View Full Version : Basis of Bearings State Plane Coordinates System
08-04-2004, 08:50 AM
Section 8764 as follows, taken from the State website:
"8764. The record of survey shall show the applicable provisions of
the following consistent with the purpose of the survey:
(a) All monuments found, set, reset, replaced, or removed,
describing their kind, size, and location, and giving other data
(b) Bearing or witness monuments, basis of bearings, bearing and length of lines, scale of map, and north arrow..."
We have a record of survey where the basis of bearings is the bearing between two HPGN NGS stations used for the control of the boundary survey. The deputy county surveyor insists that the basis must be a bearing shown on a map of record. As we read the text of the LSA that the basis must be shown but not restricted.
I faintly remember a board policy on this issue but could not find a copy.
Any help would be appreciated.
08-04-2004, 12:16 PM
I don't knowif this helps, but all Subidvision Maps in OC have to be based on two State Plane monuments, CORS, NGS, etc. This change was for GIS databases.
If your county requires the same for their subdivision maps then I would say they are contradicting themselves.
08-04-2004, 02:30 PM
I had a couple of conversions with Howard Brunner about this same topic. I did a Parcel Map for a certain city in Santa Clara County a couple of years ago. Unfortunately, the city does their own map checking on these. The project had started out with an ALTA/ACSM survey, which included aerial topography. I had set control with GPS tied to State Plane coordinates. I decided to do the PM on State Plane also. When I turned the map in for 1st check, I received a comment, from the map checker, that the bearings and distances did not match record mapping. Also, the map needed to be based on a record map. I explained to him that the map is based on the California Coordinate System of 1983, Zone 3, that this is a sufficient bearing basis. The map also included 2 first order CSRS monuments, with coordinates, and the boundary tied to it.
The city map checker told me he had never seen anything like that before. I told him this is becoming more and more the normal procedure for mapping. He told me, “that’s not the way we do things around here”. I ended changing the map to get it approved by the city, but not before voicing my opinion, nicely, to the person. OK, not so nice, but the map recorded.
Getting back to Howard’s and my conversation… after I had told him this story, he indicate to me that I could have based my map on “moss growing on the side of a tree as north”, for a basis of bearing. That the way I had the basis was acceptable.
It may be worth a call to Howard to get clarification. There seems to be a lot of people, with no survey knowledge, who still wield power over what we can and cannot do, even if State law says we can do it in a certain way.
OK , rant over.
Good Luck with your project.
08-04-2004, 03:04 PM
This No. Central Valley County has a private GIS in some unknown system.
We will ask the deputy county surveyor to add a note regarding his disagreement with our basis of bearing.
Thanks for the input.
Dave Karoly, PLS
08-04-2004, 03:25 PM
Haven't these checkers ever seen a map with a Basis of Bearings being a solar observation? That's not based on a map of record.
08-04-2004, 04:12 PM
I don't know if you'll find an old Board policy on this specifically. It's a little amazing they won't accept that basis, unless we're only getting part of the story here. Try to get a little higher in the agency and speak with an experienced LS. They need to be able to deal with this from here forward, because it's a totally valid basis. Ideally, you should be on the basis the deed is written on (if you're retracing a deed), which could be many sources other than a recorded survey or map. But more and more surveys are based on state plane control, which is addressed in the Public Resources Code. I'd be more concerned those provisions are being complied with than saying you can't use it.
08-04-2004, 09:30 PM
When you think about it, a Basis of Bearings based on a previous surveyor's definition of the bearing between 2 pipes is completely arbitrary and only based on 2 points. A Basis of Bearings based on SPC is established from an almost infinite number of points because it is a mathematical relationship between the longitude and latitude for any point and the Public Resources Code statutory definition of the SPC Zone!
In other words, if I file my RS based on the arbitrary bearing between 2 pipes and one of the pipes disappears...y'all ain't got crap anymore! If I file my map based on SPC NAD83, Zone 6 from a GPS observations on Epoch 2002.0000 between 2 pipes , then y'all can set up anywhere on the parcel and come up with the same Basis of Bearings any old time at all!
Let's see...base it on two pipes that could get torn out or base it on a mathematical relationship of the latitude and longitude as defined by California Statutes...Can you say "DUUUHHHH!"?
Years ago, after I took his seminar on Solar Observations, I turned in an RS with a Solar Basis of Bearings. Jack Sands had to come to the counter to tell the counter weenie that a Solar BoB was perfectly legal, legitimate and acceptable.
You see, the more things change, the more the stay the same!
Howard! Adjust these folks!
Bob, I want to see a copy of the note put on your map. That's got to be good for a few laughs at a CLSA dinner meeting. Pity the poor bastard, though. Can you imagine him showing his face at a survey function after that?
08-05-2004, 07:21 AM
Ian, Solar B.O.B. usually supports Public Lands System surveys but presents an excellent rebuttle. Ditto Dave Karoly.
D. Ryan, When my boundary is surveyed using GPS then that is what I want to stay with throughout the project, avoiding any rotational error created by an arbitrary B.O.B.
