arakish

Very Strange Request

Discussion created by arakish on Aug 6, 2010
First, I wish to apologize for a very long first-time post.  However, I reasoned that the more data I can supply, the better others can aid me.  Also, I am not sure I am posting in the correct thread.

I work as a GIST (Geographic Information System Technician) for the State of New Mexico.  I am also attending Central New Mexico Community College for a GIS degree.  I have been scouring the forum boards and ArcHelp and can find no help for a very interesting project.

On another forum board for cartography I frequent, I mentioned how it may be possible to actually define an imaginary world - but defined with real physics - into a GIS program so one could create many layers that are georeferenced into that world's coordinate system.  I received quite a few replies that said it was impossible to do such.  Needless to say, I accepted the challenge.  The name of the imaginary world is "Onaviu".

I realize this strange project has no real world equivalency.  However, I also think this project would make an excellent final project for my GIS curriculum.  I feel, if able, that actually defining an imaginary world into a GIS would show off the full potential of GIS software.

I have been using a limited version of ArcMap (ArcEditor v9.3.1) at home (I have a more advanced version at work, but cannot use it for private projects) and came up with the following strategy.  Below are the PRJ files I wrote in a text editor.

Onaviu Geographic Coordinate System

PROJCS["Onaviu_Cylindrical",
GEOGCS["Onaviu_2025",
DATUM["Onaviu",
SPHEROID["Onaviu_Spheroid",8184996.118,402.984694090]],
PRIMEM["Tanlindon",0],
UNIT["Degree",0.017453292519943295]],
PROJECTION["Onaviu_Cylindrical"],
PARAMETER["False_Easting",0], (I question this due to the shift of the map)
PARAMETER["False_Northing",0], (I question this due to the shift of the map)
PARAMETER["Central_Meridian",0], (I question this due to the shift of the map)
UNIT["Meter",1],
EPOCH[16000022250101]]

Onaviu Projected Coordinate System

GEOGCS["Onaviu_2025",
DATUM["Onaviu",
SPHEROID["Onaviu_Spheroid",8184996.118,402.984694090]],
PRIMEM["Tanlindon",0],
UNIT["Degree",0.017453292519943295],
EPOCH[16000022250101]]

Onaviu Vertical Coordinate System

VERTCS["Onaviu_2025",
DATUM["Onaviu",
SPHEROID["Onaviu_Spheroid",8184996.118,402.984694090]],
PARAMETER["Vertical_Shift",0.0],
PARAMETER["Direction",1.0],
UNIT["Meter",1.0],
EPOCH[16000022250101]]

Of course, I realize the EPOCH may not be needed.  Also, it may be disruptive to ArcMap.  However, it is an arbitrary datum in the following format: HHMMSSYYYYMMDD.  It is a needed datum for updating the planet's and its star's position in space for a new program I am writing.  Also, the Epoch is in Onaviu time (Onaviu has 32 hours/day).

Much of the above data was derived from the following data:

Equatorial Radius: 8184996.118 meters (this is the given data)
Polar Radius: 8164685.183
Volumetric Mean Radius: 8178220.198
Ellipticity: 0.00248148382473662237068795
Inverse Flattening Ratio: 402.984694089689322628723587

(There is much more data for this world, but it is not included.)

Of course, when Onaviu was designed, the person used the Earth as a model.  Needless to say, his original created data was wrong.  I am an amateur astrophysicist with some program writing experience for orbital mechanics, celestial mechanics, gravitational mechanics, and many other sub-fields in astrophysics.  Originally, he had Onaviu's ellipticity equal to 0.00336725.  Onaviu's density was defined as 1.102375 times that of Earth's (6079.596806 kg/m^3) and its rotational period was 115,200 seconds (Earth's = 86,400 seconds).  The problem here is a world with a slightly greater density and slightly slower rotational period would not have an ellipticity that close to Earth's (0.00336725 to 0.003353).  I calculated Onaviu's new ellipticity as listed above using a program I had written using Visual Basic v4 (in DOS/Windows 3.11 days, and it still works in Vista!).  Although there are many other factors involved, density and rotational period will have the largest influence on a celestial object's ellipticity.

Once I had the oblate spheroid definition, I was able to complete all of the calculations needed to define certain points and latlong lengths on Onaviu's surface.  Using Onaviu's orbital obliquity (axial tilt) of 18.25°, I was able to devise the below information.  Trust me, the calculations are accurate within ±5%...  Close enough for me.

