Question about Javad DPOS report

jcorax

Member
I am trying to figure out what DPOS is outputting. Specifically if I do not specify a "Report coordinate system" then the DPOS report outputs a local format for the bottom right set of coordinates. In my case these are headed "State Plane Coordinates" "SPC (NAD83(2011) /5005 Alaska zone 5 - 156-152° W)" and labeled from the left for "meters". This makes sense.

If I specify a "Report coordinate system" such as EPSG:4326 the output I get for the bottom right set of coordinates is confusing. The result shows up labeled as "State Plane Coordinates" "SPC (WGS 84)" and appears as degrees minutes seconds N and W. Except for the confusing State Plane Coordinates and SPC labels this would appear to be the WGS84 coordinates I am looking for. I don't believe there is an existing state plane system using WGS84.

If I try to check if this is indeed a WGS84 output by using third party tools to convert between SPC (NAD83(2011) /5005 and WGS84 then I don't get matching results.

What is DPOS giving me? Am I able to get WGS84 values? I do understand that IGS08 is very nearly equivalent to WGS84 however it seems that choosing the actual WGS84 rather than the very nearly equivalent would be best.

Would Justin documentation be helpful for understanding this issue? Any other resources?

Possibly I am missing a big assumption here? Any explanations/help would be appreciated. Thanks!

Files of the same point processed the two ways are attached: one with no "Report coordinate system" specified and the other with EPSG:4326 specified.
 

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Matt Johnson

Well-Known Member
5PLS
I believe it is displaying WGS84 coordinates because it didn't not recognize the SPC you entered.

@Alexey Razumovsky can you comment on the formatting that is needed to enter a custom Report coordinate system? It would be nice in the future if CSs can be selected from menu.
 

jcorax

Member
Hi Matt, your reply is much appreciated.

Inferring from your answer: Is the "Report Coordinate System" field meant only for manually entering the appropriate State Plane Coordinate System (otherwise the correct one is chosen automatically)?

The value it gives me in that bottom right hand field labeled ""State Plane Coordinates "SPC (WGS 84)" is basically (a few extra decimal places) the same value given under the IGS08 label which would seem to indicate that it is reporting WGS84.

I would very much appreciate any documentation on how to use DPOS and read the reports. I have referred extensively to the OPUS documentation as it is of course very similar. I worry that as a novice to this that there are underlying assumptions I am missing.

A couple other quick questions:

Why is there an extra digit in front of the UTM Easting values (it is a 5, possibly referring to the UTM Zone)?

The UTM Zone is consistently specified incorrectly, where it should be 5N (Alaska) it is labeled as 53 (Russia). The coordinates appear to be correct otherwise. Is it just that all three of these things are due to typos/glitches in labeling? If so it would be reassuring to specifically know that- at a novice level it is hard to take the output at face value when it appears contradictory.

Thanks again!
 

Matt Johnson

Well-Known Member
5PLS
Report Coordinate System is only meant to be used for changing the coordinate system to some other system than the default one for that area that is automatically selected.

I am not sure why it is selecting UTM 53N instead of 5N.
 

Alexey Razumovsky

Well-Known Member
JAVAD GNSS
5PLS
Report Coordinate System is only meant to be used for changing the coordinate system to some other system than the default one for that area that is automatically selected.

I am not sure why it is selecting UTM 53N instead of 5N.

We did this incorrectly. Wrong UTM zone notification happened as is shown below
1553517348217.png

It works fine for 2 digits UTM zone ID.
 

Alexey Razumovsky

Well-Known Member
JAVAD GNSS
5PLS
If I specify a "Report coordinate system" such as EPSG:4326 the output I get for the bottom right set of coordinates is confusing. The result shows up labeled as "State Plane Coordinates" "SPC (WGS 84)" and appears as degrees minutes seconds N and W. Except for the confusing State Plane Coordinates and SPC labels this would appear to be the WGS84 coordinates I am looking for. I don't believe there is an existing state plane system using WGS84.
DPOS accepts zone abbr for manual input
https://geodesy.noaa.gov/library/pdfs/NOAA_Manual_NOS_NGS_0005.pdf
Example:
State abbr
Alaska Zone 1 AK_1
Alaska Zone 2 AK_2
Alaska Zone 3 AK_3
Alaska Zone 4 AK_4
Alaska Zone 5 AK_5
Alaska Zone 6 AK_6
Alaska Zone 7 AK_7
Alaska Zone 8 AK_8
Alaska Zone 9 AK_9
Alaska Zone 10 AK_10
 

Alexey Razumovsky

Well-Known Member
JAVAD GNSS
5PLS
The value it gives me in that bottom right hand field labeled ""State Plane Coordinates "SPC (WGS 84)" is basically (a few extra decimal places) the same value given under the IGS08 label which would seem to indicate that it is reporting WGS84.
In a case of unknown SPCS we repeat here IGS08 coordinates with one more digit.
 

Alexey Razumovsky

Well-Known Member
JAVAD GNSS
5PLS
New DPOS has been deployed. False (Alaska only) UTM zone indicator fixed.
 

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