https://community.esri.com/t5/arcgis-survey123-questions/cm-precision-with-smartphone-gps-and-rtk/m-p/1073663#M35615 <P>I’m trying to get cm accuracy with Survey123 on smartphone GPS, whilst keeping hardware costs down for our volunteer team.</P><P>In theory it should be possible for the onboard GPS to accept corrections from a RTK service provider, without having one’s own GNSS RTK hardware.</P><P>I understand this could be achieved by a smartphone app overwriting the GPS location with a RTK-corrected location.&nbsp;Survey123 would then see the more accurate location.</P><P>If that’s correct, then it’s very strange that no such app seems to exist! I’ve researched this diligently (and I’m a Solution Architect).</P><P>Is there a software way, please?</P><P>Thanks, Adrian, UK.&nbsp;</P> Tue, 29 Jun 2021 13:58:45 GMT Adrian_S 2021-06-29T13:58:45Z https://community.esri.com/t5/arcgis-survey123-questions/cm-precision-with-smartphone-gps-and-rtk/m-p/1073663#M35615 <P>I’m trying to get cm accuracy with Survey123 on smartphone GPS, whilst keeping hardware costs down for our volunteer team.</P><P>In theory it should be possible for the onboard GPS to accept corrections from a RTK service provider, without having one’s own GNSS RTK hardware.</P><P>I understand this could be achieved by a smartphone app overwriting the GPS location with a RTK-corrected location.&nbsp;Survey123 would then see the more accurate location.</P><P>If that’s correct, then it’s very strange that no such app seems to exist! I’ve researched this diligently (and I’m a Solution Architect).</P><P>Is there a software way, please?</P><P>Thanks, Adrian, UK.&nbsp;</P> Tue, 29 Jun 2021 13:58:45 GMT https://community.esri.com/t5/arcgis-survey123-questions/cm-precision-with-smartphone-gps-and-rtk/m-p/1073663#M35615 Adrian_S 2021-06-29T13:58:45Z https://community.esri.com/t5/arcgis-survey123-questions/cm-precision-with-smartphone-gps-and-rtk/m-p/1073716#M35616 <P>Hi Adrian. To my knowledge, it is not possible to use RTK corrections against the location data provided by the built-in GPS in a smartphone. You need to use an external GNSS receiver specifically designed to work with RTK. More info about support for external GNSS receivers in Survey123:</P><UL><LI><A href="https://community.esri.com/t5/arcgis-survey123-blog/direct-gnss-external-receiver-support-in-survey123-3-3/ba-p/896593" target="_blank">https://community.esri.com/t5/arcgis-survey123-blog/direct-gnss-external-receiver-support-in-survey123-3-3/ba-p/896593</A></LI></UL> Tue, 29 Jun 2021 15:06:16 GMT https://community.esri.com/t5/arcgis-survey123-questions/cm-precision-with-smartphone-gps-and-rtk/m-p/1073716#M35616 IsmaelChivite 2021-06-29T15:06:16Z