NOTE: I used spaces instead of tabs to tabulate, using a monospace font...

ID    NAME                  MTRLEN
0     North Pole            0
1     -90°W                 25713923.3
2     South Pole            0
3     -90°W                 25713923.3
4     Arctic Circle         16105340.2
5     North Sub-Polar       48840980.98    (Tropic of Cancer)
6     Equator               51427846.6
7     South Sub-Polar       48840980.98    (Tropic of Capricorn)
8     Antarctic Circle      16105340.2
9     Prime Meridian        25713923.3
10    180°E                 25713923.3
11    90°E                  25713923.3

ID is the id of the line 
NAME is the applicable line type as it would appear if on the Earth 
MTRLEN is equivalent length of the line on the globe of Onaviu in meters 


POINTID    DDLAT     DDLONG      MLAT             MLONG
0          90        -90         12841019.34      -12856961.65
1          90        0           12841019.34      0
2          90        90          12841019.34      12856961.65
3          90        180         12841019.34      25713923.3
4          90        -90         12841019.34      -12856961.65

5          71.75     -90         10249885.69      -12856961.65
6          71.75     0           10249885.69      0
7          71.75     90          10249885.69      12856961.65
8          71.75     180         10249885.69      25713923.3
9          71.75     -90         10249885.69      -12856961.65

10         18.25     -90         2607106.15       -12856961.65
11         18.25     0           2607106.15       0
12         18.25     90          2607106.15       12856961.65
13         18.25     180         2607106.15       25713923.3
14         18.25     -90         2607106.15       -12856961.65

15         0         -90         0                -12856961.65
16         0         0           0                0
17         0         90          0                12856961.65
18         0         180         0                25713923.3
19         0         -90         0                -12856961.65

20         -18.25    -90         -2607106.15      -12856961.65
21         -18.25    0           -2607106.15      0
22         -18.25    90          -2607106.15      12856961.65
23         -18.25    180         -2607106.15      25713923.3
24         -18.25    -90         -2607106.15      -12856961.65

25         -71.75    -90         -10249885.69     -12856961.65
26         -71.75    0           -10249885.69     0
27         -71.75    90          -10249885.69     12856961.65
28         -71.75    180         -10249885.69     25713923.3
29         -71.75    -90         -10249885.69     -12856961.65

30         -90       -90         -12841019.34     -12856961.65
31         -90       0           -12841019.34     0
32         -90       90          -12841019.34     12856961.65
33         -90       180         -12841019.34     25713923.3
34         -90       -90         -12841019.34     -12856961.65

POINTID is the point identification I assigned for my use
DDLAT is the decimal degree location of the point in latitude; from the equator, positive is North, negative is South
DDLONG is the decimal degree location of the point in longitude; from the Prime Meridian, positive is East, negative is West
MLAT is the equivalent location of the point in meters latitude; again, positive is North, negative is South
MLONG is the equivalent location of the point in meters longitude; again, positive is East, negative is West

Other Note: Of course, the 180° longitude could also be listed as -180.

If I can do it, attached to this post should be a PNG file which shows the above as depicted in ArcMap.  I want to define the projection files (and et. al.) for this world.  Currently, all I am able to use, until I prove this can be done, is a very simple 7200pxw by 3600pxh PNG file (as shown in the attached PNG file).  Using all these definitions and attributes (I added and edited the attributes), how can I make ArcMap to define these data to make a projection.  Fortunately, I will not have to define any geographic transformations since Onaviu will use only ONE coordinate system, unlike our Earth (and some of its data).  All data will be defined in ONE coordinate system.  THANK GOD!!

Here are the problems.  When I actually direct ArcMap to use the PRJ (specifically the Projected) files as written above, it does not seem the data frame accepts the PRJ file.  Another problem is when I use the Data Frames Properties dialogue box to define the PCS and GCS, ArcMap crashes completely.

Here are my questions:

1) How can I use the above data to get ArcMap to generate a coordinate system for Onaviu?

2) How can I assign this coordinate system when  I re-open ArcMap later?

And the biggest questions:

4) Is there a way I can use ArcMap to export such into formats usable by FOSS4G products such as QGIS, GRASS, et. al.?

I do know many of the FOSS4G software can read an array of formats (even greater than ArcMap), which is very fortunate for this truly off-the-wall project.

Again, sorry for such a long first post.  And thanks for any aid offered.

rmfr

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