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Pre-registrations are open for the Nordic International Hydrometry Workshop 2024.
Pre-registrations gives us a bit of a better picture on how many are coming and how to arrange the different sessions.
Please pre-register here: https://hive.smhi.se/index.php/apps/forms/s/4CMtPkkEHXii2T9Awa3w2Npr
A couple of iterations later we added some knurling as well as a hook for a lanyard. Latest iteration is without the hook and instead we made a hole that we thread some paracord through which also acts as a drain hole and vaccuum release 🙂
Theres a distinct risk of overengineering when you have your own 3d printer, thats for sure!
Cheers Daniel!
I think we will have to modify our sampling regime a bit. Will this help with the issue of the instruments being nearly impossible to communicate with as the memory was filled?
/Daniel
Hi Kevin,
I’ll set up a forum for point velocity meters in the flow measurements section, that is obviously missing.
Not sure where ultrasonic time-of-travel meters would fit. Either in technology catch all, or perhaps we should have a section for hydrological station tech? Index-instruments, ultrasonic ToT, pressure sensors, shaft encoders etc?
Im very open for suggestions!
It looks quite interesting and has garnered quite a lot of interest in our group as well. I know Surfbee has registered on these forums so I alerted them to this discussion.
I do love that their remote control is somewhat waterproof…
/Daniel
Hi Nick (and everyone else),
Its great to hear that things are moving forward in the software side of things.
Nick: Elevation data is quite restricted in Sweden for what was until recently historical reasons…
I can however probably dig out the cross-sections which will include topography. I’ll put you in contact with one of our researchers who you’ve also met in Scotland, David Gustafsson. He is also a satellite guy so I’m sure you have a lot to discuss.
We are not likely to enforce the use of GPS anytime soon in Sweden, however, we are slowly moving towards using it a lot more often for the following reasons.
- Surface velocity
- Input to our flood forecast modelling
- QA/QC
Most of our RS5 measurements are being done with RTK-GNSS now even.
/Daniel
Schematic can be found here: https://www.axis.com/dam/public/18/a0/68/axis-p1378-le-network-camera-en-US-115406.pdf
Its quite a robust aluminium housing. Single PoE cable goes through the mounting arm if you want to, so you could put it up without exposing any cables.
We could arrange a video call if you wanted to have a visual demonstration.
We also saw the same model of camera being used for on-board processing of surface velocity at the regatta this fall outside of Lyon. The company was called Tenevi if memory serves me right. So, instead of sending a lot of videos, you get the discharge directly…
/Daniel
Hi Nick!
We do have a complete LIDAR scan of Sweden done by the swedish land survey. I think the average resolution is 4 points square meter, the DEM is in square meter resolution with the four points average to give the elevation.
Bathymetry is more scarce, some rivers have had cross sections mapped as part of local flood risk assessment projects and there is a compilation of data and available cross sections somewhere…
As for SMHI:
We store our measurements in WISKI, but there is not a complete bathymetry import from the ADCP-data. I think we get width and maximum depth, but that is all. We have historically rarely used GPS for ADCPs so there is not much geographical referencing available.
We do however do a fair bit of topo/bathy mapping for hydraulic modelling of rating curves.
I think bathymetry and surface alpha exports from Q-rev is in the pipeline, that could be quite useful if one would want to start building up a database of locations where a surface velocity measurement could be performed?
/Daniel
Hi all,
So, we finally got a new hire who was given the above tablet as her first field computer.
She hasn’t used it extensively yet but is not very happy with its performance so far. It is top heavy and tends to tip backwards and there are some connection issues between the keyboard and screen. I will ask her to give a more in depth review of it.
I heard that the ports are indeed waterproof even with the port covers open.
/Daniel
Hello all,
If you need a personal invitation letter, please email me at daniel.wennerberg@smhi.se and I will arrange one for you.
Best wishes
Daniel
To state the obvious: It must be something wrong in the Emlid VTG data. Either the output or the readings. Or in the RS5 VTG reading. Is it possible to connect another gps (another brand) to the rs5 to see if you have the same issue? If so, the issue is how the RS5 reads/interprets the VTG data. Another suggestion: If it is possible to connect the Emlid to a PC/PDA/phone and read VTG data, try walking north at 1 m/s and check if VTG data agrees. (Or: Return GPS and rs5 to manufacturer/dealer and tell them that something is wrong)
I’m in touch with Sontek about some other issues, I’ll add this to the pile..
Dave: Thank you for confirming my hypothesis, I will try to do a fast transect and see whether it starts to align better. I must say with the RS5s slight issues with bottom tracking, GPS has been very useful. What is a bit concerning is that of course the discharge with a bit of lost bottom track tend to be biased slightly low.
Another question, which may deserve it’s own topic is that the RS5 reports altitude based on a “non-published, proprietary geoid” instead of pulling height above the ellipsoid from the GGA string. The geoid seems to be quite close to MSL, but since it is “secret” altitude mapping with the RS5 is, at least from my limited geodetic abilities, impossible?
I know the raw gps data is exported into the Qrev matlab files. Can we also pull altitude above ellipsoid from Qrev Dave?
/Daniel
