Wednesday, April 18, 2007

Datum used for LONG and LAT in PCCF

Question

In the PCCF+ 4h program - I know the longtitude and latitude format is xx.xxxxxx and -xxx.xxxxxx, respectively, but what Datum was used for the LONG and LAT? Options would be NAD83 or NAD27?

Answer

From the reference guide for the PCCF & PCCF+ (Statistics Canada Catalogue 4 no. 92F0153GIE):

2001 Census geography features

* Within major urban areas, postal code address ranges are linked to the National Geographic Base (NGB) and wherever possible, a block-face link is identified.

* The 2001 postal code conversion process has produced some cases of reduced data quality. A part of the process generated cases where a postal code was assigned to all blocks located along a road. This occurred when a postal code could be geocoded to a road but not to a specific address range. The system then assigned the postal code to all 2001 blocks linked to the road identifier. In some cases, especially if the road was very long, this process was not appropriate and has resulted in poorer data quality. 4,522 postal codes in the PCCF were corrected where postal codes were related to ‘Main’ postal delivery installations. The records related to these postal codes were re-geocoded so that they are linked to the correct 2001 Census geography. Another group of records (associated with 40 postal codes) with incorrect census subdivision linkages in the province of Québec were also re-geocoded and corrected in the PCCF.

* A geographic unit, the block, has been added to the standard hierarchy.

* A statistical area classification code (SAC) has been added to the census subdivision.

* All the spatial information is now based on the North American Datum of 1983 (NAD83).

1 comment:

  1. Hmm is anyone else experiencing problems with
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    Any responses would be greatly appreciated.

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