Is Anybody Using SALSA (Surveyorƒ??s Applications for Least Squares Adjustment)?

We use it everyday as it was designed with/for us. It is very powerful and free to the public now.?ÿ

@StLSurveyor - Hello St Louis! Greetings from Maine and thank you for your reply!

I'm interested to hear what types of dissimilar spatial measurements that you are using in SALSA.

• For example, does SALSA natively read RINEX files?
• Can you enter tape and compass measurements?
• Can you enter CEFB-CMM files into SALSA?

Does the user have to know programming and writing custom scripts in order to get their terrestrial data imported into SALSA?

Per the manual the support formats are:

Instrument and File Types Supported

ƒ?› GeoLab format, typically .iob
ƒ?› Leica Sets of Angles format, typically .log
ƒ?› Trimble Data Exchange Format, typically .asc
ƒ?› grape/merge Precise Point Positioning format, typically .log
ƒ?› OPUS Precise Point Positioning format, typically .opus
ƒ?› Leica Levels data, typically .gsi. Both GSI-8 and GSI-16 data formats are supported. Only BF and BFFB line leveling methods are currently supported.?ÿ

Instrument and File Types Supported
At time of writing, salsa can import from the following instrument or file types; each
of these converters is available under the Import menu:
ƒ?› GeoLab format, typically .iob
ƒ?› Leica Sets of Angles format, typically .log
ƒ?› Trimble Data Exchange Format, typically .asc
ƒ?› grape/merge Precise Point Positioning format, typically .log
ƒ?› OPUS Precise Point Positioning format, typically .opus
ƒ?› Leica Levels data, typically .gsi. Both GSI-8 and GSI-16 data formats are supported. Only BF and BFFB line leveling methods are currently supported.

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We process our GPS Absolute PPP through Proprietary Government software and other GPS vectors in TBC. All TS work is with Leica instruments. We have been playing with Trimble TS files kicks it out, but sometimes if the data contains measured rounds SALSA. All GPS data is processed outside of SALSA.?ÿ

Can it read native Rinex - no

Can you enter tape and compass - yes

CMM - no, but you can key in point values

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Hi StLSurveyor,

Thank you very much for your reply. I appreciate your insights since you say that SALSA was designed for you and that you participated in that design process.

I found the files listed that SALSA can import in the Appendix, and not exactly intuitively entitled: Conversion of Instrumentation Output

Getting dissimilar spatial measurements into SALSA v1.13.0 is presently limited. Every GNSS OEM has its own proprietorial format, but they all provide tools that convert those files to RINEX. I'm very surprised and bummed to learn that SALSA is unable to support RINEX. Since federal funding was provided by the NGA, this lack of support for RINEX is even more puzzling. What were the reasons for not providing support for RINEX files while SALSA was in development? Are you able to lobby that SALSA's next update include RINEX support? Thank you for any consideration doing this.

GeoLab? Never heard of them before, but now that I do, and see they sell least squares software I couldn't ever afford (even more expensive than StarNet), it's not surprising that I was unaware of GeoLab. It's good to know that SALSA is open source, and I want to thank you for helping to make it, and hopefully, continue with its development.

I cannot find any survey applications or surveyors who know what grape/merge Precise Point Positioning format is. I think most surveyors know what PPP is, but what is grape/merge? Is this something most surveyors ought to learn about even if they never intend to use SALSA?

Besides supporting the ingestion of Leica and Trimble data collector files, are their any plans to widen support to other formats?

CMM stands for Cadastral Measurement Management. There may be some users on this forum that still use it because it remains rock solid, powerful and quite adaptive to multiple least squares scenarios despite it having not been officially developed after the end of 1998. Informally, it did get some updates into the mid 00's by awesome UMO alum.

I understand your concerns, however, It's my understanding that SALSA was not designed to process raw GPS data nor was is planned to be used or funded to support private practicing land surveyors, which is one reason why RINEX is not support. Another reason is the agencies that use SALSA use other software for our absolute positioning that is not available to the public. Regarding GRAPE, the format/output it is of no concern to the practicing private surveyor so I would suspect you will find none. SALSA is designed to work with a geodetic/geodesy mindset not a land surveyor's mind.

