So I ran static session for an elevation cert.and adjusted by logged data through opus. The opus results show datum as "REF FRAME: NAD_83(2011)(EPOCH:2010.0000" and I would be using spc new york central.
So to make a comparison I took a location on my static points with my network rover. The reference network also uses NAD83(2011). So as I look at the comparison data, the elevations match within reason but the network coords are about 3.5' off of my static coords. So as I am playing with my datum in Magnet field I change from nad83(2011) to NAD83_NO_TRANS and interesting enough there is a perfect match. So I am wondering if because the network base is already nad83(2011) it would be like doing a double transformation that is throwing off the coords.
The personal consensus would be of course use the NAD83 no transformation but I would like to know why for when I may use the coordinates with a base and rover. I would think that probably I would have to switch back to NAD83(2011) on Magnet.
I was thinking about calling topcon to get some input but I thought I would see if anyone else had any thoughts or experience with this.
You understand correctly. If your base is broadcasting NAD83 then you don't need any transformation. You would only need the transformation if the base is broadcasting ITRF coordinates. The deeper question is 'what transformation is being applied?' 14 parameter? If so, it's not erong, but it is also not the same as HTDP.
BIDDLECW, post: 321913, member: 9943 wrote: So I ran static session for an elevation cert.and adjusted by logged data through opus. The opus results show datum as "REF FRAME: NAD_83(2011)(EPOCH:2010.0000" and I would be using spc new york central.
So to make a comparison I took a location on my static points with my network rover. The reference network also uses NAD83(2011). So as I look at the comparison data, the elevations match within reason but the network coords are about 3.5' off of my static coords. So as I am playing with my datum in Magnet field I change from nad83(2011) to NAD83_NO_TRANS and interesting enough there is a perfect match. So I am wondering if because the network base is already nad83(2011) it would be like doing a double transformation that is throwing off the coords.
The personal consensus would be of course use the NAD83 no transformation but I would like to know why for when I may use the coordinates with a base and rover. I would think that probably I would have to switch back to NAD83(2011) on Magnet.
I was thinking about calling topcon to get some input but I thought I would see if anyone else had any thoughts or experience with this.
BIDDLECW,
If you choose NAD83(2011) in Magnet using NYSNET RTN, then you will create an error from a double transformation.
NYSNET has already adjusted for NAD83(2011), therefore no need to transform a second time.
You must use the NAD83-NO_TRANS with NYSNET RTN on MAGNET.
Lee Green
