This is one of the robots used in the Brooklyn Atlantis project. We've recently fit it with YSI 600r water quality sonde, which gives us a few measures of water quality, such as pH, dissolved oxygen, conductivity, etc. Both the water quality data and the GPS are logged as the robot moves throughout the canal. We've also put a DSLR camera with an automated pan-tilt mechanism on top to get some interesting photos.
My attempt and results
Overlaying the water quality data with the position data, we can see some interesting trends;
Noting that the flushing tunnel was on at the time, we see a higher dissolved oxygen as we travel towards it (located at the top-most part). The water from the flushing tunnel is also a bit saltier and cooler when compared to the rest of the canal (as expected)
As Eymund has pointed out, there is a somewhat unexpected spike in the dissolved oxygen right around where the Union St. bridge is. We'll be trying to figure out what is going on there.
Below is an example of six photos stitched together into a single panorama.
With the correct viewer, one can pan the view, similar to google street view. We've posted the image on 360cities, but as I check it now, it doesn't seem to be loading.
Questions and next steps
What's with that anomalous spike in dissolved oxygen?
We'll be doing more water quality testing in the coming days and analyzing the data.
Thanks to Ben High for helping to develop the camera rig and Angela Chen for helping with the water quality testing.
This project was developed at New York University Polytechnic School of Engineering with the support of the National Science Foundation.
Christopher Swain, the first person to swim the entire length of the Gowanus Canal in over a century is also getting similar Canal length sensor fluctuation results in October 2015.
His body suit data is also showing a very slight unusual Ph and Temperature fluctuation at the Bayside Fuel depot area of the Union Street Bridge. Note that the map shows two different swim date readings (April and October), which should not be confused as temperature differences.
We can only continue speculating and researching what may be causing these fluctuations. Besides floatable pollutant or bathymetric causes, this could also be a freshwater seepage point for the long lost Sassian Brook which can be currently heard flowing in the sewers at Wyckoff and Hoyt Street. It may also be Bergen Creek, which frequently floods basements on Sackett Street.
2011 - 28 August; Hurricane Irene - Bergen Creek being pumped out of basements on Sackett Street
Circa 1770's map of Gowanus Creek and Sassian Brook, from the Fort Green Map, Office of Chief of Engineers, War Department, US Library of Congress
The Brouwer's Mill Bridge shown on the map is about a 100 feet north of where Union Street Bridge is today.
The temperature fluctuations we are seeing may be surviving fragments of the streams shown on the map.
A 8 July 2012 balloon aerial of the data fluctuation site, showing the Bayside Fuel Depot Canal site edge just north of the Union Street Bridge:
This data clue justifies further research on Union Bridge area to pinpoint what is causing the data fluctuation. Should an actual fresh water inflow be found, opportunities for diverting those streams out of the City's overloaded combined Bond Street sewer system should be explored.
Some rough field research notes of the area from a 1782 Military Map
The map below shows a balloon aerial of the Brouwer's Bridge area in 2011.
The 8 July 2012 Balloon Union Street Bridge Mapping Team
Accidental data pieces - community generated grains of sand, which accumulating together, start creating a broader beach of knowledge.