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steveFitz

287 post(s)
#11-Jan-21 06:06

I'm wanting to do an analysis for a client of of a given urban area's canopy cover.

The analysis should ideally differentiate between layer height classes: grass (0-0.5m); shrub (0.5 - 3m); small tree (3 - 10m); medium tree (10 - 15m); and large tree (15m+) as can be seen here. The data in the link is apparently in ERS raster format with a 0.2m cell size.

I've requested to use data from the linked source but am not confident they will give it to me.

Can anyone suggest other sources of such data for areas of Melbourne, Australia?. I've had a brief look at EOS Landviewer portal but I'm not really sure what I'm looking for (LIDAR?).

Steve

tjhb

9,550 post(s)
#11-Jan-21 07:03

Not what you’re asking, but if you have exactly the product you need for the area you need, I would say just pay and be grateful. Don’t shortchange your client, or yourself.

I’m sure CSIRO has some discretion on pricing, depending on who the client is (even though their funding is, notoriously, always being cut).

steveFitz

287 post(s)
#13-Jan-21 23:34

Yes, that was not helpful.

I believe you successfully scuttled my post by characterising it as an unreasonable/unprofessional/unethical request for free data.

Perhaps you have made this assumption about me because I use a low cost GIS product?

I do know a little bit about poorly funded government science/environment agencies as I worked for one for over a decade.

You probably don't realise this but such posts come across as condescending and, in my case at least, discourage me from making future posts.

I should not need to explain that my post had nothing to do with trying to avoid payment for good data or trying to get it cheap but rather trying to get it at all.

If you have ever tried to work with or for LGAs and other (Australian) government agencies you will know that the wheels turn slow and sometimes not at all.

For example, I made a request for the data I mentioned through the "Contact us now to start doing business" link/web form on the page I linked to well before posting here.

As expected I still have not had any confirmation of my contact.

I called up yesterday to see if my request was received and, if so, how it was progressing.

Again, as expected, after some searching for my request in their system the person (anonymous - no name or dept was given) who it was to be directed to was unavailable and no offer to have them call or contact me was made - just an assurance that it *should* be dealt with soon.

I'm running a competitive commercial business and deadlines must be met. When the only source of data for a project is from a government agency I know there will usually be bottlenecks that will slow the project up (unless, unfortunately, I have a direct contact at the agency). In such cases it is prudent to at least know of other sources for the data.

As for supporting CSIRO I don't think their worth should be measured by their earning capacity or external earnings or that they should compete with private industry: they are not geared up for it and, as per my contact mentioned above, not too good at it (they don't have Paypal or shopping carts either!). What they do do well is science research.

CSIRO's worth should be measured by its public good (which would be bountiful). Support probably has more to do with who I vote for come elections.

I would argue that such data as I need to make reports that support improvements to the urban environment and public well-being probably should be open source so they can be used freely and often. This discussion at length however is not, in my opinion, relevant to this forum.

So in future please think before posting responses that add noise to the SNR of the forum.

This of course does not imply that you have not contributed a hell of a lot to the signal side of the ratio which is greatly appreciated.

I'm still up for suggestions for data sources. My deadline is nigh.

oeaulong

304 post(s)
#14-Jan-21 00:48

At the risk of fueling your frustration, I came up with these two on a google search.

https://spatialvision.com.au/lidar-and-imagery-supply/

They imply that the LAS data is available for their product.

Further down the search came this:

https://data.melbourne.vic.gov.au/City-Council/City-of-Melbourne-3D-Point-Cloud-2018/2dqj-9ydd

4GB download seems doable. Unsure if this will cover your AOI.

I found the ELVIS site, but it seemed to indicate that Victoria is not available on Lidar.

The EOS Landviewer seems to aggregate the satellite data, but I do not see lidar as an offering.

good luck.

steveFitz

287 post(s)
#14-Jan-21 01:07

Awesome oeaulong!

That's very helfull. No frustration here!

I'll check out those sites and see how I go (I know City of Melb have an open source data policy so maybe my client won't be charged for it).

oeaulong

304 post(s)
#14-Jan-21 01:11

So do you have a plan for the classification of the lidar? How to segregate or differentiate with aerial and infrared layers to come up with a result?

steveFitz

287 post(s)
#14-Jan-21 04:00

Oeaulong

I've contacted spatialvision.com.au about getting the data and they acknowledge my contact immediately.

The Melb Council data is just a few ks short of my aoi but I downloaded it to play around with.

I've downloaded it into M9 and it is a massive amount of data!

Would I be better off using ERMapper or other software?

I'm flying blind here I must admit.

