topic Drawing curves using the parcel editor toolbar in State & Local Government Questions

Drawing curves using the parcel editor toolbar

Anonymous User — Mon, 15 Apr 2013 17:38:16 GMT

Original User: danielchaboya

I'm trying to create a farily simple parcel but I can't seem to get the correct angle of the curves.
[ATTACH=CONFIG]23513[/ATTACH]

I'm starting at a control point (bearing and distance indicated by dashed line). After that I type the following on my next row in the Parcel Details window(Bearing 175-45-41, Radius 4.00, Chord 5.935).
[ATTACH=CONFIG]23517[/ATTACH]

As a result a get the following (i'm trying to recreate the parcel)...
[ATTACH=CONFIG]23519[/ATTACH]

Any thoughts as to what i'm doing wron? I'm new to parcel editing so I'm sure I'm missing some basic concepts here.

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Wed, 17 Apr 2013 15:46:20 GMT

Original User: ccorwin15

It looks like to me that your problem is that it is trying to create a tangent curve to your line to the control point...
From your picture, I can not tell if you have the bearing of the line above the curve or not, but if you do, type in the bearing and distance of the line above the curve first, then in the bearing field, type "*", enter the rest of the data and hit enter. This will create a tangent curve to the previous line. Then afterwards, enter in the information for the line going to (or from the control point) and connect it to the curve by changing the to or from point id. Does this make sense?

Re: Drawing curves using the parcel editor toolbar

BrianKlawinski — Wed, 17 Apr 2013 20:18:07 GMT

Curves are hard to do with the standard tool. I have a solution if you'd like to hear the details email salesinfo@tractbuilder.com.

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Thu, 18 Apr 2013 21:03:39 GMT

Original User: danielchaboya

It looks like to me that your problem is that it is trying to create a tangent curve to your line to the control point...
From your picture, I can not tell if you have the bearing of the line above the curve or not, but if you do, type in the bearing and distance of the line above the curve first, then in the bearing field, type "*", enter the rest of the data and hit enter. This will create a tangent curve to the previous line. Then afterwards, enter in the information for the line going to (or from the control point) and connect it to the curve by changing the to or from point id. Does this make sense?

Thanks for responding Chris. Yes, this does make sense and it works. Maybe you can help me out with another curve problem. From the image below, how would you go about drawing that curve. In this case I can not use a tangent line.

[ATTACH=CONFIG]23625[/ATTACH]

Cheers.

Re: Drawing curves using the parcel editor toolbar

TimHodson — Fri, 19 Apr 2013 04:53:43 GMT

Hi Daniel,

In the first case you can also achieve what you need without using the tangency. In the second case it looks like the image that you attached is cutting off information for the radial line bearings to the east where the dashed lines extend? Are there bearings on those lines?

For your first case, I created a new Plan with the properties shown in the image below:
[ATTACH=CONFIG]23632[/ATTACH]

The settings under circular curves are the most relevant for your case.

I'm assuming your bearings are all South Azimuth (0 degrees south)? I used south azimuth to match your image's orientation, and assumed north is straight up the page. South Azimuth is rare, so please only use this setting if you're truly working in South Azimuth.

After making this new plan, you can add a new parcel into that plan, and enter it as follows:
[ATTACH=CONFIG]23633[/ATTACH]

There is also more information about entering circular arcs in this post: Dealing with missing traverse information in COGO

-Tim

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Fri, 19 Apr 2013 14:15:27 GMT

Original User: danielchaboya

Thanks for the suggestions, Tim. After trying your solution, it looks like I have to switch between North and South Azimuth. Trying you solution for the first curve (bottom right) works as you suggested. The second curve (bottom left) uses a North Azimuth. Is it common for there to be more than one azimuth on a legal plan?

Here is a more complete image for the second question...

[ATTACH=CONFIG]23657[/ATTACH]

Re: Drawing curves using the parcel editor toolbar

TimHodson — Fri, 19 Apr 2013 15:53:07 GMT

Within the US the only place I'm aware of that have plans that use South Azimuth is Hawaii. You would never see both North Azimuth and South Azimuth on the same plan, and so you'd definitely not be switching between the two while entering information on the same plan. However, there are also differing conventions on placement of the bearing in relation to the line, with respect to which way the line is running. For example, you'd ask yourself the question "Is the bearing annotated on this line oriented from point A to point B or is it going from point B to point A?" If you are at point B, and you want to get to point A, but the bearing shown on the plan is going the other way, then you need to add or subtract 180 degrees from the bearing to enter the value to run the line the correct way.

I see what you're referring to about the comparison between the first and second curves. There is an apparent inconsistency in the way the radial bearings are oriented. If your plats are in North Azimuth, then in the first image the radial lines are oriented from the center point of the curve, towards the curve's points, whereas on the second curve they are oriented away from the curve's points towards the center. When entering information for radial lines using parcel editor, the orientation is expected to always be towards the center point of the curve.

So, if changing plan settings to now use North Azimuth, it'd mean that the bearing on the first line entered, as annotated on the plan, is oriented away from the parcel and not towards the parcel, as I first thought, so that bearing would need to be reversed.

Setup and entry for case1, using north azimuth would be:
Setting the plan properties as follows:
[ATTACH=CONFIG]23662[/ATTACH]

Entry of the first 4 lines would be:
[ATTACH=CONFIG]23663[/ATTACH]

For the reversed bearing cases, if needed you can enter the value as shown on the line, and then use the Reverse Bearing command on the context menu:
[ATTACH=CONFIG]23664[/ATTACH]

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Fri, 19 Apr 2013 16:48:59 GMT

Original User: danielchaboya

Excellent information, Tim. I will give it a go and see if I can get this to work.

Re: Drawing curves using the parcel editor toolbar

ChrisCorwin — Mon, 22 Apr 2013 14:40:50 GMT

Tim is a wonderful resource! Its good to see him on the boards!
Just a quick and dirty way to fix your second image, (very dirty) is to COGO in all the non-curved lines and then digitally (snap to the POB) close the parcel. Then type in the radius. It is not the true measured bearing and distance for that line, but it gets the job done. I have had to do that for a few parcels.

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Mon, 22 Apr 2013 17:50:30 GMT

Original User: danielchaboya

For the line created by snapping to points, why would you not get a true length if you supply it with the radius and arc length? Is it do to the bearing?

Re: Drawing curves using the parcel editor toolbar

TimHodson — Tue, 23 Apr 2013 15:49:25 GMT

I've attached an image for the entry of the second case, using the same Plan settings as for the first case. Chris' suggestion is for instances where you do not have enough information for a circular arc's orientation. For example, in the second case, if there were no radial bearings to define the orientation of the curve, you would start at the south east corner, cogo in the first three straight lines, digitize in the last closing course as a straight line, and then edit the last course by entering in the radius. The downside of this is that you are not getting the benefit of closure, and ensuring that no mistakes were made in the entry of the prior courses. In some scenarios you may have no choice but if there is enough information, as shown in this data, then it's better to enter the complete curve information, and get the benefit of the QA from the misclose information:

[ATTACH=CONFIG]23726[/ATTACH]

-Tim

Re: Drawing curves using the parcel editor toolbar

Anonymous User — Tue, 23 Apr 2013 20:29:13 GMT

Original User: danielchaboya

Tim, you've been a huge help. Your solutions have worked and I'm finally starting to understand how parcel editing works in ArcGIS. Thanks again.

Daniel