California Surveyors Forums

I am working on a Sub Map here in San Diego. San Diego Maps need to be tied to 1st order NAD 83 Control. In researching existing 1st order control, I found that there was nothing nearby.

Since my understanding of San Diego's policy is that the County Surveyor will either set you control within 0.5 miles from your site or waive the requirements, I sent the County an email. The response was to use the San Diego County Real Time Network and that because of this network, the County no longer sets monuments or waives the requirements.

I have two questions:

1. Is there anyone that can help me figure out the SDCRTN? I did some preliminary research and just got a headache. I currently only have experience using a base and a rover although my machine (Spectra SP80) is capable of the fancy modem stuff. I have no idea where to start!

2. What if the surveyor making the map doesn't have fancy GPS? Should he be required to contract out GPS services in lieu of traversing to monuments within the allotted 0.5 miles from the site?

I have a few questions that you may not be able to answer, but then again, maybe you can.

1. Is this 'tie in' requirement supported by the subdivision map act of other state law?

2. Is this 'tie in' requirement supported by an ordinance that the County of San Diego lawfully adopted?

3. Is this 'tie in' requirement the personal preference of a few who work for the County of San Diego and not supported by either 1 or 2?

I would really like to know an answer to this.

It is a County Ordinance adopted in the early 90s

See attached. It is a clip from the County document referencing the Basis of Bearings statement.

Whether or not an RTN network qualifies as a tie to 1st order control is another matter as well.

Section 8816. (Amended by Stats. 1986, Ch. 611, Sec. 15.)
Cal. Pub. Res. Code §8816.

The use of the State Plane Coordinates by any person, corporation, or governmental agency engaged in land surveying or mapping is optional.

I would attempt to use an OPUS solution that referenced two or more of the San Diego RTN stations for corrections. If the San Diego CORS/CGPS are used by OPUS then your resultant coordinates would then be tied to their network. You should be able to process a static session yourself if their stations are not shared with OPUS. Good luck!

I think OPUS would give you: NAD83 (2011) (EPOCH:2010.0000) ... SDCRTN is in: NAD83 (NSRS2007) 2011.00 Epoch

Also look at PRC 8813.3 and 8815.5 if using/showing CCS83 coordinates.

Rich