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si1242

External Data

posted in KDD CUP of Fresh Air

2018-04-29 08:36

Hi, I share AQ data source & sample code with you.

### Data source
[silam.fmi.fi/index.html](http://silam.fmi.fi/index.html)
>SILAM is a global-to-meso-scale dispersion model developed for atmospheric composition, air quality, and emergency decision support applications, as well as for inverse dispersion problem solution.
...
>SILAM is an open-code system and free for research applications. Contact us to obtain the model.

### Sample code
```python
import requests
# http://silam.fmi.fi/thredds/dodsC/silam_europe_v5_5_1/runs/silam_europe_v5_5_1_RUN_2018-04-27T00:00:00Z.ascii?cnc_PM2_5[0:3:71][0:1:0][205:5:225][230:5:270]
#http://silam.fmi.fi/thredds/dodsC/daily_silam_china_v5_5_1/runs/daily_silam_china_v5_5_1_RUN_2018-04-29T00:00:00Z.ascii?daymax_cnc_PM2_5[0:1:0][0:1:0][0:1:0][0:1:0]

date = '2018-04-29'
# ex)BL0-London
# Actual [lon,lat]
lon, lat = -0.1258, 51.522
# SILAM Grid Map(230,205) corresponds to 'london_grid_000'(-2,50.5)
x, y = int((lon - (-2.0)) * 10 + 230), int((lat - (50.5)) * 10 + 205)

prefix = 'http://silam.fmi.fi/thredds/dodsC/silam_europe_v5_5_1/runs/silam_europe_v5_5_1_RUN_' + \
    date + 'T00:00:00Z.ascii?cnc_PM2_5'

time = '[0:1:119]'
height = '[0:1:0]'
lat_range = '[' + str(y) + ':1:' + str(y) + ']'
lon_range = '[' + str(x) + ':1:' + str(x) + ']'

url = prefix + time + height + lat_range + lon_range
r = requests.get(url)
print(url)
print(r.text)
```

23 comments

Grox

2018-04-30 08:31

si1242 reply Grox

2018-05-02 03:39

Reply

0

Acording to (<a href="http://silam.fmi.fi/thredds/catalog/silam_europe_v5_5_1/runs/catalog.html?dataset=silam_europe_v5_5_1/runs/silam_europe_v5_5_1_RUN_2018-05-01T00:00:00Z">Catalog Services</a>), SILAM system has 720*420 size grid map and it covers below. <blockquote> GeospatialCoverage: Longitude: -24.950000762939453 to 44.95000076293945 degrees_east Latitude: 30.049999237060547 to 71.94999694824219 degrees_north Altitude: 12.5 to 7725.0 Resolution=856.9444444444445 m (positive is up) </blockquote> That is, <ul> <li>Longitude(actual) [-24.95:44.95] is mapped to [0:419] (SILAM Grid Map), </li><li>Latitude(actual) [30.05:71.95] is mapped to [0:719] (SILAM Grid Map). </li></ul> In addition, a notation, such as [0:1:119], is not Python’s slice notation. It means <code>[start:step:end]</code>.