- #Trimble survey controller horizontal control plus#
- #Trimble survey controller horizontal control series#
However, depending on the VRS network you are using, you may need to do some sort of calibration to tighten up your results. In some instances, scenarios A and C could apply here. I am going to do a VRS survey, do I need to calibrate? This can be done through various methods of having known local coordinates, or computing coordinates to use in the calibration. More details on this recommendation are below.
![trimble survey controller horizontal control trimble survey controller horizontal control](https://sitechrockymtn.com/wp-content/uploads/2019/04/Choose-Trimble.jpg)
It is recommended to have a minimum of three horizontal control points and four vertical control points to get into the local coordinate system. The base will need to be started with a “Here Key” to establish a WGS84 coordinate to start the base receiver from. A project needs to be created using No Projection/No Datum. There are no pre-loaded local coordinate systems in the controller’s software. An example of this would be a 10,000/10,000 system.Ī calibration is recommended in this case. The survey needs to be in a local coordinate system.
![trimble survey controller horizontal control trimble survey controller horizontal control](http://dhtechtools.com/wp-content/uploads/2015/12/s-l1600-466-1080x1440.jpg)
Using a geoid model is recommended under this scenario. The rotation and the scaling are determined by the selected coordinate system. A simple single point calibration can then be use to “translate” your survey from the measured GNSS position, to the known NEE coordinate of the control point. You are able to start your base survey using the “Here Key” which will give you autonomous NEE coordinates in the coordinate system that you defined. You can select your desired coordinate system in your project setup, and choose an ideal spot on or near your project to set up your base receiver. I have known control I can check into, but I do not have a good, known point to set my base on.Ī calibration is a good option here. I want to work in a pre-defined coordinate system.
#Trimble survey controller horizontal control plus#
You would want to select the coordinate system, plus the geoid model when in this field scenario. Here no calibration is needed, assuming field checks work out. I want to work in a pre-defined coordinate system, and I have known control to set my base station on, and known control to check into. These scenarios certainly do not reflect all instances in the field, but should give you a good idea of what to look for. However, I can provide you four common scenarios, along with suggestions on what could be done. Every project and scenario is different, so the answer will ultimately depend on the situation. There really isn’t a yes or no answer to this question. If you use a geoid model, an inclined correction plane is created based on the residuals between the geoid defined by the orthometric heights of the local control and the applied geoid model. If you do not have a geoid model, a simple vertical shift as a single point can be applied, or and inclined plane can be computed using the orthometric heights of the local control. The vertical adjustment can be done with or without a geoid model. The parameters resulting from this are a rotation, translation, and a scale of the GNSS coordinates. The horizontal adjustment is a least squares best fit to make the GNSS derived grid coordinates fit, as closely as possible, to the local control grid coordinates. Essentially, a GNSS site calibration establishes the relationship between WGS84 latitude, longitude, and ellipsoidal height, with the needed local northing, easting, and elevation.Ī site calibration typically consists of a horizontal and a vertical adjustment.
![trimble survey controller horizontal control trimble survey controller horizontal control](https://img.yumpu.com/18215623/1/500x640/support-faq-trimble-survey-controller-software-v1105.jpg)
This can be accomplished by working in a pre-defined coordinate system with known control, or by performing a GNSS site calibration. To benefit from the increased accuracy of modern RTK GNSS surveying, the WGS84 coordinates need to be translated into local grid coordinates. A GNSS receiver measures WGS84 latitude, longitude, and ellipsoidal height coordinates to determine its location, however, surveyors typically use a local grid coordinate system.
#Trimble survey controller horizontal control series#
Here we will address four of the more common questions to hopefully provide you some basic knowledge about what calibrations are and what they do.ġ.) What is a GNSS site calibration, and how does it work?Ī site calibration is a series of mathematical computations that transform WGS84 coordinates into local grid coordinates. Every year we get a lot of questions about GNSS site calibrations. Spring is finally here and the 2013 surveying and construction season is about to take off.