Shawn Billings, post: 455807, member: 6521 wrote: The base was started from an autonomous position. I processed the base to CORS using DPOS. This caused the base position to move in my local system. I then rectified it by opening localization again and the parameters were recalculated using the new geodetic positions of the points shot from the base.
No not really. You should re-watch this part. I zeroed the inclined plane. This effectively translated vertically using the average difference of all points held in vertical. Since there was no additional tilt, the vertical datum is based on the Geoid used for the surveyed points (in this case Geoid12B). The units for the tilt in this application are degrees, minutes, seconds. 0 is zero seconds. Inclined planes are the reason you are typically encouraged to stay "in the box". If you aren't tilting the plane though, you're on the Geoid and you are free to work beyond the limits of the control.
Nothing helps when the base data is bad. You'll notice, the video says one of the keys to success is reliable coordinates.
Do you localize the Base to your OPUS or DPOS position? I just correct the Base autonomous position the the more accurate OPUS position. I'm not familiar with DPOS. Seems easier and there's nothing special about the autonomous coordinate.
No I don't use localize to refine the base position. I only use localization to match a local system (with unknown relationship to the Earth) to a geodetic coordinate system. DPOS is Javad's post processing service. Similar to OPUS, it processes the base to the 5 CORS. It also processes the base to rover points with raw data so that you have a comparison between RTK and the post processed vector.
The next Trimble Geospatial TBC Power Hour topic is site calibrations in TBC. If anyone is interested and needs the link let me know and I'll forward it.
Shawn Billings, post: 455807, member: 6521 wrote:
No not really. You should re-watch this part. I zeroed the inclined plane. This effectively translated vertically using the average difference of all points held in vertical. Since there was no additional tilt, the vertical datum is based on the Geoid used for the surveyed points (in this case Geoid12B).
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Thanks Shawn, I saw that you zeroed the inclined plane, to me that meant the elevations would stay parallel with the ellipsoid, I wondered if doing that would apply the Geoid model to the points, glad to see it does. Are you holding the elevations of the control points of unknown projection and applying the Geoid to those elevations?
