feinstaub-map
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opendata-stuttgart
Set realistic value range for color gradient
Currently the color range spans dynamically from 0(green) to the highest value(red). This leads to most of the cells showing green, even if they are over the threshold, when some sensor reports weird, high values.
How to fix it:
- Define a hard color range with proper thresholds.
- Don't use the data from the PPD42NS sensors for the color range, because they are not reliable.
I'd be happy to implement this, somebody just needs to tell me some thresholds (Grenzwerte) for the data from SDS011. I can then also add a useful legend.
Hey rash!
On 22.11.2016 14:24, rash wrote:
Currently the color range spans dynamically from 0(green) to the highest value(red). This leads to most of the cells showing green, even if they are over the threshold, when some sensor reports weird, high values.
How to fix it: - Define a hard color range with proper thresholds. - Don't use the data from the PPD42NS sensors for the color range, because they are not reliable.
True, this is necessary. Rajko has some forks running here: https://www.madavi.de/ok-lab-stuttgart/
can you please update to get data from cached json? // var URL = 'https://api.luftdaten.info/v1/now/'; var URL = 'https://www.madavi.de/sensor/feinstaub-map-sds/data.json';
I'd be happy to implement this, somebody just needs to tell me some thresholds (Grenzwerte) for the data from SDS011. I can then also add a useful legend.
Legend values for SDS sensors, which are relevant: 50 µg/l is the official threshold (as the mean over day), from there on it should be "alarm color", max. measurement value is 1999.
BTW, red-green blindness is an issue, maybe take blue (= clean air) to red, if possible.
So, here is my suggestion: 0 blue #00000FF 50 blue+red RGB #FF00FF 2000 red
maybe brightness can be added, I tried for example 0-50 #00000FF #0000055 50-2000 #5500000 #FF00000
0-50 #FFFFFF #00000FF 50-2000 #FF00000 #0000000
then it is blue/red according to threshold, and brightness tells you "how much away from it".
50-2000 may be non-linealy scaled, as 1000 should be the max observed (e.g. at Silvester), everything else is a smoker directly blowing into it...
One issue we found is, that the map does not work on any mobile browser. Is there any chance for this? Do you have an idea why it might not be working?
What browsers did you test it on? The number panel does not work, because it does not listen on touch events, but the map should render (it does on my Android/Chrome).
Hi rashfael,
would be nice, if you could change the data path to the cached version (sometimes timeout of 10 sec. is reached). The actual map shows all sensors. A map with a selection of sensor type (PPD42NS with parts per liter, SDS011 as default with µg per m3, DHT22) would be nice.
For the SDS011 possible threshold values could be: Green 0-40 Yellow 41-60 Orange 61-80 Red 81-1999
Threshold values for the PPD42NS are difficult. For this sensor the actual solution works.
For the DHT22 the hexagons could be gray and mouseover shows the values for temp and humidity.
Is it possible to "activate" touch events? Touch should be the same like mouseover, showing the values of all sensors in the hexagon.
What is with values bigger than 180 in CAQI? I would like to show when a value is very bad (180-1999)
the >180 value indicates "this is very bad and shouldn't happen"
no reason to say this is very very bad and shouldn't happen
Yes, but it has happend and i what to see how bad this "shouldn't happen" is
if you change the scala: 180-200 200-500 500-1999
the statement is: 190 isn't that bad it could be worse
So you want to show the reality or just shock people how bad everything ist?
But maybe we can do something like:
- 0-25
- 25-50
- 50-90
- 90-180
- 180-1999 (maybe in a color which is not in the CAQI scale)
The CAQI scale is less strict than the one ricki-z suggested earlier:
Green 0-40 Yellow 41-60 Orange 61-80 Red 81-1999
@ubahnverleih the scale you posted is exactly the CAQI Scale for PM10: 0-25: Very Low (dark green) 25-50: Low (light green) 50-90: Medium (dark yellow) 90-180: High (orange) 180+: Very High (Dark Red, White Font)
And the reason for no range after 180 has nothing to do with shocking the people. This scale is derived from the WHO airquality guidelines. And if you believe in scientific studies this is how bad it is (extracted from the guidelines) :
They invested some toughts in the developement of the CAQI: http://www.airqualitynow.eu/download/CITEAIR-Comparing_Urban_Air_Quality_across_Borders.pdf (and eu funds :P)
i dont see a point in not showing values above 180. its the measurement and its interesting.
the real questions are: what is the purpose of the scale? who is the audience / has the audience a profound knowledge of air quality?
should it just be visualisation of the measured value, then a linear scale from zero to the maximum expected value (250, 300, you should have enough data to get a good value) is the way to go
but if the purpose of the scale to set the measured value in a context of health impacts. A scale based on an air quality index provides this (values 180+ = health impacts)
my oppinion is: dont adjust according to the audience. otherwise everything gets to a level of complete non-understanding (i.e. wide mainstream media) . so it would boil down to a scale of : red, yellow, green.
thats imo not the purpose of the project. the purpose is to build a knowledge. this is a scientific approach with near-scientific measures. so why not just stick with the raw truth?
