I have checked the API reference and the Concepts reference for the Community Analyst API, but I can't see anything that describes the geoprocessing routine that generates the reports. In order to use the API, I need to know what assumptions are being made. For example, in this sample:
are the values merely a summary of the census geographies that fall under the selected polygon, or is a clip taking place? If the latter, is there an assumption that population is regular across the entire census polygon, or is population apportioned based on other variables, e.g., land use.
I suspect I'm just missing a key reference that documents how BA works - can someone please point me in the right direction???
Again, thanks for you help Jason. (another question:)).
Based on what I have read, it seems apparent that USPS ZIP codes are used as a standard geography for summarizing data in Community Analyst. NOT ZIP Code Tabulation Areas (ZCTAs). But I want to be sure that is the case. ZIP Codes or ZCTAs? (If ZIP Codes - how often does Esri update its data summaries/tabulations?)
(P.S. This Esri page contains descriptions of Community Analyst data: http://help.arcgis.com/en/communityanalyst/online/data/data_descriptions.html. When I hover over the geography description for "Census Tract" on the page, it indicates that a tract generally has between 1,500 and 8,000 households. I believe that it should refer to people instead of households. Right?)
Again, thanks for you help Jason. (another question:)).
Based on what I have read, it seems apparent that USPS ZIP codes are used as a standard geography for summarizing data in Community Analyst. NOT ZIP Code Tabulation Areas (ZCTAs). But I want to be sure that is the case. ZIP Codes or ZCTAs? (If ZIP Codes - how often does Esri update its data summaries/tabulations?)
Thanks
Bob, Community Analyst just uses residential delivery zip codes (area/polygon zips) and does not use ZCTAs. ZIP code boundaries come from the NAVTEQ Q4 2011 release for the Esri 2012/2017 data update. Each time there is a new Esri data release there will be a newer zip code vintage.
Community Analyst just uses residential delivery zip codes (area/polygon zips) and does not use ZCTAs. ZIP code boundaries come from the NAVTEQ Q4 2011 release for the Esri 2012/2017 data update. Each time there is a new Esri data release there will be a newer zip code vintage.
Regards, Jason R.
Thanks Again, Jason. I have been diving deep into Community Analyst and questions keep coming up.
I created a 3 mile ring around my home address in Community Analyst Online using "Find Location." I then created a 3 mile ring around my home address in ArcGIS 10.1 (spatial reference WGS_1984_Web_Mercator_Auxiliary_Sphere) using the Business Analyst Evaluate Site tool and uploaded (imported) the shapefile to Community Analyst. The radius of the "3 mile" ring created on the desktop is slightly smaller than that created in CA online, and the reports generated by each are different. Is this a spatial reference issue?
Thanks Again, Jason. I have been diving deep into Community Analyst and questions keep coming up.
I created a 3 mile ring around my home address in Community Analyst Online using "Find Location." I then created a 3 mile ring around my home address in ArcGIS 10.1 (spatial reference WGS_1984_Web_Mercator_Auxiliary_Sphere) using the Business Analyst Evaluate Site tool and uploaded (imported) the shapefile to Community Analyst. The radius of the "3 mile" ring created on the desktop is slightly smaller than that created in CA online, and the reports generated by each are different. Is this a spatial reference issue?
Bob,
Business Analyst Desktop created layers should be in GCS_North_American_1983 though the data frame in the default business analyst map documents are in that web mercator projection.
I tested creating an evaluate site simple two mile ring in BA Desktop and ran a local D&I Report and then uploaded the same ring to BAO/CA and ran a D&I Report. These two reports exactly matched. However when I run an online D&I Report from Business Analyst Desktop the numbers were different from the other two reports so will investigate that.