Any suggestions are more than welcome.

Steve

Dimitri


6,436 post(s)
#14-Jan-21 05:34

Would I be better off using ERMapper or other software?

Don't know about ER Mapper, but usually if it's "massive" data 9 is a good place to start.

Traditionally, the software of choice for big LiDAR data has been a paid version of LAStools (the free version is limited to relatively small data). But a paid license for LAStools is expensive. You can already do very much of what LAStools does using 9, with apparently roughly comparable performance, just different workflow.*

If you have the data, it seems there's always a way to pry what you want out of it with SQL.

*Sooner or later Manifold should do a collection of transforms that are direct 1 for 1 equivalents to the various LAStools utilities. The last time I looked at comparing the lists about 85% were simple SQL to do the same thing. Add a few functions and you'd cover 95+%, which for most people would be more than enough, especially considering it would be $95 and not thousands of euros.

steveFitz

287 post(s)
#14-Jan-21 06:04

Thanks Dimitri.

Luckily the data I will be using will be for a much smaller area than the Melbourne data.

I'm sure my budget won't extend to buying expensive software so I'll take a look at the LAStools free version.

For the moment I'd be glad to experiment a bit in M9 with a portion of the Melbourne data.

Is there a particular part of the manual that I could look at to get started?

Dimitri


6,436 post(s)
#14-Jan-21 06:21

The LAS, LAZ LiDAR topic should be a good start, along with the links it contains.

steveFitz

287 post(s)
#14-Jan-21 06:28

Thanks again Dimitri

dchall8
808 post(s)
#14-Jan-21 21:36

If the data turn out to be categorized, then it's easy to extract by category to make new drawing layers for each category.

tjhb

9,550 post(s)
#14-Jan-21 06:45

I accept that my post was not helpful, though it was meant to be. I don't accept that it was condescending, or scuttled anything.

Why? Just because I don't think that anyone not familiar with the Australian public science environment would imagine for a second that taxpayer dollars would be invested in the production of serious public data, without parallel investment in public access to that data. That would be nuts.

If that is happening in Oz then Oz is flushing tax dollars down the toilet.

Because that situation is inherently unlikely (though I accept what you say, it must be true), it was a completely reasonable reading of your first post that you were looking for a free alternative to reliable, purpose-built paid public data.

(You only have to re-read your third paragraph, where you say you are not confident CSIRO will "give" the data to you.)

steveFitz

287 post(s)
#15-Jan-21 02:45

I really don't want to side track the thread now that it has taken off so I'll make it short.

CSIRO and wasted dollars - most of the stuff I see from them is in report format or derived data from manipulated or analysed primary data. In this case I was given derived data (very course resolution shapefiles) from CSIRO via my client and could download the relevant reports - all free (to client too). No $$ wasted as scientists have done the work and provided it for the public to help inform policies/strategies and the like. I however want to carry out a higher resolution analysis on a smaller area so would like some of the more primary data (part of the imagery mentioned in my post).

I used the word "give" because CSIRO and most of our government agencies have a range of data and information derived from it freely available and in this case the reports and other data was freely given or downloaded (and, yes, a request had been made to my client to request the data also). Perhaps I should have used a better word that doesn't imply give free such as obtain or acquire. If it were a commercial vendor of imagery I would probably have used the word "buy" or "purchase".

My interpretation of your characterising my post was more about your editorialising based on what you thought I was asking for. Perhaps you could have just said something like "if you're willing to pay then CSIRO or commercial vendors may sell ...."

Do they call Aus, 'Oz' in NZ?

dchall8
808 post(s)
#15-Jan-21 19:51

I don't think Tim was being derisive or malicious in his comment. It sounded to me like a suggestion to use whatever is available quickly, pay for it if you must, and pass the expense to your client. The alternative is to spend far too many manhours on the client's clock looking for a better deal.

The users of this forum are extremely happy to discuss and use free data when it is available. The sooner you ask about it, the sooner you'll get a reply. Dimitri has been very helpful providing data sources, and I have tried to pay it back to the forum when I find a free govt data source.

I'm in Texas and it is not uncommon to find commercial vendors selling data which is freely available on government servers. The problem I see with the government servers is they are hard to find and sometimes hard/slow to download from. The commercial vendors provide a convenience, but it's not always (/ever) worth the price. For example the vendor who took over my mapping at the local appraisal district sells their map for $200. When I was there I posted it to our website every week for free download.

