resolution "grassroots mapping" of the meadow to better understand clues in the patterns of grass types and soil dampness.

The research question was whether these springs still existed, and whether some of them had been diverted into the adjacent Prospect Park West combined sewer system, causing polluting sewage overflows into the Gowanus Canal Superfund site.


The 2010 City Base Map aerial is good - but we needed higher resolution seasonal images to locate the exact extent of the suspected wetland soils.


Puddles, bare soil and different vegetation types give clues to the former wetland areas


A small leaf plant, tentatively identified as Polygonum or Prostate Knotweed seems to thrive on the oxygen deprived soils of the wet areas


The Grassroots Mapping goal: take high resolution aerial photographs of the finer leafed plants to see if they correspond with a pattern of hydric or wetland soils.


The new 7 foot wide delta kite being tested

The kite handles extremely well, but wind speeds were averaging around 5 miles per hour in the North Meadow at 10 am. Based on flight tests, the kite needs a minimum of 10 miles per hour to get sufficient lift to carry the camera rig.


Prospect Park Mother's Day Wind Profile

The wind only started picking up to 7 miles per hour around 1 pm, and was still uneven. As Sunday was a preliminary site scoping test, we decided we would try again next weekend at around 4 pm, during the late afternoon, when winds seem to pick up and the sunbathers that start showing up around noon might be less of an obstruction.

We were also testing a new camera, a recycled Canon SD800 picked up for $10 at the Lower East Side E-Waste Recycling Center in Gowanus. We successfully loaded the CHDK hack script on the sim card that morning, programming it to take pictures every 15 seconds.

The camera was left on "Auto" mode, which proved inadequate for eliminating motion blur in the first run test shots. During the next run with this camera, we will set it to Manual Program Mode with higher ISO (400) and faster shutter speeds.


Canon SD 800 motion blur problem with default Auto mode


Canon SD 800 does a reasonable job of capturing moisture patterns for $10

The biggest grassroots mapping "problems" were not technical but social.

It turns out that rainbow colored kites are like honey and bees for the local kids.

We will need extra volunteers on next outing just to handle requests from the crowds of aspiring grassroots mappers.


There is also a window of time between 12 pm and 3 pm when the meadow suddenly becomes very crowded with sun bathers and family picnics.


It would be interesting to map meadow usage with easier to control balloons over different time intervals to replicate some of the social insights from William Whytes's The Social Life of Small Urban Spaces for Prospect Park.

In low wind conditions, sprinting between sun bathers to keep the kite aloft could become a social problem.


The other unusual problem we ran into is that local children would play with the spare kite rigs while we were away testing kites in other parts of the meadow.


Smiling... but not for long.

In this particular scenario, this aspiring grassroots mapper put the kite reel on his head.

By some strange miracle of medical physics, he managed to slip the reel around his neck.

The problem was that once around his neck, the kite rig refused to slip back up around his head. After multiple tugging attempts, the rumor that children's skulls are malleable play dough proved untrue. The reel will now have to be sawn off to avoid permanent Pteromerhanophobia (fear of kites, flying objects and Grassroots Mappers)

Technical note # 13: Do not stick head through kite reel..

Despite not capturing the "grassroots" images we were seeking, we had a successful test run with testing new gear, and gained valuable social ecology insights. We are now one step closer in the ongoing CSI investigation to find the true sources of the Gowanus Canal...


Technical Note # 13a Update: Mother reports that kite reel was wiggled off child's head using liberal amounts of Earth Balance (Vegan butter alternative).

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