In surveying, cartography, and land-use planning, two North American Datums are in use for making lateral or "horizontal" measurements: the North American Datum of 1927 (NAD 27) …

2018年7月12日 · The NAD 27 was based on the Clarke Ellipsoid of 1866 and the NAD 83 is based on the Geodetic Reference System of 1980. The NAD 27 was computed with station …

The North American Datum of 1983 (NAD 83) is a unified horizontal or geometric datum and successor to NAD27 providing a spatial reference for Canada and the United States. NAD83 …

2019年9月22日 · 这个 1927年北美基准（NAD27） 是北美主要的三个大地基准之一。 NAD27使用了所有使用最小二乘平差收集的水平大地测量。 该基准面采用克拉克椭球面1866年，在堪萨 …

2011年7月28日 · NAD 27 vs NAD 83. The North American Datum, or NAD, is the official geodetic datum that is prevalent in North America. There are two kinds of datum used in North America, …

2018年7月12日 · What are NAD 27 and NAD 83? The North American Datum of 1927 (NAD 27) is "The horizontal control datum for the United States that (was) defined by (a) location and …

Replaced by NAD27(76) (code 4608) in Ontario, CGQ77 (code 4609) in Quebec, Mexican Datum of 1993 (code 4483) in Mexico, NAD83 (code 4269) in Canada (excl. Ontario & Quebec) & …

It is the reference ellipsoid of the datum known as the North American Datum of 1927 (NAD27), but it is not the datum itself. For the Clarke 1866 spheroid to become NAD27, the ellipsoid of …

2022年9月23日 · 北美基准面 1983 (nad 83) 是统一的水平基准面或几何基准面，是 nad27 的后继基准面，为加拿大和美国提供空间参考。 nad83 通过使用来自地面和多普勒卫星数据的一组 …

NADCON is the Federal standard for NAD 27 to NAD 83 datum transformations. NADCON Documentation Download the NADCON program and Data Grids for PC execution.