Latest Contributions by FrancesBiles

‎07-28-2017

Thanks for replying Joshua. I am part of the Administrators group on my PC. What is the default location supposed to be?!

‎07-27-2017

I just installed ArcGIS Pro 2.0 and now want to install the "ArcGIS Pro Coordinate Systems Data" file. When installing the Coordinate Systems Data the default destination folder is C:\Users\username\Documents\ArcGIS Pro 2.0. However, this doesn't seem like a good location if multiple users might use the same computer....so, I have 3 questions: What is the recommended alternative location that would be accessible to all users? If the Coordinate Systems Data is not installed in the default Users folder, are there any extra steps required to point ArcGIS Pro to the alternate Coordinate Systems Data location? Same problem and questions for installing "ArcGIS Data interop Ext for Pro", "ArcGISProHelp_20", etc.

‎01-13-2016

Ok, thanks everyone. I believe I get it now! To summarize the responses and what I've read: 1) The first part of the transform, WGS_1984_(ITRF00)_To_NAD_1983, is converting from NAD83(CORS96) to ITRF00. ESRI considers ITRF00 identical to WGS84. WGS84 in this case means WGS84(G1150). WGS84(G1150) and ITRF00 are essentially identical (< 10cm difference). However, b/c my points are in NAD83(1986) instead of CORS96, about a 1.4 meter error is introduced. 2) The 2nd part of the transform, ITRF_2000_To_WGS_1984, is a zero transformation (a.k.a., "bookkeeping" transformation). So, no transform is being applied, but this step basically performs the job of a "define projection" to ITRF00. If I haven't mischaracterized anything I would mark this as answered. But everyone contributed to the answer - I don't think I'm able to "correct answer" everyone.

‎01-12-2016

Thank you Melita. I’m still a bit confused. To be specific, you are saying that the transformation method WGS_1984_(ITRF00)_To_NAD_1983 + ITRF_2000_To_WGS_1984 is doing a conversion from NAD83 (CORS96) to WGS84 only (which WGS84? G1150?), correct? However, the 7 parameter values used in the ESRI transformation match the values on the NGS website for converting between NAD83(CORS96) and ITRF00. Based on this I would think the ESRI transformation WGS_1984_(ITRF00)_To_NAD_1983 + ITRF_2000_To_WGS_1984 is converting between NAD83 (CORS96) and ITRF00, not NAD83 (CORS96) and WGS84(Gxxxx). Am I not interpreting this correctly? Any clarification is appreciated!

‎01-11-2016

...I also meant to add that the NAD83 page on the Confluence site has a great spreadsheet resource of datum conversions for ITRF00, WGS84, and NAD83. Thought I would post the link in case other found it useful.

‎01-11-2016

Hi Dan - Thank you for your response. I had tried the Confluence Mobile link you posted before but the page was blank. I was using IE, so just tried another browser and a page for "height aiding results" opened, which didn't look related to my question. Was your response "some minor shifts" in answer to my last question? Can you provide more details as to what the + ITRF_2000_To_WGS_1984 is doing in the WGS_1984_(ITRF00)_To_NAD_1983 + ITRF_2000_To_WGS_1984 transformation? I am converting from NAD83 to ITRF00. The ESRI geographic_transformations pdf shows the 7 parameter values used in the ITRF00_To_NAD83 part of the transformation, so I get that. But why is the "+ ITRF_2000_To_WGS84" part needed? What is it doing?

‎01-11-2016

Thank you everyone for the useful information. First an FYI, and then a question. Regarding the NAD83 version used for the WGS_1984_(ITRF00)_To_NAD_1983 transformation, I was able to find the answer from clues given by Neil and Melita. As Neil pointed out, the 7 parameter values are the same for all four ITRF00 to NAD83(1986), CORS96, 2011, and HARN transformations. I wondered which version of NAD83 these parameters are associated with. According to this NGS CORS page, the 7 parameters are specifically for ITRF00-to-NAD83 (CORS96). Q1) I'm not sure what the + ITRF_2000_To_WGS_1984 is indicating in the WGS_1984_(ITRF00)_To_NAD_1983 + ITRF_2000_To_WGS_1984 composite transformation. Why is this needed/what is it doing? Could someone please explain? -Frances

‎01-07-2016

I have some points in NAD83 (1986). In fact, A LOT of our GIS data is in NAD83 (1986). I am using Desktop ArcMap v 10.2.2.3552. I want to transform the points to ITRF00. If I choose: WGS_1984_(ITRF00)_To_NAD_1983 + ITRF_2000_To_WGS_1984 for the geographic transformation method, which flavor of NAD83 is being assumed? Everything I found suggests that NAD83 (CORS96) is being assumed. If that is the case, how does one transform between NAD83 (1986) to ITRF00? To ITRF08? (Or the most current version of WGS84?). The GIS data covers southeast Alaska. From what I have read, it looks like depending on what version of ArcMap one is using, the name "NAD83" could refer to completely different versions of NAD83. For example, in earlier versions of ArcMap, the transformation NAD_1983_To_WGS_1984_5 assumed that coordinates were in NAD83 (1986), but in current versions of ArcMap (10.x) NAD_1983_To_WGS_1984_5 assumes that coordinates are in NAD83 (CORS96). Is that correct? If so it would be VERY HELPFUL if datum names/labels always had their "version" attached. Does WGS84 in that transformation refer to the original WGS84 or WGS84(G1674), or? Is there a comprehensive "cheat sheet" that crosswalks ArcMap versions with the datum versions assumed for all datum and geographic transformation names that involve NAD83, WGS84, ITRF reference frames?

