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I created a shape in OpenJump and exported it to shape(ESRI) file and then imported it to SQL2008 via shape2sql ,

the problem is that it shows bigger than what I want,

In OpenJump it shows 1meter for a small shape,but when I map it to real world map,it shows 100km.

I noticed that my problem is setting SRID or projection mode, as I know there are some Projection Mode, what is the best Projection Mode for drawing a building or factory.

Area about 20m^2 to max 100.000m^2 , Width about 4Meter to 1000Meter, Length about 4Meter to 1000Meter.

It is for World Wide users , but every user just have a map of his Home/Factory.

What SRID should I have to set ?

Ian Turton
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AliRezza
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  • how long is a piece of string? It really depends what area of the world you are in. You should at least add that to the answer – Stev_k Dec 08 '11 at 14:26
  • I added the Area , Area is a building or factory , it could be variable,but I think max is 1Km. – AliRezza Dec 08 '11 at 14:37
  • this doesn't make any sense. Where in the world are you mapping. That will affect the projection – Stev_k Dec 08 '11 at 14:42
  • it is world wide. – AliRezza Dec 08 '11 at 14:45
  • One of the more popular and commonly used projections is WGS84. Also known, including in SQL 2008, as ESPG:4326. – CatchingMonkey Dec 08 '11 at 15:01
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    @ASP, WGS is not a projection, it's a datum. See http://gis.stackexchange.com/questions/664/whats-the-difference-between-a-projection-and-a-datum for the difference. – whuber Jan 07 '12 at 15:57

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This sounds more like a scale problem than a projection problem to me. Probably you are already working in WGS84 Lat / Long projection which is what you need to map the whole world (SRID is EPGS: 4326). I am guessing the problem is that you are not zooming in enough in Open Jump therefore your shape is covering the whole screen, which could easily be hundreds of km across, even for a small shape.

It sounds like you need to get a better understanding of scale. If the shape you draw in OpenJump is only 4cm across, it will represent in reality a much larger area (depending on what scale the map is currently set to). Probably you need to create shapes over an existing background map - that will allow you to represent the actual sizes of shapes on the ground, and get the correct sized shape in SQLServer.

I'm sorry if I'm being too basic, but it seems from your question that you're not familiar with GIS concepts.

Stev_k
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  • I dont know anything from GIS,you are right that my problem is scale, when I draw it in OpenJump,a shape is between longitude 4 and 5 , when I map it to real world map,it shows 1 degree equal to 111km. – AliRezza Dec 08 '11 at 15:12
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    That sounds about right. The whole circumference of the earth is 360 degrees, at at the equator, 1 degree is circumference of earth in km / 360. This is one of the problems with the EPSG 4326 lat long projection - distances are not uniform all over the earth surface. This is easier to understand if you imagine that at 180 degrees north (north pole) the circumference around the earth will be a few cm, whereas at the equator it is thousands of km. Why do you need to draw your buildings in openjump. Presumably you know the co-ordinates, so why not import directly? – Stev_k Dec 08 '11 at 16:03