Latest Contributions by MelitaKennedy

‎06-19-2013

Hi Alan, I can think of two possibilities. Are you equating X = longitude and Y = latitude? When using the Add XY tool, you need to assign the data's current coordinate system. The tool will default to the data frame's coordinate system. Because your points are in lat/lon, you need to assign the appropriate geographic coordinate system. Melita

‎06-17-2013

The online services are using 3857 aka WGS 1984 Web Mercator Auxiliary Sphere for their coordinate system. Your Excel data is almost certainly not using this coordinate system. The Add XY Data tool defaults the coordinate system to whatever the map is using. So it's likely your Excel data is being assigned the wrong coordinate system. Check to see what it should be and assign that when you add the data to the map. ArcMap can project XY data (Excel, csv, etc.) on the fly. Melita

‎06-14-2013

The help for the error says that it includes the issue that Python has encountered. What's the exact text you're getting with the error?

‎06-11-2013

We have some vertical transformation support in the low-level library, projection engine. Our next step is to expose this functionality at the programming level (aka ArcObjects, Runtime) so that internal and external developers can take advantage of it. It won't be in ArcGIS 10.2, but hopefully soon. Melita Kennedy Sr. Product Engineer

‎06-05-2013

My suspicision is that the points are not in the same coordinate system as the imagery. Particularly if you use the Add XY tool in ArcMap, it will default to assigning the data frame's coordinate system to the XY data. If the XY data is not already in that coordinate system, you can get the problem you listed with not being able to view all layers at once. When a coordinate system is assigned as in the Add XY tool, Define Projection tool, or data's property page in ArcCatalog, it updates the metadata only, the coordinate values are not changed. You have to assign the coordinate system that the data is in, then use the Project Tool or let ArcMap project the data on-the-fly to put it into a different coordinate system. If the imagery is in a projected coordinate system, I think the points are lat/lon, a geographic coordinate system. Melita

‎06-04-2013

Hello, Make sure that you have write permissions for the files and the folder that the shapefile is in (that's one reason why Define Projection would not work). Close ArcMap if it's open (we want to make sure that the shapefile isn't locked by being in use somewhere). Use the Define Projection tool in ArcToolbox. You will probably get a warning that the shapefile already has a coordinate system. You can ignore the warning. Set the coordinate system to the ETRS 1989 geographic coordinate system. It's under geographic coordinate systems, Europe. In ArcCatalog, refresh the folder by selecting it and hitting F5. Now try adding the shapefile to a new ArcMap with your administrative boundaries. Melita

‎06-03-2013

Hi, The adscita mannii shapefile is still in latitude-longitude. When you labeled it as CH1903 LV03 using Define Projection tool or the data's property page in ArcCatalog, you updated the metadata only, not the actual coordinate values. The software then thinks the latitude-longitude values are in CH1903 LV03 meters. When those coordinates are unprojected back to lat-lon, you get values near the equator (because that's where the actual origin of the projected coordinate system is). I tried assigning CH1903, CH1903+, and ETRS89 to the data. Even after setting a transformation to CH1903 when it's defined as ETRS89, there's one observation falling outside of the administrative region layer. You might want to email one of the contacts listed at GBIF, or GBIF itself and see if they can clarify what coordinate reference system is being used. Switzerland could be CH1903, CH1903+, CHTRF, ETRS89 (once it's available on GBIF), or even WGS84. Regards, Melita

‎05-30-2013

Hi Simon, No, the upper values are fine. The minimum values are what's important. When we set up the xy domain values, we use what we call the 'horizon' aka valid area of use for the coordinate reference system. That's often much larger than the actual area of...use/interest. For example, the area of use for GDA94 MGA 55 is a 6 degree wide zone between 144E and 150E and 44S and 12S (very roughly!). The minimum values for the horizon for transverse Mercator with those parameters extends to the south pole and 45 degrees west of 147E. Geodatabase storage uses approximately the minimum horizon values and then calculates the maximum values by using the minimum values, xy resolution value, and the max integer storage, 2e53 - 2 or 9007199254740990. Anyway, what's the actual feature class extents? And they might be messed up compared to the actual data in the feature class. I would also try rebuilding the spatial index. Melita

