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Javad LS Single-point Localization Video
Posted by shelby-h-griggs-pls on February 13, 2018 at 6:18 pmJust viewed the new videos by Shawn Billings, that one point localization is very sweet, not just for LDP’s but for using a current epoch RTN to get to an old epoch on an existing project (you just want to typically shift the XY while keeping the same grid bearings), way simpler than any other brand that I am aware of, in fact I don’t even know if there is an easy way to shift a broadcast RTN to existing control in most other brands. I don’t own Javad, have used Leica since 1994, BUT other brands should probably take notice of what Javad is doing with their on board firmware! If other brands can easily do what Shawn shows in the Single-point Localization I would be interested in hearing about that. I should say, this feat can be done with Leica gear, but not as slick as in the Javad LS. SHG
shawn-billings replied 6 years, 2 months ago 5 Members · 7 Replies- 7 Replies
The “pages” thing is great too.
You can set page 0 to spc, ar south.
Page 1 to spc ar north
Page 2 to any localize.
Page 3 to another localize.
And, inverse between ANY points, from any page, and it will display the answer, in whatever page is current.
N
I just used the multiple point localization to connect my gps work on state plane, points from an existing survey map on another coord system and our new instrument traverse in another system. They are all still in their original coordinate systems on the original “pages”, but all show up together on screen and I can stake out to map points using gps. Sweet.
Thank you for the kind words, Shelby. It truly means a lot. We have some very talented software engineers and geodesists who work very hard to make this software work. They are extremely open to recommendations from users which has enabled us to make the software more user driven.
Regarding epochs, I wrote this short white paper three years ago.
http://www.javad.com/jgnss/javad/news/pr20150312.html
Our interface in localization has changed just a little since then, but the features have remained unchanged since then. The paper explains how I used localization to do exactly what you are describing by determining an offset from one epoch to another. In my city we have a monumented network of about 30 control points that were established from a very good static network tied to the HARN. For quite some time we knew that the offset from CORS96(Epoch 2002) and NAD83, 2011 (Epoch 2010) to HARN(1993 Adjustment) were different by several centimeters in our area and that it was not well modeled. I tied into the 5 primary control points, used the localization routine to perform QA/QC analysis and calculate the transformation. Very similar to the single point, but strengthened somewhat by the addition of more points. The result was that I could use this localization to transform positions based on HARN to NAD83, 2011 (Epoch 2010), which is what OPUS provides, and from 2011 back to HARN. It’s a slick tool for sure.
- Posted by: Shelby H. Griggs PLS
Just viewed the new videos by Shawn Billings, that one point localization is very sweet, not just for LDP’s but for using a current epoch RTN to get to an old epoch on an existing project (you just want to typically shift the XY while keeping the same grid bearings), way simpler than any other brand that I am aware of, in fact I don’t even know if there is an easy way to shift a broadcast RTN to existing control in most other brands. I don’t own Javad, have used Leica since 1994, BUT other brands should probably take notice of what Javad is doing with their on board firmware! If other brands can easily do what Shawn shows in the Single-point Localization I would be interested in hearing about that. I should say, this feat can be done with Leica gear, but not as slick as in the Javad LS. SHG
Trimble has a shift option, I’ve never tried to do something like that in the field, however I do believe it’s possible in the controller, I may be wrong about that. It’s very easy in the office computer where I will usually do anything like; calibration or shifting. I prefer to work with static numbers if a calibration or shift is needed, I assume that isn’t so easy with an RTN. Normally, if I have site control I will use it as given and check between points assuming it’s GPS/SPC/UTM type of control.
Javad also has a Shift routine. I have no idea how it compares to Trimble’s. In J-Field (Javad’s field software), Shift is used to make a minute translation to match a known coordinate on a point. The most common application would be starting the base on a random point using an autonomous position (i.e. “Here” position), then recovering a point with a known geodetic position, and translating to this position. We actually have a couple of options to do this. Shift does a quick translation using a single point, while M-Local does the same thing using an unlimited number of points. Shift isn’t the same thing as a localization, per se, in J-Field.
Here’s a video that describes the Shift routine:
the shift is simply a +- number applied to the northings and eastings, it appears in the set-up routines. Of course the trick is to figure out what that number is. Then find out if there needs to be a rotation, elevation shift, scale factor to apply also. That is why calibration is popular.
If the coordinate system is the same there should be no rotation or scale factor to apply. The shift is used to buck in, either from autonomous to known of from one known epoch to another. Localization (or Calibration for Trimble users) should be used for determining differences between two different coordinate systems, most commonly associating an assumed system to a geodetic system.
Having said that, there is the possibility of biases creeping in when the coordinate system is the same in the RTK controller and in the published control. This could result in rotations due to measurement errors, particularly traversing.
We encourage users to apply Shift or M-Local to make small adjustments (a few meters at most) and use localization for any large translations that may also include rotation and scale.
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