Permaculture Site Survey prototype equipment

Hello all,

I am Adrian from Romania, a Permaculture enthusiast, and this is my first post on this lovely forum.

I had to survey a piece of land - well, full of bushes.
So lacking other solutions I made a prototype for a surveying device which made the task really easy - just like a walk about the land, one person operation.
It has the maximum precision for a barometric altimeter of +/-0.1 meters. It has a stationary unit which is the refference unit and one display unit for reading the elevations - these two units can be up to 80 meters away from each other.



I would like to get your feedback if you think it would worth to make this prototype into a series product:
   would you need such a product?
   would you need the data logger function?
   would you want this product as a kit or as a fully assembled product, but costing more?
   would you consider supporting a crowdfunding campaign for industrializing this product?

Please check my site for further details:
https://precisionaltimeter.wixsite.com/mysite

Thank you so much in advance for your feedback, either good or bad, I will take it as a present.

Adrian, that looks like a great idea!  

I presume the units both adjust in sync as the pressure changes while you're surveying the site?

To answer your questions:
1. I probably don't need this but if I did any amount of site analysis or design, I would
2. The ease of mating the data logger to my computer (or devices) would be my biggest concern.  If it was somehow logged into a GPS system or common mapping software I would think it would be very desirable.
3. I suspect most people would want it assembled.
4. I'd consider supporting a crowdfunding campaign.

Additional notes:
Having it able to mount to a pole so that you don't have to set it on the ground and read it at ground level would be nice
I'm surprised barometric altimeters are that accurate - that's cool!

Mike thank you for your great feedback.

Indeed two units are needed to sync the continuous atmospheric pressure changes, every 15 seconds. This complicates the system as two modules are needed - so double the components.
But the reference unit gives also the 0 point - so this can be helpful when finding the level for a swale for example.

Indeed this would be a tool for designers. But maybe at some point, we will all have to contribute and ramp up the reforestation - make a swale and plant some trees below. I don't know... for now we live on petrol and most of the public just does not care... maybe they never will care...

The data logger function indeed looks complicated to interface to other tools. I would not complicate my device with a GPS locator, as those are available already as standalone devices. I try to keep it simple - have a map on paper and mark the elevation points on it. The development effort may be too great with data logger...

What about delivering in the form of a kit - with no soldering required? Just hand assemblies, IKEA style (mounting a PCB with screws on a housing, screwing on the antenna, attaching a cable connector). Would this be an option for a user? The advantage is that - it can be always repaired by the user...

I could make the initial calibration ("0-ing" of the two devices) on a photo tripod. After that the display unit can be held for example at the hip level by the operator that makes the surveying. I noticed that carrying a pole in a bushy area can be difficult. What do you think?

Thank you!

Sure, having a non-soldering "some assembly required" option may be desirable.  I'm guessing it depends on the cost savings for the customer.  For 5-10% of the total cost I'd let you do it. More than that and I'd probably take on the slight risk of messing it up and I do it myself.  Maybe those %'s aren't quite right but hopefully you get the idea.

Putting the base unit on a tripod or table makes sense.  I'd think that if the brush is thick enough to make a stick challenging, putting it on the ground and reading it would also be challenging.  Unless using your hip is accurate enough and then that would work well.  Maybe there's some standard clamp for which you could include attachment points?  Or at least make it easy to tie/tape onto a stick...  

Or I could be overthinking it so go with what you think is best

Do high winds affect the accuracy?

Approximately what do you think these would cost?

Indeed high winds are not the best for barometric measurements. The measurements on the prototype looks quite stable but I think high winds should be avoided...
I will use a tripod for the calibration unit and a monopod for the display unit - so I will attach brackets with 1/4" nuts to the units that can be screwed directly to the tripod and monopod. It will be more accurate. Also will look good. And simple enough. I will update and make a video - when I find some more time.

I am trying to get potential feedback - to find a potential business model for these elevation meters.
As this is a niche product, intended for designers or surveyors, I think I cannot finance an assembly line - thru a crowdfunding campaign.
I could maybe finance finalizing the design and sourcing of all the manufactured components.

But than the only option I see is to find interested partners willing to perform the soldering and assembly - so to have a partners database, in different countries...
I could provide them the fully manufactured kit.
Please, advise your thought.

As a first impression mounting a kit would require about 4 hours of labor (for these two units) - so multiplied with an hourly rate, depending on the country...
The unmounted kit would have a target cost of below 100$ - but I have to double check if this is possible - as it uses Arduino, Adafruit and Hope electronic modules.

I suspect there are a lot of applications but surveying for permaculture is a great one.  Situations where line-of-sight is a problem also come to mind.  

Manufacturing infrastructure greatly depends on if you're making 2, 20 or 2000 a month.  I'd probably plan on making them yourself at first and keep your eyes out for expansion and growth opportunities.  Maybe someone in your country can assemble them as a part time job.  I would think that coordinating builders in different countries might be a challenge.  But you never know.

