Traverse Tool and COGO Question

[BrianAnisimov]

I have a several questions in regard to using the traverse tool to digitize an old parcel map. I would like an answer that is more in depth than, "See ESRI Traverse tutorial" since the page doesn't go over entering older parcel data like the one shown in the attached image.  

1.  How do I go about entering these angles more efficiently?  Since no direction is given, I have been drawing right angle lines and using the deflection tool.  This is really tedious since it requires me to convert from degrees, minutes and seconds to decimal degrees and subtract from 180 before finally entering the desired deflection angle.  I am new to using the traverse tool and surely there is a better method for entering these lines.  

2. How do I go about entering this curve with the given information?  I'm unclear what the Δ=111°-05'-40" represents here.  Is this a format for direction or is it just another way of writing the delta angle?  Trial and error has not yielded any curves that even remotely resemble the attached parcel information. 

I would really appreciate some help or direction toward useful resources.  

Thanks in advance

[jcarlson]

For the first point: entering deflections in the Traverse panel is simple. In the direction, instead of entering a full bearing, you can enter + or - followed by an angle, even in DMS.

+88-22-50

Keep in mind, this deflects off of the prolongation of the previous call, whereas these deflections are given as "lookback" angles, so you'll need adjust appropriately. You could enter -- in the direction field to get the 180 degree angle, then re-enter the field and deflect from there, though I've not actually tried that.

Second point: you got it, that's a delta angle. The Traverse panel should let you change the arc length column to a delta angle column so that you can directly enter the angle as it's written.

[BrianAnisimov · Accepted solution]

Hi Josh thanks for the answer.  I have a few follow up questions. 

1. How are you able to enter the angle in DMS format in the direction box of the Traverse pane?  When I type +88-22-50 into the direction box, it just reverts back to the last direction that I entered.  This only seems to work if the angle is in decimal degree format.  See image example 1 and example 2.    

2. When generating curves, how do you create them with the traverse tool when no directional measurement is given?  It seems very common for old maps to omit this information.  See example 3. 

[jcarlson · Accepted solution]

1. I forgot to mention, you need to go into your project's Units settings and change the angular units to DMS. It should then function as I described. 

2. How do I create them? With great difficulty! Sometimes a plat will have a curves table with the chord bearings if I'm lucky, but I still run into situations like that where there's no real bearing information. I hate making assumptions about plats, but sometimes I just have to assume that the curve is tangent to the previous segment.

Looking at your example, is CA "central angle?"

[BrianAnisimov]

Thanks for the help Josh.  You've been a big help.  I'm assuming that CA stands for central angle.