[GRASSLIST:3178] help - creating a new region

[uleopold]

Dear list,

I guess this is a very simple question but I cannot find exact help in the 
manuals etc..

I try to create my region settings for the Netherlands. Here a 
stereographic projection with the bessel elipsoid is used.

When it comes to the following questions in GRASS5 I do not exactly know 
what to fil in:

- Enter Central Parallel [lat_0] (0) : 52.15616055 deg ??

- Enter Latitude of True Scale [lat_ts] (0) :  ??

- Enter Central Meridian [lon_0] (20E) : 5.38763889  deg ??

- Enter Scale Factor at the Central Meridian [k_0]  [1.0000000000]: 
0.999907900838 ??

- Enter plural form of units [meters]: meters (that's clear)

Thanks for you attention.

Ulrich


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Geodetic Datum Transformation Parameters

>From NIMA 8350.2   4 july 1997 and HTW


Bursa-Wolf Transformatie Parameters  between Netherlands RD-system 
(stereographic) and WGS 84

Shift: X +565.040 m    Rotation    X  0.00011372 deg
       Y +49.910  m                Y -0.00009992 deg
       Z +465.840 m                Z 0.00051903  deg
Scale Difference:     0.0000040774

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Netherlands RD-system (STEREOGRAPHIC):
System Parameters:

Longitude of origin:    5.38763889  deg
Latitude of origin:     52.15616055 deg
False Easting:          155000.000  m
False Northing:         463000.000  m
Scale reduction factor: 0.999907900838


Ellipsoid Parameters: Bessel 1841

Equatorial Radius:  6377397.155 m
Polar Radius:       6356078.963 m
Eccentricity:       0.0816968312225275
Flattening:         0.0033427731821748
Flattening inverse: 299.1528128


Spherical Model:  Gaussian

Radius      6382644.571 m
Latitude    52.15616055 deg

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WGS 84:

System Parameters:  p.e.  Zone 31
Longitude of origin    3.000      deg
Latitude of origin:    0.000      deg
False Easting:         500000.000 m
False Northing         0.000      m
Scale reduction factor 0.9996


Ellipsoid Parameters:  WGS 84

Equatorial Radius:    6378137.000 m
Polar Radius:         6378137.000 m
Eccentricity:         0.0818191908426215
Flattening:           0.00335281066474746
Flattening inverse:   298.257223563


Spherical Model:  Gaussian

Radius      6356752.314 m
Latitude    0.000       deg

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Testdata

RD/bessel input            UTM/wgs84 output

155000.00     463000.00    663303.930     5780984.291    zone 31
176543.00     465432.00    684756.535     5784124.081    zone 31
247053.00     535311.00    348445.554     5852083.900    zone 32

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_______________________________________________

Ulrich Leopold MSc.

Department of Physical Geography
Institute for Biodiversity and Ecosystem Dynamics
Faculty of Science
University of Amsterdam
Nieuwe Achtergracht 166
NL-1018WV Amsterdam

Phone: +31-(0)20-525-7456 (7451 Secretary)
Fax:   +31-(0)20-525-7431
Email: uleopold at science.uva.nl
http://www.frw.uva.nl/soil/Welcome.html

Check us also out at:
Netherlands Centre for Geo-ecological Research
http://www.frw.uva.nl/icg