‎05-29-2013

Hi Katy, If you're using 10.1, we check the data extents against the transformation and GCS (source/target) extents. Maybe you're hitting that. Try projecting the data in ArcMap instead by including some layers that worked fine. Once the data's added, the data frame is set to the target coordinate system, and the transformation is set, right-click the layer and select data, export data. In the new dialog, toggle it to use the data frame's coordinate system. If it does look like you're hitting an area of use issue with the transformation, would you mind sending me the extents of the layers you're having problems with? I can double-check what we're doing, and possibly ask that the area of use for the transformation or the GCS be revised so this data would work correctly. mkennedy at esri dot com Melita

‎05-29-2013

Hello, There isn't much information available for that part of the world. EPSG (http://www.epsg.org - I'm on the subcommittee that maintains it) thinks that the transformation, Arc 1950 to WGS 1984 (3) is incorrect. That Burundi data was on Arc 1960 instead. There's another transformation, Arc 1960 to WGS 1984 (4). You might try defining your data as Arc 1960 with the projection information you have and use that transformation. None of the transformations that I know about in that area are very good. Cliff Mugnier in his Grids & Datums column on Burundi lists a GK zone for Burundi that has a scale factor of 1.0, not 0.9996, so that's something else to try. Melita

‎05-29-2013

While it won't have labels, you should be able to use the Create Fishnet tool to create a line or polygon feature class. Melita

‎05-24-2013

Hi Tom, Even with the "User_Defined" rasters not having a transformation to RGF93 set, if they are in WGS84, they shouldn't be 50m offset. The RGF_1993_To_WGS_1984_1 transformation that we have uses zeroes for the parameters. Is the User_Defined_LCC data the same as that in the first post which you said lined up fine with other data? What's behind the "User_defined" (it means Esri software doesn't quite understand what's there)? If you add it first to ArcMap, can you post what shows up in the data frame properties, coordinate system tab in the text box for the current coordinate system? Thanks, Melita

‎05-23-2013

Hi Tom, If they're showing up in the arctic, that's more than just a geographic/datum transformation issue. It sounds to more like we're misinterpreting the coordinate system. Can you post the full details from one of the French rasters? Coordinate system (projection and parameters), raster's extent (in the projected coordsys and in lat/lon if you have the latter), approximate area of coverage. Is the IGN data available publicly, or at least its metadata? Melita

‎05-20-2013

Hi, Well, they may be marking it as equidistant cylindrical because that's how you end up viewing it in a 2D display. That is, if the data is georeferenced in degrees, and the software just displays it, it's using a pseudo-equidistant cylindrical (aka Plate Carree) projection. I would define it with a geographic coordinate system and see if that works. Melita

‎05-20-2013

To convert between ED50 and WGS84 with data post-2001 use ED_1950_To_WGS_1984_23 aka EPSG:1612. How wide an area does it cover? You could use a UTM zone if the area of interest fits within that extent. Otherwise, possibly a conic projection, but you would have to use a custom one. Melita

My Ideas

Latest Contributions by MelitaKennedy

Re: New XY layer from Lat Long (DD) not plotting correctly

Re: cannot identify xy features on arcGIS online map

Re: raster calculator issues!

Re: Vertical Datum transformations

Re: Adding X - Y data: other layers dissapearing

Re: projecting to Swiss national grid

Re: projecting to Swiss national grid

Re: Crazy map extent on Oracle layer

Re: ED50 above 62N

Re: From Burundi to WGS84 issue...

Re: Drawing a graticle behind features

Re: Combining different coordinate systems

Re: Combining different coordinate systems

Re: Equidistant Cylindircal in decimal degrees?

Re: ED50 above 62N

Re: New XY layer from Lat Long (DD) not plotting c...

Re: EPSG release and ArcGIS Projection Engine

Re: EPSG release and ArcGIS Projection Engine

Re: The vertical transformations WGS_1984_To_EGM96

Re: The vertical transformations WGS_1984_To_EGM96

Coordinate Reference Systems

Alaska GIS Users