Aussie or Ozzy? In the US most pronounce it AH see, as did I until I met some Australian travelers through Texas. They insisted it was "AH zee as in The Land of Oz." Other Australians have insisted just as fervently that it is Aussie, but ironically they pronounced it AH zee. When I pointed it out to them they had to listen carefully to themselves. They said AH see a few times and reverted to AH zee in frustration. Somehow they rationalized the spelling and pronunciation and insisted the AH zee sound was the common pronunciation for Aussie and that Oz was never used.

steveFitz

287 post(s)
#20-Jan-21 03:07

Thanks dchall8. I have indeed benefitted from a ship load of stuff from this forum including links to free data providers! I give back where I can but not as much as I would like (GIS is only a small part of my work and my skills are quite basic compared to others here).

Other Australians have insisted just as fervently that it is Aussie, but ironically they pronounced it AH zee

Aus (pronounced 'Straya by many here) and NZ go by British spelling and pronunciation (although that may be changing with the more recent generations) so apologise (Brit spelling) and apologize (US spelling) are pronounced the same way here and in the US. I'm not sure why Aussie is pronounced Oz-ee but that seems to be the way it is. Look up 'The Last Australian Guitar Hero' on Youtube to hear it sung in a proper Aussie accent (not a Crocodile Dundee Hollywood version, language and low-brow tongue-in-cheek humour warning). I did get tired of trying to correct Americans' pronunciation - to me, in an American accent, it sounds like 'arsey' as in "meet my Arsey friend all the way from Arsetralia.

It appears that my client has been told that the data will be coming so I'll possibly be back with another post asking work flow and methods and if it can be done with Manifold 9.

So do you have a plan for the classification of the lidar? How to segregate or differentiate with aerial and infrared layers to come up with a result?

I read the appropriate parts of the manual pointed out by Dmitri and did some reading up on the Web. I now understand oeaulong's question above but have no actual plan. I'm hoping the data I get is already classified and has infrared data incorporated otherwise I see there are ways to do it, at least partly, in software such as Global Mapper and perhaps QGIS. I would be interested either way in learning if or how Manifold 9 could process point cloud with RBGI raster data.

Dale, I sent you an email so let me know if you haven't received it.

Dimitri


6,436 post(s)
#20-Jan-21 07:32

I'm hoping the data I get is already classified and has infrared data incorporated otherwise I see there are ways to do it, at least partly, in software such as Global Mapper and perhaps QGIS.

As I understand it, your task is simple, almost trivial, in Manifold: take a raster in ERS format that your client has provided and to color it by heights:

The analysis should ideally differentiate between layer height classes: grass (0-0.5m); shrub (0.5 - 3m); small tree (3 - 10m); medium tree (10 - 15m); and large tree (15m+) as can be seen here.

OK. Easy enough. Manifold reads ERS format, so once you have your surface, it sounds like the contour transform, set to areas, would do that in one step. Or, you could just style it, as in the Style: Contouring using Colors topic.

If there's something else, it's not clear what the task is. The "as can be seen here" link in the quote above jumps to an "Urban Monitor™" web page that has plenty of generalities but no specifics, so it's hard to tell exactly what they're selling. [Usually a sign they're trying to sell something simple for a too-high price... :-) ]

The only specific item is the illustration on that page showing a hill shaded surface that in addition to hill shading is colored by height with one palette in regions where land use indicates parks and vegetation and colored with a gray palette in regions where land use is structures and urban land cover.

If that's the task, that's simple to do in Manifold.

For example, it's easy to trace out polygonal areas from clumps of different raster pixels, classified as to land use (there's an example of that in the user manual). You can then use those polygonal areas as you like to manipulate the LiDAR points that fall or don't fall within them. Or, if you're working exclusively with raster layers you can do arbitrarily complex math between different raster layers if you like.

Once you know what data you're working with, if you run into any problems, ask here in the forum. State clearly the data you're working with and what you want to do, possibly posting links to examples to the data, and you'll get plenty of tips.

dale

570 post(s)
#14-Jan-21 23:33

Steve,

late reply, much of the State's data can be accessed via the CIP From memory there is a LIDAr coverage file over in Open Data Vic that will give you an idea of coverage for your site.

DELWP have some land use mapping available including veg cover, might not be suitable at your scale.

Hit the CIP folks first and see what you get.

Email me at my firstnamesurname at gmail, I'll see what I can do to assist.

As an aside, I've been doing Karst sink modelling recently. Bought back pleasant memories.

steveFitz

287 post(s)
#15-Jan-21 02:54

Thanks Dale.

Karst sink modelling sounds very interesting. I would love to hear more about how to go about that (I'll never forget assisting US cavers mapping a cave using tape measures calibrated in feet and tenths of feet!)

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