Regarding CMM, I am familiar with the software but SALSA users have zero interest in cadastral data so CMM was never considered.

Updates are always on the table, but I would be very surprised if RINEX and CMM formats would be supported due to the main objective of SALSA.?ÿ

I would look into OPUS Projects for all of your RINEX data and your plans. You could use OPUS Project to manage all the RINEX data processing and overall adjustments. CMM data can be brought into SALSA in a basic point file and then you could combine in SALSA for a final adjustment if you wanted.?ÿ

I am a grad from UMaine myself perhaps I can convince Ray to fill in the gaps ???? He is always up for programming challenge!

Posted by: @kelly

I'm very surprised and bummed to learn that SALSA is unable to support RINEX.

I'm not.?ÿ Near as I can tell, SALSA is an adjustment application, not a baseline processor.?ÿ RINEX files contain raw GNSS observation data, and turning that into vectors is the province of baseline processor software, not adjustment software.?ÿ Star*Net is similarly unable to use RINEX files.?ÿ TBC can because Trimble realized early on that its users needed a way to adjust their processed baselines, so they came up with TRIMNET and eventually rolled both capabilities into what is now TBC, with a price tag to match.

Exactly, when the software was written originally for government use they weren't thinking about free software for the private guys. There is other free stuff out there such as OPUS (as I mentioned) that will process RINEX files. Here in the academic world we only focus on task at hand most of the time.?ÿ

Check out UNAVCO website, they have other academic related/designed software that is used by other agencies.?ÿ

My bad. I thought that since SALSA was adjusting vectors, it should be able to process them too.

Guess RTKLib is the only route for me to go for processing smartphone RINEX files.

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@kelly Yes, especially since you are just using smartphone files and not survey grade.

Dated, but may be of interest:

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https://www.gpsworld.com/7-free-alternatives-opus-post-processing-in-government-shutdown/

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Oh sure, I remember that one, and the similar article by Mark Silver that ran about the same time. I have always used http://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php for independent checks during all of my experiments for the past 20+ years. Many thanks to Ray for informing me about NRCAN's PPP service.

But https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php doesn't like the RINEX files that GPSTest, GnssLogger, or Geo++ Logger produce. The service will accept the submission, but not result has ever been returned.

I've also had difficulties getting them to run through Ashtech Solutions, GNSS Solutions, Topcon Tools, Javad's Justin, and Trimble's RTX online. The only thing that I've found cable of processing the smartphone RINEX files has been Rokubun's Jason.

Part of the issue may be related to nav messages not being written by the Android app, not because of the app, nor because of the OS, but because the phone doesn't support nav. That's easily overcome by manually fetching the ephemerides, but there's still something else gumming up those other programs from processing the smartphone RINEX files, even after GFZRNX has fixed them.

There's a dearth of devices that 1) have the necessary GNSS chip hardware that support multi-frequency/ multi-constellation and 2) have the necessary support allowing for the calling of data from that hardware. Android developers have been excited to make such enhancements to its OS, but OEMs aren't showing the same level of excitement. App development is just beginning and the whole ecosystem is interesting to watch, at least so far in its first season.

Google Smartphone Decimeter Challenge at ION GNSS+ 2021
https://developer.android.com/guide/topics/sensors/gnss

Jason's engine is built from RTKLib and will produce single vectors, but Jason can't do multiple baselines/CORS, or least squares. My friend Isaac, who is a SALSA user and who has been very kind to answer my questions about Rokubun, asked if I ever tried SALSA. That's what got me started looking at SALSA 🙂

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@kelly Wow keep up the good work. Impressive.

@stlsurveyor

?ÿRay! My all time favorite speaker. Regarding all things gps. I totally look up to that guy. Absolute genius. It would be great to get him on here as a member.?ÿ

Is he?

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