[PM2.5] Some Visualization Works

PM2.5 Ground Prediction in North China in 2014


Improving the Accuracy of Daily PM2. 5 Distributions Derived from the Fusion of Ground-Level Measurements with Aerosol Optical Depth Observations, a Case Study in North China
Lv, B., Y. Hu, H. H. Chang, A. G. Russell*, Y. Bai* (2016)
Environmental science & technology, v 50, n 9, p 4752-4759

Video Author: Zhu Deng


Road Pollution Emission in Beijing
(Full Screen / Phone)


 

AOD (MODIS Aqua/Terra) in China


END

[GIS/FCD/Map-Matching] Map-Matching using Yingyan Trace by BMap API

Map-matching algorithms integrate positioning data with spatial road netwok data to identify thr correct link on which a vehicle is travelling and to determine the location of a vehicle on a link. Various map-matching algorithms has been derived from literatures.

BMap recently  released a service named Yingyan Trace, which offered users APIs to upload positioning points, generate and manage traces, and map discrete GPS points to continuous trajectories based on road network.

Preparation

Floating Car Data

Floating car data (FCD) is collection of GPS records about driving status, regularly sampled from GPS equipment in vehicles.

GPS records of a taxi on Nov. 18th, 2014, were used to this case study.

ID: 1379

Records in total: 616

While adjacent points are lined, lines do not coincide with road network.

BMap API Key

Create an application on BMap API Console, and get a API key.

 

UPload

 API Description

http://lbsyun.baidu.com/index.php?title=yingyan/api/v3/trackupload

addpoint - Upload a single point

Interface Description
upload a track point for an entity

Request URI
URI:http://yingyan.baidu.com/api/v3/track/addpoint

HTTP Request Mode
POST

Request Parameter


Return Value
Uploading

Transformat records to wget post request:

Example:  wget –post-data=”ak=0QG***SRL&service_id=13**16&entity_name=1379&longitude=116.***090&latitude=39.***810&loc_time=1479258504&coord_type_input=wgs84&load= ” http://yingyan.baidu.com/api/v3/track/addpoint

 

Manage

Trace Management Console

Map-Matching: tied road network

DOwnload

API Desctiption

http://lbsyun.baidu.com/index.php?title=yingyan/api/v3/trackprocess

gettrack - trajectory correction

Interface Description
Real-time query for an entity within a period of time travel information: from the end, the total mileage, fees mileage, track point list. Support for track denoising, pumping thin, tied, mileage compensation and so on.

Request URI
URI: http://yingyan.baidu.com/api/v3/track/gettrack

HTTP Request Mode
GET
Downloading

Request following url and get a json file with map-matching results in return:

http://yingyan.baidu.com/api/v3/track/gettrack?ak=0QG***SRL&service_id=13**16&entity_name=1379&start_time=1479258504&end_time=1479344904&is_processed=1&process_option=%22need_mapmatch=1%22&sort_type=asc&page_size=5000

Visualization in ArcMap

[Preface] Do Not Go Gentle into That Good Night

Do not go gentle into that good night,
Old age should burn and rave at close of the day;
Rage, rage against the dying of the light.

Though wise men at their end know dark is right,
Because their words had forked no lightning they
Do not go gentle into that good night.

Good men, the last wave by, crying how bright
Their frail deeds might have danced in a green bay,
Rage, rage against the dying of the light.

Wild men, who caught and sang the sun in flight,
And learn, too late, they grieved it on its way,
Do not go gentle into that good night.

Grave men, near death, who see with blinding sight
Blind eyes could blaze like meteors and be gay,
Rage, rage against the dying of the light.

And you, my father, there on the sad height,
Curse, bless, me now with your fierce tears, I pray.
Do not go gentle into that good night.
Rage, rage against the dying of the light.