Hi Anybody from "CSRC: California Spatial Reference Center", or a friend of a friend? It would be interesting if they register their CRSs in EPSG.
If anyone knows who can I contact there, it would be appreciated. Best regards, Javier. On Fri, 26 Jan 2024 at 20:12, Brian Shaw <brian.s...@noaa.gov> wrote: > All > > Yes we are aware of this California Datum and it was developed by the > California > Spatial Reference Center <http://sopac-csrc.ucsd.edu/index.php/csrc/> ( > http://sopac-csrc.ucsd.edu/index.php/csrc/) at the request of CALTRANS. > As suggested with California being on two tectonic plates with earthquakes > that cause large displacements they needed to have a more updated datum > than the time frame that NGS develops them. I cannot specifically recall > the earthquake that initiated this datum but I think it may have been one > near Napa. In my presentations I highlight the challenges California has > due to earthquakes (China Lake in 2019 cause 6-10 feet of horizontal shift) > and from subsidence (San Joaquin Valley USGS study showed up to 2 feet of > subsidence in 16 months). If interested here is a presentation I provided > that has some of this information ( > https://geodesy.noaa.gov/web/science_edu/presentations_library/files/shaw_nsrs_mod_nsgic_20230928.pptx > ) > > Since Esri is based in California I suspect that is why they implemented > it but this is not an NGS developed datum so I believe CSRC or CALTRANS > would have to submit it to EPSG. > > I hope this helps > Brian > > On 1/26/2024 11:02 AM, Even Rouault via PROJ wrote: > > Hi, > > interesting... It is known by ESRI as > https://spatialreference.org/ref/esri/104024/ but AFAICS, there isn't any > transformation registered in their database between this datum and other > North American datums. > > There's a slide deck talking about it, where HTDP is mentionned ( > https://www.ngs.noaa.gov/TOOLS/Htdp/Htdp.html) : > https://geodesy.noaa.gov/geospatial-summit/year-2019/files/martin-coordinates-moving.pptx > , but I've the feeling the message might be that Californians found HTDP to > not be faithful enough for their purpose. I dunno.. I guess our friends > from NGS could confirm or infirm. > > I guess the reason for a separate datum is that part of California is > anchored on a separate tectonic plate than the rest of N.A (or even the > parts on the N.A. plate are subject to high deformation). Presumably this > will be obsoleted by the NATRF2022 when it comes into life, and > interestingly I found in > https://casetext.com/statute/california-codes/california-public-resources-code/division-8-surveying-and-mapping/chapter-3-geodetic-datums-and-the-california-spatial-reference-network/section-8852-nad83-natrf2022-or-patrf2022 > that states "The official geodetic datum to which horizontal positions and > ellipsoid heights are referenced within the State of California shall be > NAD83, NATRF2022, or PATRF2022". Oh joy! > > Even > Le 26/01/2024 à 18:24, Javier Jimenez Shaw via PROJ a écrit : > > Hi > > I discovered today that there is a datum in California called "CSRS Epoch > 2017.50 (NAD83)" > http://geoweb99.ucsd.edu/index.php/epoch2017/ > http://sopac-csrc.ucsd.edu/ > > "CSRS Epoch 2017.50(NAD83) replaces the previous “CSRS Epoch 2011.00 > ITRF2005 NAD83(NSRS2007)” datum that included coordinates for 830 CSRN > stations." > > I have not seen it before, so I guess there is no CRS using it in EPSG. (I > do not find that datum in EPSG) > How can it be used with PROJ? > > (Is it normal that some states use their own datum in the US? It is not > enough with hundred of State Planes ;) > > Cheers, > Javier. > > PS. Be careful with the acronyms: > CRS: Coordinate Reference System > CSRC: California Spatial Reference Center > CSRS: California Spatial Reference System > NAD83(CSRS): Canadian Spatial Reference System > > So "NAD83(CSRS)" and "CSRS (NAD83)" are not the same. > > .___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... .... ._ .__ > > _______________________________________________ > PROJ mailing > listPROJ@lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/proj > > -- http://www.spatialys.com > My software is free, but my time generally not. > > > _______________________________________________ > PROJ mailing > listPROJ@lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/proj > > > -- > ************************************* > Brian Shaw > Rocky Mountain Regional Advisor (CO, MT, WY) > NOAA's National Geodetic Survey (NGS) > Cell Phone # 240-988-6363 > >
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