[GRASS-dev] what is the ideal way to store spatial data

[Boris Avdeev]

Apparently you are not working often in polar areas, so such problem
of spherical coordinates as singularities is not obvious.
Gravitational center, to my understanding, is not an easily defined
point either. Also, from ArcGIS experience, on-the-fly reprojection is
quite slow process even using most powerful desktop.

Boris

On Dec 30, 2007 8:12 AM, Gerald Nelson <gnelson at uiuc.edu> wrote:
> Since all spatial data are about describing a specific location on a specific planet, usually earth, it would seem that the best way conceptually to store data is with respect to a single easily defined reference point such as the gravitational center of the planet. Any location could then be measured with three values. x,y like latitude and longitude, and z a distance measure from the reference point along a ray.
>
> Projections such as utm, etc, are about how to convert the 3-d data described above into 2-d with a minimum of distortion. Given the speed of modern computers this conversion process ought to be increasingly easy to do on the fly, as needed.
>
> The reason I raise this question is to ask the experts whether it would make sense (for 7.x) to think of a single standard way of storing data in grass and then all operations would do the conversions as necessary? There are (at least) two advantages of this. One is standardization of data storage in a form that is closest to a true representation of the real world. A second is to reduce the potential for confusion/mistakes when data are shared and the metadata are not, or are inadequate. I am continually getting access to data where the units are not clearly defined. But even if they are defined say as some utm coordinate, there must be some error in measurement built in.
>
> Just some thoughts on a Sunday morning.
>
> Regards,
> JErry
> Gerald Nelson
> Professor, Dept. of Agricultural and Consumer Economics
> University of Illinois, Urbana-Champaign
> office: 217-333-6465
> cell: 217-390-7888
> 315 Mumford Hall
> 1301 W. Gregory
> Urbana, IL 61801
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