If the unit is under $100 I think that would be a real selling point, at least in the US.

Hopefully we get more feedback from other people on your invention.  Come on everybody!

I have placed the elevation measurement devices on some regular photo tripod / mono-pod:

So, I would like to kindly ask again for your feedback: is my idea worth it? Or should I drop it?
Thanks
https://precisionaltimeter.wixsite.com/mysite

Very neat!  It would have been cool to see you check a few elevations to show how it works.  Even though I'm sure it works.

But what does everyone else think?

That looks like a great set up.  Especially if that is a realistic price point.  
For reference, this is a unit I use regularly.
https://www.amazon.ca/ZIPLEVEL-PRO-2000-High-Precision-Altimeter/dp/B000N4WYJS
amazing piece of kit, but expensive.

I invented a clear plastic tube "surveyor's water-level" tool. It (plus a tape-measure and some string, and marker pegs) instantly finds the level berm-lines for hugelkultur beds across sloped property (by filling the tube with water). It can also instantly find a perfect gradient of relative elevations for drainage channels. It can also find whether forms for foundations are level, or concrete or gravel driveways are level or will drain. It can also find the degree of slopes (if you also have a string). Okay, it also helps to have a piece of rebar to pound in and tie the plastic tubing to...

Simple.

I would like to see a small cheap lidar tool that can be attached to a drone like a GoPro. Set a reference point, fly to a desired position maintaining altitude and collecting distance-to-ground data. That way you don't have to walk around with tripods to survey the elevation.

hello Adrian-

i commend you for a potentially great little machine-

i just finished a huge permaculture design on a relatively flat piece of property.
For my purposes, i would need accuracy down to the inch (2 cm) minimum. 1 cm would be best.
So your machine being only accurate to 0.1 M (~4 inches) is nowhere near accurate enough.
For a steep property, your machine could be much better perhaps, but consider that 4 inches (0.1M) makes a huge difference in water flows...
I'd consider trying for more accuracy before making it.
I'd buy one for myself if you could do that...

tuffy monteverdi wrote:
i just finished a huge permaculture design on a relatively flat piece of property.
For my purposes, i would need accuracy down to the inch (2 cm) minimum. 1 cm would be best.

As a technical project, this is intriguing. But it's not clear to me how a permaculture plantation is greatly helped by altitude measurements. In other words, what is the benefit of fine altitude measurements?

In calculating the available water pressure for my cistern-based gravity feed irrigation, I just used a laser level to determine the head. What are your purposes that need 1-2 cm accuracy?

If it's $100 and works as well as claimed, I'd buy one. I've been trying to figure out how to map out a cascading series of Miyagi ponds, and this would just be the piece of kit to let me make that happen.

David,

Why to accurately place and build swales of course.
To be able to accurately and successfully control water flows.

I'm thinking how this compares to surveyor's laser I've seen used.

The survey laser is:
ridiculously accurate.  Even annoyingly so.
requires line-of-site
uses a tripod on the reference side, an adjustable measuring stick as the remote.
start at about $400
faster to use when the laser can be seen (e.g. not in full sunlight)

In comparison this solution:
is less accurate ... but maybe still within tolerances?
doesn't require line of site
uses the same basic arrangement
unknown cost
sunlight use/low light use ... depends on the display

I haven't tried to map with a proper surveyor's level, but I've done it with a simple builders level and a 6' measuring stick.  Between that experience and watching others use a laser, I find the laser too sensitive.  Yes, I'd like to have a perfect slope laid out, but if the stick is on top of a clump of grass or not can make a +- 1" difference, and there are other small variations in the soil height as well (was here a gopher hole there? a cow patty? a hoof print? a root?)  Which is to say that there are uncontrolled sources of variation or error that are introduced that reduce the accuracy of the whole system. The best way to deal with the error is by increasing the number of measurements.

Another thought ... the accuracy of the barometer.  Thinking about this, I really don't care if my remote unit has my drop at exactly 5m from the control unit.  What matters is the relative accuracy, or the consistency of accuracy between measurements.  Which is to say ... what is limiting the accuracy?  If the barometer simply can't distinguish air pressure differences less than .1m (and really ... wow that's still amazing) then that's clearly the limit.  If the difference is small variation between the two barometers, then I really don't care.  At some point it would be helpful to know the error distribution (if the distance between measurements is 2", what is the probability of it reading as a 4" difference?)

We generally think of slopes of 1/4" per foot for water flow ... or 2%.  If .1m or about 4" is the resolution then I could place a mark about every 16'.

Another technology comparison is the A-frame and level, walking it along to identify contours.  This is both a) widely accepted as a cheap, easy way to find contours and b) widely recognized as being inaccurate in comparison to a laser.  This makes me think that instead of being a "survey" tool that it might be better considered a "contour finder".

