I don’t have that level of detail and haven’t personally done any
of the processing, I just know that on the Google Fiber project
they would drive a bunch of streets in a city and then the
dedicated server would run for two or three days to create a
usable point cloud data set. Then it had to be hosted on a
separate server due to space requirements. This process was done
by a company who specialized in these LIDAR projects so they had
the tools to do it the most efficient way. I would guess the
overall project file sizes were a couple of terabytes. If you
think about it, you have to have a data record for everything you
can see/reflect from because that data is used to recreate that
object in 3D, so the latitude, longitude and elevation needs to
be built for something as simple as a road sign, all the points
on the post and all the points to be able to recreate the sign
and on both sides.
Thank You,
Brian Webster
www.wirelessmapping.com <http://www.wirelessmapping.com>
www.Broadband-Mapping.com <http://www.Broadband-Mapping.com>
*From:*AF [mailto:af-boun...@af.afmug.com] *On Behalf Of *Steve Jones
*Sent:* Tuesday, December 17, 2019 4:49 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] clutter data and drones
Can either of you describe the data size, and processing time?
say clutter per uban square unit (mile kilometers, etc) at this
res takes x time to collect with this particular method, it takes
roughly y time to process it, and it requires z storage.
Generalization is all im looking for here like , current
drone/blimp, sensor tied to an eagle can only collect an x meter
wide path per sweep so it would take y number of sweeps to cover
a square km, the average speed of collection is x meters per
minute and it would take so many fuel stops to gain that coverage
assuming you have that detail of information
On Tue, Dec 17, 2019 at 3:29 PM Brian Webster
<i...@wirelessmapping.com <mailto:i...@wirelessmapping.com>> wrote:
Yes Chuck the post processing time it takes to create the 3
dimensional/axis point cloud data (points with a lat, long
and height value) is massive. When I worked the Google Fiber
projects in California we in cities like San Jose and the
post processing took days on dedicated high end servers for
the limited geographic areas we needed. If you have clutter
data at 2 meter resolution you get a much better result of
treating the clutter as a solid object than if doing that
with 30 meter resolution data. The 2 meter resolution will
have such high accuracy of being able to see each building
and any single tree that might block a path. In the case of
30 meter data, the clutter gets classified as only one type.
So in many non-dense urban areas, the 30 meter square gets
classified as low density urban, but then you don’t get any
information for a tree lined street or even the rural plains
areas where it’s all open crop land with the exception of the
single tree line planted to block wind on typical rural farm
homes. So averaging the clutter classes becomes more
necessary and not treating it all like solid objects.
When I worked for EarthLink and we were designing the outdoor
Wi-Fi network, we did have the 2 meter resolution tree and
building data in Philadelphia. It made a big difference but
as I recall we also paid $250,000 just for that single city
area clutter at that resolution. As you state there have been
business models made on creating this type of data for years.
It’s not cheap to create, so the cost justification vs. the
added resolution accuracy of your intended project is a key
consideration. I do know that NYC has LIDAR data for the
whole city in the public domain, worked nice on the WISP
propagations I did for the NY State broadband map when they
had me produce the WISP coverage areas. In the end it’s all
about who is paying to have that high resolution data
created. If the government eventually pays for it, then it
should be released in the public domain because the public
funded it (just like their existing map data is today). It’s
still going to take a lot of computing horsepower to digest
and use that data in any RF propagation tool however.
Thank You,
Brian Webster
www.wirelessmapping.com <http://www.wirelessmapping.com>
www.Broadband-Mapping.com <http://www.Broadband-Mapping.com>
*From:*AF [mailto:af-boun...@af.afmug.com
<mailto:af-boun...@af.afmug.com>] *On Behalf Of *Chuck Hogg
*Sent:* Tuesday, December 17, 2019 12:46 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] clutter data and drones
I thought I would chime in here a bit. Not disputing Brian
or anyone else here, as many accurate statements have been made.
I've done some LIDAR propagations at 2M vs 30M DEM data. I
found in areas around mountains and hills (consistent in
KY/VA markets) it is very helpful to treat "clutter" as
obstructions. I have reviewed areas where 30M DEM data shows
400 homes serviced, and 2M LIDAR data shows 17.
