Thursday, September 24, 2009

Township and Range Updated

About twice each year, the Earth Point gets new township and range data from BLM. However, this spring, the data was not ready, so it has been almost a year since the last update.

Included in today's update
1) The coverage of quarter-quarters is expanded by about 20%, but within these areas, there are still quite a few gaps.
2) Alaska sections are correctly located. Previously, some of the BLM coordinates were based on the NAD27 datum, which led to a displacement of several hundred feet when plotted on the WGS84 Google Earth.
3) New section coverage for southwest Alaska.
4) Better section coverage along the California coast line.

Note: the resolution of the following illustrations is 1/10 of a degree. There are many updates to sections and to corners that are not shown here.

New BLM Quarter/Quarters
Existing quarter/quarters are shown in green. New quarter/quarters are light green. There are often gaps within the green areas. There is no quarter-quarter coverage in Alaska. Click for larger image.

New BLM Sections Alaska
Existing sections are shown in dark purple. New sections are light purple. Click for larger image.

New BLM Sections
Existing sections are shown in dark purple. New sections are light purple. Click for larger image.