As a land-owner and not a professional, I don't want to spend $400+ on a laser that I'll rarely use.  Something like this, depending on the price, might be a useful tool that I'd use.  Perhaps combined with a builders level (to make sure that spillway is indeed level) this has a place in my kit.

As to some of your questions:

1) I'd be happy with a kit to assemble.  I think a lot of people would not accept having to solder the components (not sure how many people have a soldering iron around... even among this crowd, I'd think very few people do)
2) You might need to offer a "kit +" with a soldering iron so people don't have to think too much about it (and yes, for all of you non-soldering people out there, its easy, its quick and its kinda fun!)
3) standard photo tripod mount would be great (easy to make my own monopod...)

Sorry I mix English and Metric systems...

Came here since this was mentioned in the permies daily email.

I really like ideas like this, and as a mapping/GIS enthusiast, this is right up my alley.

But I'm also a cheapskate with limited storage, so prefering multipurpose tools over single purpose ones. So before plunking down $ I'd be comparing to the following:

1. Modern cellphones (e.g. iPhone since model 6, not sure about which Android ones) have barometers for the past few years. The built in iOS app displays elevation to within +-1 ft or +-1m, and there are apps that display to within +-1cm and allow calibration. There are of course issues regarding absolute elevation, but I understand discrimination of relative elevation differences is about +-30cm (this is from a random quora post, not a reliable reference).

2. Laser level (as mentioned by others) - $400-500+ (US), greater precision than yours

3. Reading off altitude from a reference topo map (or digital DEM/DTM - elevation or terrain model) based on location. Phone GPS accuracy is about +-5m horizontally, but can be ad-hoc improved by locating self using high resolution orthorectified digital imagery. This is downloadable for free or modest $ in many parts of the world: by scraping Google or ArcGis and using NASA's 30m resolution free DEM if there's nothing better, and in many areas much better government sources are available. For instance, in southern Ontario where I live, I can get a 1.2m resolution orthophoto and a 2m resolution DEM. The DEM is over-smoothed and so not quite right around cliffs in particular, but it means I can get elevation +-1 or 2m in areas I care about.

4. Building a 3D model of my land with a drone. This used to take expensive imaging UAVs and expensive by-subscription software (like Pix4D or AgiSoft), but can now be done with a DJI Mavic Mini 250g <$400 drone and pay-by-the-map at mapsmadeeasy.com.  This gives me a 3D model of my land with about 5cm resolution horizontally and vertically, with some hassle and artifacts I have to say.

The upshot is that for a lot of applications, +-1m or so is good enough and with #1 and or #3 I can get it for zero incremental cost with gear I already have. For that your device, though neat, will be a hard sell.
For $400-500 (using #2 or #4), I can get +-a few cm, with some hassle but with gear which has broader applicability for me.

So the niche for a dedicated barometric altimeter like yours, with or without logging, and no matter how well done, is rather limited, at least for me.

I don't mean this to be discouraging. Just deliberately challenging you (as you requested) as you think of whether/how to develop and commercialize this further, and what positioning you'd need to succeed in implementing for it to be a success.

I think I would buy it if you could keep it at or under $100. 😊

Even better if it has a bluetooth transceiver so that I can use my cellphone to record the data.

I found the imagery from the National map of our old overgrown pond area was insanely useful compared to traditional topographic maps. Below is a working analysis of the volume of the pond area achieved by gridding out the image into 20 foot increments. Depths are based on my memory of the pond when I swam in it 50 years ago, supported by the imagery and auto contours overlaid in another image. Traditional topographic map of the same area included for comparison.

I would be very interested in buying one of these, even a prototype, and would be happy to assemble it myself. I think it would be the easiest and fastest way for me to mark contour lines on my land.

Thank you all for your amazing feedback!!
This makes me very happy

I made this device because I had to map a bushy land, by my own (no help...), and I had to do it fast (limited time...).
So I measured 100 points distributed on the land, in 30 minutes, to get a feeling about the land slopes - actually it was a flat land so initially I had no idea where the land was sloping.
The accuracy was enough for me to check where the water was flowing, to be able to determine an irrigation pond location.

The measurement precision is limited to ±0.1 meters, relative to the initial (calibration)  position (this is a barometric altimeter so this is the maximum achievable precision for practical measurements in real conditions - outdoors).
If a better precision is needed, use water level / laser level / builders level etc.
If less precision is enough (1-2 meters) - internet maps can be found.
The device will have a switch for selecting meters or inches measurement.
Target price for the assembled modules around 100$.

I made a short movie with some measurements (indoor for now...):


So, this is a simple fast measurement for medium resolution of 0.1 meters. Does such a device make sense?

Thanks
https://precisionaltimeter.wixsite.com/mysite