Latest Contributions by MelitaKennedy

Hi Calum,  When you added the xy data, you set the coordinate system to OSGB36? Or WGS 1984?  Ah, the longitude and latitude fields in the csv files are swapped. The -1 values should be labeled longitude and the 51 values are the latitude values.  If the OA data is really in British National Grid, you should set a transformation. Open data frame properties, coordinate system tab, transformations button. Melita ... View more

They probably needed a geographic transformation. Do you know if one was set? I would try re-doing them but making sure that a transformation is set. You could check this by adding the SA equal area conic PCS data to ArcMap, add the WGS84 data and set a transformation. You should get a warning message.The warning dialog has a button that links directly to the transformation dialog. If you don't get the warning after adding the WGS84 data, open data frame properties, select the Coordinate Systems tab and click the Transformations button. ... View more

The 14/15 parameter time-enabled transformation usually converts between two reference frames at a particular epoch date. That'll be round 1. To change epochs within a reference frame, we need the velocity model for the area and/or seismic event models. We're also working on that, but that may or may not get into the software in the initial install. Melita ... View more

UTM uses transverse Mercator which maintains angle/shape accuracy, not areas which would also be calculated at the planar surface, not topographic surface. I wouldn't expect the areas to be really off in zone 14 versus zone 15--since they're already "off". ... View more

Hi Chris,  We're working on it! It's currently working at the projection engine level. We need to make a new geoprocessing tool and support an "Epoch" parameter on a GCS.  Melita ... View more

Possibly--is the road very straight at that point? What could be happening is that the line should have a few more vertices in it. That is, the shape of the line should change with the reprojection, but isn't.  Melita ... View more

If you're interested, drop me an email (mkennedy at esri dot com) and I can send you a document that discusses working with local coordinate systems. Melita ... View more

Since you're interested in calculating areas, you could reproject everything to an equal area projection like Albers. There is a continental South American Albers. Another possibility would be the Brazil Polyconic. Depending on what version you're on, there are ways to calculate geodesic-based areas even if the data is in a different coordinate system.  Take a look at Add Geometry Attributes and Calculate Field help topics for information on calculating geodesic-based areas and lengths. If, for other reasons, you want to stick with UTM, probably use UTM 22S, as you seem to have data in zones 21-23. ... View more

Hi Jack, I won't be much help on the developer-side, but I wanted to ask about the coordinate system you're using. You mention local project coordinates as well as "non-earth". I'm used to seeing "non-earth" used in connection to MapInfo or Oracle (?). Am I correct?  As a long-shot, the data could also be extraterrestrial like on Mars or the Moon. That's not true, is it? Are there any ties to the earth? Sometimes it's possible to define a custom projected coordinate system for a local system if there is some information tying it to the earth OR control points exist in that system and a 'known' system like a UTM zone. And for someone who understands the programming side better, are you getting errors with the code you posted? Thank you, Melita ... View more

Very good point. Of course, the release after I take it out, our projections developer will decide to implement it, and I'll have to put it in again!  re: ArcView GIS's "world from space". We very, very rarely get rid of anything out of the projection engine. ... View more

Spatial oblique Mercator is only available in ArcInfo Workstation. So far it hasn't been ported to the projection engine, which would make it available in Desktop/Server/Pro/etc. levnagdimunov0‌  Unfortunately, we do not yet support the geostationary satellite view projection. It's actually been a few years since anyone asked for it or even the space oblique Mercator. Melita ... View more

Note that this functionality is new at Pro 2.0! ... View more

Just double-checking--you're good? ... View more

I hope the documents I sent you are helpful. What happens if you try this WKT? Make is a .prj file and browse to it to set the data frame or the data's coordinate system. Make sure it's a single line in the text file. PROJCS["NAD_1983_UTM_Zone_9N",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",23818.899],PARAMETER["False_Northing",-5922676.481],PARAMETER["Central_Meridian",-127.81305555556],PARAMETER["Scale_Factor",1.000125],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]] Melita ... View more

Did you try to redefine the coordinate system to UTM zone 9N using the Define Projection tool or the data's property page? That won't work as it just updates the metadata. You would need to use the Project Tool or georeference the data directly to UTM  zone 9N. If you include the information on how to convert it in AutoCAD here someone might be able to help. Also, if you email me (mkennedy at esri), I can send you two documents that discuss how to work with data in a local coordinate system. Melita ... View more