Conventional transformations between datums use only a relative offset between different frames of reference, but no relative rotation. Is this really enough?
The relative offsets in terms of a 3-Parameter Datum Shift is because the single board computer (sbc) in the old Magnavox 1502 Transit Satellite Doppler Receivers could only accomodate that simple model in 1972 when they were put into production. When the WGS72 Datum was declassified in 1976, the 1502’s were declassified and sold to the public. THAT’s when people started to learn what Datums were all about. Considering that before then, the fanciest (absolute) positioning hardware was a First-Order Astronomical Theodolite with a radio chronometer and impersonal micrometer that after two evenings of observations got you a position to +/- 100 meters. It is enough for small regions and countries if you’re delivering 155 mm Howizer Cannon fire or sending Cruise missiles with High Explosive Warheads. It is not generally suitable for geodetic applications and many GIS applications if you need an accuracy better than +/- 25 meters. The “free” stuff from NIMA is intended for destroying large g
The relative offsets in terms of a 3-Parameter Datum Shift is because the single board computer (sbc) in the old Magnavox 1502 Transit Satellite Doppler Receivers could only accomodate that simple model in 1972 when they were put into production. When the WGS72 Datum was declassified in 1976, the 1502’s were declassified and sold to the public. THAT’s when people started to learn what Datums were all about. Considering that before then, the fanciest (absolute) positioning hardware was a First-Order Astronomical Theodolite with a radio chronometer and impersonal micrometer that after two evenings of observations got you a position to +/- 100 meters. It is enough for small regions and countries if you’re delivering 155 mm Howizer Cannon fire or sending Cruise missiles with High Explosive Warheads. It is not generally suitable for geodetic applications and many GIS applications if you need an accuracy better than +/- 25 meters. The “free” stuff from NIMA is intended for destroying large g
Related Questions
- Conventional transformations between datums use only a relative offset between different frames of reference, but no relative rotation. Is this really enough?
- How is the Chevy Volt different than conventional hybrids, like the Prius?
- How is UCG different from conventional coal mining and surface handling?