‎11-20-2014

Hello - I have a large (equivalent to size of Ireland) line feature class (fc) depicting a shoreline, which I am editing. The shoreline is in Alaska State Plane Zone 1 (meters), NAD83. The NAD83 realization is closest to NAD83(1986) or NAD83(CORS96). The shoreline is in an ArcMap document. The dataframe is set to Alaska State Plane Zone 1 NAD83 [EPSG26931]. I am using ArcMap v. 10.1 on Windows 7. I have two DigitalGlobe (DG) map services in the ArcMap document: 1) DigitalGlobe Web Map Service:Imagery, which is served in WGS84 [EPSG: 4326], and comes with an option to alternatively receive the image in WGS84 Web Mercator (auxiliary sphere) [EPSG: 3857]. 2) DigitalGlobe:ImageryTileService, which is served in WGS84 World Mercator [EPSG: 3395] I have no idea which realization of WGS84 is represented in these orthos. I would like to be able to use the DG ortho-imagery for digitizing new shoreline information and to update existing lines in the NAD83 shoreline fc. The problem is getting the 3 data sources to line up. For the dataframe properties I have specified the WGS_1984_(ITRF00)_To_NAD_1983 transformation. --I have some lines in the NAD83 shoreline digitized from in-house orthophotos that are also in State Plane AK Zone 1, NAD83. These features are about 8 meters off from the DG Imagery and 10 meters off from the DG TileService. However this could be explained by spatial inaccuracies from the orthorectification. --The DG Imagery and DG TileService orthos are about 12 meters off from each other. It seems I should be able to get these 2 sources to align with each other. The Questions: 1) Is there a transformation to align two images in WGS84 [EPSG 4326] & WGS84 World Mercator [EPSG: 3395]? 2) Can I align EPSG 4326 & 3395 with NAD83? Many thanks to anyone who can help.

‎11-08-2012

Thank you for the reply Carrie. I do not want to use a mosaic dataset because I need to create a layer to use in regional models and analyses and to share with others that may or may not be using ESRI tools. Also, as mentioned above, filling "no data" areas was not an issue. However, I did end up using focal statistics to smooth out the seam (so marked this question as answered) using the following syntax in Map Algebra: Con(~IsNull("SeamMask"), FocalStatistics("DEM", NbrRectangle(5, 5, "CELL"), "MEAN"), "DEM") Where SeamMask is a 200 meter wide raster that overlaps the seam where the DEMs adjoin. The results aren't fantastic, but it does help ease the transition between the DEMs a little.

‎11-02-2012

Hello, I have three exactly adjacent DEMs I am trying to mosaick together. There are no overlapping or NoData areas between the DEMs. The DEMs are in the same coordinate system, have the same vertical units, same cell size (50 meters), and are snapped to the same grid alignment. The DEMs are all terrain models (not surface models) and are stored as ESRI GRIDs. One of the DEMs is from the U.S. (NGVD29), and two are from Canada (CGVD28). The slight difference in vertical datums and source agencies contributes to variability in the elevation values between the data sets and creates a distinct "seam" where the DEMs are joined. What is the best way to smooth the seam where the DEMs are mosaicked/merged? I have created some polygon feature classes of varying widths that overlap the seam area with the idea of using one as a mask for applying some kind of smoothing function. Am I on the right track? Specifically: 1) Is there an efficient way to output the whole, merged DEM with the seam area smoothed? and 2) What are the best functions and options to be using for smoothing continuous elevation data (e.g., focal mean? neighborhood shape and size?). I have found several answers addressing smoothing overlapping areas between DEMs/rasters and how to fill missing data areas, but have not found anything addressing this issue. I would be grateful for any advice or pointers to other links on this topic. Running ArcGIS 10.0 with an ArcInfo license.

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Date Last Visited	‎11-11-2020 02:23 AM

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Latest Contributions by FrancesBiles

Re: Alternate destination folder for ArcGIS Pro Coordinate Systems Data and other ArcGIS pro extensions

Alternate destination folder for ArcGIS Pro Coordinate Systems Data and other ArcGIS pro extensions

Re: Which version of NAD83 is assumed in geographic transformation?

Re: Which version of NAD83 is assumed in geographic transformation?

Re: Which version of NAD83 is assumed in geographic transformation?

Re: Which version of NAD83 is assumed in geographic transformation?

Re: Which version of NAD83 is assumed in geographic transformation?

Which version of NAD83 is assumed in geographic transformation?

NAD83, Web Mercator, and World Mercator - how to align these projections in ArcMap?

Re: Smoothing seam between adjacent DEMs

Smoothing seam between adjacent DEMs

Re: Smoothing seam between adjacent DEMs

Alternate destination folder for ArcGIS Pro Coordi...

Which version of NAD83 is assumed in geographic tr...

Alaska GIS Users