08-05-2004, 09:26 AM
Bob and Ian. I wasn't suggesting using an "arbitrary" basis of bearings. Too many surveyors jump on any two record pipes and call it a basis of bearings without respect to the deed basis. Following in the footsteps and leaving some correct footsteps to follow requires some attempt at defining the original basis. There are valid reasons for using a state plane basis also, although I don't know the specifics of your current project. Using a state plane basis only and not correlating it to surrounding historical surveys wouldn't be any better (in fact worse) than picking two record pipes and wouldn't be sound boundary surveying. And I'm not suggesting that's what anyone is doing here, just sharing some thoughts that are surfacing. This subject is about retracement and perpetuation. Lastly, the long time rift between the checking community and the private surveying community isn't helped by comments like "counter weenie" and "poor bastard".
Berk Blake, PLS CA
08-05-2004, 04:15 PM
the County Engineers Association of California's Guide To The Preparation Of Records Of Survey. My copy comes from the County Surveyor's Office of the County of Santa Barbara and is dated January 1, 2000. It speaks to the requirements of a Basis.
08-06-2004, 08:17 AM
From a copy dated January 1, 2000;
" B. Surveyors Notes
1. Basis of Bearings. The bearings shown on the map should ("should" underlined on the guide) be defined in terms of one of the following:
a. (describes all of the records allowed)
b. A solar or stellar observation.
(discussion describes those observation on the lines of the survey)
Now from the text:
"If the astronomic observations were made on a line not appearing on the map, the note may be generalized to indicate that the bearings shown on the map are referenced to the true meridian as determined by observation of (Polaris).
In either case, the field notes of the sun or Polaris observation should be made available to the County Survey for his review.
c. The California Coordinate System. When this system is used, the map shall show the line or lines connecting the survey to the control stations used, showing the grid bearings between them, and the relationship between grid north and astronomic north (theta angle). Should coordinates be shown for points established on the map, the control scheme by means of which the coordinates were determined must also be shown on the map. Refer to Section 8813 of the Public Resources Code.
The form of the note should be substantially as follows: "The basis of bearings for this survey is the California Coordinate System (NAD 83) Zone 4 as determined locally between USC&GS stations BACHELOR and MARCH, shown herein as: N27° 32'15"E"
This reference is the strongest to make my case. Unfortunately when the local land surveyors were lobbying the public works department to encourage the map checking department to allow presenting our closure calculations and the use of this guide, the civil engineer in responsible charge had no idea how this guide would improve the map checking process.
Thanks for the help.
08-06-2004, 04:14 PM
Although that guide may have been based on a good idea; that is, standardize the checking procedures used by counties in metropolitan areas so surveyors have some idea of expectations from neighboring agencies (high population areas containing numerous closely situated counties), keep it mind it has no legal standing and is not applicable to many parts of the state. It should not be artificially elevated to a level it does not enjoy. But it does make the point that Bob's basis is fine.
08-16-2004, 08:50 AM
As a checker I ask questions in the forum because I need to know what you , the PLS's, are thinking. I need to understand what is "reasonable". When I first took this job, I couldn't believe what they wanted me to do. I had 4 years of field and ZERO map-checking experience and they expected me to check the work of people with vastly higher qualifications and experience! I'm still relatively new at it so I ask lots of questions and I try to be diplomatic about corrections. Every day I learn something new about surveying. I have had several PLS/RCE's call me and correct me on my interpretation of a body of law. The problem occurs when it is my supervisor, a PLS, that requests the correction. I have changed my mind more than once because someone took the time to educate me on a specific subject. I take what they say to heart. I am always asking the PLS’s around me if my interpretations are valid. Sometimes I’m right and sometimes I’m not. Remember that good checkers become great PLS’s. Once or twice when I’ve been told where to go…I don’t take it personally but I do go talk to ALL of my supervisors to make sure I didn’t do anything wrong. I can sympathize with many because once it’s submitted it’s off your desk and you just want to get paid for it. I realize that every time you get it back, you’re spending money that you will never be able to recover. I know that and therefore, I try not to “waist” your time. I am always going to school and attending seminars so that I can do my job fast and more accurately. I swore an oath of office prior to my appointing and I take great pride in knowing that I am following through with all of my duties including protecting the public.
Oh yeah…Not all checkers are “created” equal. My inexperience can be a good thing. It means that there is hope.
08-17-2004, 08:14 PM
GregCVS; After 3 years as a CalTrans construction surveyor I too went directly into map/plan checking for a local City. You have the right ideas, keep it up.
Unfortunately many government employees feel that OJT is all the training they need and then only if directed by their superiors, why read the SMA and LS act when you can surf the net, and most take it personally if you don't agree with their requirements that are not based on the SMA or LS Act.
Fortunately, when I started map checking the SMA and LS Act were 5.5x8.5 and thin, now they are 8.5x11 and thick and in legalese, a sure cure for insomina.
The problems stated above, and many of my problems with agencies, is the agency employee is improperly trained. Many cities do not have a LS or CE/LS on staff, they are contracted, the City of Inglewood is a prime example, the counter people would not even give me the name or allow me to contact their LS or CE and they told my client that I should know all their map requirements and certificates.
I go to other Cities and ask for BM's and the person the engineering dept receptionist sends out doesn't know what a Bench Mark or centerline tie is or what it is for.
I know 10 years ago all mining claim surveys had to be based on solar observations.
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