Loading in 2 Seconds...
Loading in 2 Seconds...
Spatial Analysis in Government Lecture 2- Data & Information. By Guy Thigpen, M.Phil., MUSA. Purpose of Lecture. Review the Data and Information contained in GEODB2 Explore an example (ULRS) of the information available in the data warehouse Examine the data structure of a parcel layer.
By Guy Thigpen, M.Phil., MUSA
Review the Data and Information contained in GEODB2
Explore an example (ULRS) of the information available in the data warehouse
Examine the data structure of a parcel layer
Data and Information
282 feature files (tables, points, etc)
20 departments provide information
26 geodata folders with additional feature files
ESRI Arc GIS Server 10.1
Some of the services that we provide include, City Aerial Photography, City Hybrid Map, Parcel Layer, Building Footprint Layer, Septa Lines etc.
All these services can be overlaid upon each other according to the user's choice in any web application or desktop around the city.
Pictometry is the leading provider in digital, geo-referenced, oblique aerial imagery and innovative geospatial technologies.
Shot straight down and oriented North-up.
shot at a 40~45 degree angle.
Individual image is available from North, South, East or West.
RESOLUTION:Pictometry offers two levels of resolution, “community” level and “neighborhood” level. The average resolution of oblique imagery at community level (shot from around 4,500 ft) is 1-foot per pixel, and at neighborhood level (shot from around 3,500 ft) is 4-inch per pixel.
DATE/ TIME STAMP : Each image is date and time stamped with the time of capture as reported by the time information transmitted from the Global Positioning System.
The oblique imagery is captured for the City of Philadelphia, including
With Pictometry Electronic Field Study (EFS) software, licensed users are allowed to view and work with the aerial images contained in the Pictometry Image Library
The easiest way to create a connection to the central data warehouse, is by using ArcCatalog and connect to the ArcSDE application server (aka. Geodb2). Geodb2 will broker all your operations to the database.
2) Connecting with Oracle Client:
The central warehouse is in essence an Oracle database, and for power users out there who perform more complex operations and queries, you can connect to the warehouse directly using any Oracle Client .
GIS Spatial Data Sharing and Distribution
Group structure with restrictions:
The foundation of an analysis include DATA and INFORMATION.
The City of Philadelphia has solid foundation of data and information.
W = Wisdom
U = Understanding
K = Knowledge
I = Information(URLS parcel layer and batch geocoder)
D = Data(various shapefiles geospatially located)
DATAPROCESSING: Data is uploaded, stored and collated to be available as data or information
Programs and projects produce data
Open Data Philly
Programs/projects are required or encouraged by federal, state, and local sources to collect data
carried out by contractors and city agencies
A simple task – displaying an address spatially
What do we know about an address?
Incoming addresses are scrubbed to one or more ADDRESS_IDs
For each ADDRESS_ID, assigned to active DOR parcel
!! Not every ADDRESS_ID can be associated with a parcel !!
Process of geocoding
Process of address standardization
Exposed through various means
(!!! after migration to ArcGIS Server, some functionality was lost!!! )
Mimic three basic ways of retrieving information from the web services
- by address
- by parcel #
- by account # (topic key)
~corresponds to 3 ways of organizing the data
Consistency - some legal descriptions do not indicate
streets and just use bearings where others do indicate the streets with the bearings.
Example- South 03 degrees 42 minutes 30 seconds East
LO =N 55º43’59” W
OL =S 55º43’59” E
Each Segment should have bearing
Angles in Bearings are never greater than 90º
Bearings are referenced from North or South
Four predefined ways - South to East,
South to West
North to East,
North to West
A Parcel Should have Bearings either in a clockwise or
Minutes & Seconds should not be greater than 60º
bL = S 15º21’45” W
Lb = N 15º21’45” E
gL = N 60º10’25” W
Lg = S 60º10’25” E
Either – 74.417’
Or – 74’5”
We will discuss the challenges and analysis that led to the implementation of the ‘Front Door’