Just did a 65 mile cors tie and here are the results

9 hrs of observations 0.22
1 hr 22 min to a diff. monument 0.19

Im still getting the hang of this but so far so good

My question is this,
In the processing, I had to use "unknown" for my antenna type at the cors station, I know what the antenna type/serial no. is for the site but I dont know where/how to get the information into solutions.

Any help would be appreciated

(where are you Phil)

Try the NGS GPS Antenna Calibration site for antenna dimensions.

(I just realized that may not be what you're after. I don't have Solutions running at the moment, so maybe someone else can point to the specific location of the antenna selections within the software.)
Modified By Jim Frame on 7/16/2003 at 3:57 PM

If you know the antenna type, select it in the observation properties window, accessed by double clicking on the observation bar in the time window, or in the workbook window under observations, right click on the station. Pick the antenna from the list or use the button the right with the 3 dots on it to enter the known parameters for the antenna.
See the Solutions manual.

0.22 Meters / feet?

Kevin

This is from a post in one of our early "O.R.G.I." discussions in December 2001:

I'm using the CORS data for "L1 Phase Center of the current GPS antenna" and the "NAD 83 POSITION (EPOCH 1997)"

example coordinate for comparison:

ARL5 Arlington, TX

Lat = 32 45 32.49931 N
Lon = 097 03 36.99084 W
ellipsoid height = 144.120 m

I'm setting up using geodetic/ellipsoid and meters. All constraint data is entered in above format. After processing I then change the settings to grid (my case Texas North Central Zone), ortho elevations/99 ellipsoid and U.S. feet

By using the coordinates of the L1 Phase Center, the antenna type or vertical offset do not come into play, as long as you use "Unknown" for the antenna type and be sure it's set in the software for "0" vertical offset. I have used this method (O.R.G.I.)for both Locus units as well as ProMark 2 units with what I think has been a successful run. Ashtech Solutions will account for the vertical Phase center offset in your unit (PM2) and if you use an HI value of "0" will solve to your ARP (antenna reference point).

My nearest CORS is 65 miles away, so in order to make anything of value come out of my L1 only ties to CORS, the O.R.G.I. stuff developed. Until NGS completes their development of an "OPUS" type system for L1, if they decide to continue, we are more or less on our own to make do with what we have.

j.d.

Open Ashtech Solutions 2.6. Click on Help. Click on Help Topics then on the Index tab.

Type

antenna

From the list, under antenna type, click on create and then click display.

Jim Frame provided the link to the most official source of antenna calibration information I know about. Mike Morrison is a very diligent guy who really wants to provide accurate information about antennas. On that web page you will find a pdf you can download (near the bottom right corner) that tells you what they do and how to read the antenna calibration information.

Alternatively, JD's idea works just fine. If your receivers are L1 only you can use the coordinates for the L1 phase center and a vertical antenna height of zero.

On the CORS web page there is a power point file that Neil Weston did that illustrates this business about the ARP quite well.