Going back to the original question, I know 2 people here in
KY that fly drones for Engineering, Architectural, and
Construction firms and I talked to some of the people at
Common Networks, who use some version of Drone Photogrammetry
to create their own datasets. In the construction industry
it is being used to track building things like bridges,
tunnels, commercial buildings, etc. These photogrammetry
drone setups are $2-25k. The Drone Lidar setups are $5-300k
and require much larger drones.
Also, it takes a long time to take this data and compile it.
I know they take anywhere from 3-18 months to do this in KY
depending on how large the area and how high of a resolution
it is.
Here's a pretty good video and some tech in the beginning of
one in use showing 5cm accuracy:
https://www.youtube.com/watch?v=C8piSF40StQ&feature=emb_title
Just an FYI, the opportunity to create a business out of this
has been going on for many years. They have used planes,
blimps, and balloons for years. I could see a move to drones.
Best Regards,***Chuck Hogg*| /SVP/Director of Acquisitions/
*ALL POINTS**BROADBAND *|**/Live Connected./
On Fri, Dec 6, 2019 at 12:14 PM Steve Jones
<thatoneguyst...@gmail.com
<mailto:thatoneguyst...@gmail.com>> wrote:
Brian,
Assuming the software allows you to input your own
clutter data, at high resolution, what impact on
processing the models is there as the clutter data gets
higher in resolution? Are we talking massive percentage?
I think im maybe overestimating clutter datas usefulness.
I would first need to have accurate topo data that knows
what is ground, and what is treetop/building roof. And
that data really would need to be at the same, or better
resolution than my clutter data. (if my topo data is 30
meter, and my clutter data is 3 meter, my output will be
best guess on top of the 30 meter average that may or may
not have already included the clutter, depending on when
the sampling was done?)
Am I misunderstanding clutter data? I had thought it was
plotted elevations of clutter, but is it more just
regionated averages? if that question makes any sense
When the topo data was/is collected, are there mechanisms
in play to differentiate terrain from structure/clutter?
Say chicago was collected, would it show ground elevation
or would it show the rooftop elevations as the average
ground elevation?
Back to the original query, assuming a guy had a drone
with the capability of carrying the equipment and the
battery life to not have to constantly recharge. Would a
person be able to collect both topo and clutter data,
that can differentiate it, and at a fine detail. What
kind of data size is that information? I know that the
data available to radio mobile in the day could be
downloaded over dialup given some time, so it didnt seem
to be overly massive.
On Fri, Dec 6, 2019 at 9:07 AM Brian Webster
<i...@wirelessmapping.com
<mailto:i...@wirelessmapping.com>> wrote:
Clutter data in the public domain is mostly 30 meter
square resolution. Cameron has talked about a lot of
the issues with the data. Radio Mobile (and
TowerCoverage since it runs on that) has the ability
to tune the cluster classifications a bit. I worked
with Roger in implementing that clutter model. It is
not actually part of the Longley Rice propagation
model, what he did at my begging was allow a user to
manually edit the height and density for each clutter
class and then the tool assigns a loss factor per
pixel/30 meter square of clutter and then subtracts
the sum total of the clutter loss for the ray being
propagated. This is not perfect but when the cell
companies use their expensive propagation tools, they
tune their clutter models for each market by drive
testing a known transmitter with a roving unit and
run those drive test results against what the
software thinks the signals should be. In this
process they compare the know clutter classes that
were propagated through and it self-tweaks the loss
factors is applies for each clutter class. In radio
mobile you do basically the same thing but without
automation. To get it right you have to go out and
measure a lot of your real world signal levels and
manually run propagations until the two match (minus
your fade margins built in to your plots).
This works well if you spend the time, the bigger
issue is that the 30 meter square is assigned just
one clutter class code. In general it works well for
free stuff. The reality of knowing about specific
tree lines alongside a house or in urban environments
with tree lined streets or in back years, those
individual trees to not get factored in to your
propagation, just the building losses if that
building clutter is set to a height to show as an
obstruction(in WISP cases most are not if you are
mounting your antenna on the roof for average
suburban clutter). The answer to this is to have
higher resolution clutter. The terrain data used is
10 meter resolution, meaning there have been hard
data points gathered at least every 10 meters
horizontally and interpolated. Some terrain data is
available at 3 meters but that is not as widely
available. So the issue remains how do you get better
resolution clutter data. LIDAR can indeed be used and
the best versions are actually driven on the streets
and not flown from the air. As Cameron mentioned
however that data still only gives you the
height/size/area where the clutter is. It does not
tell you what type of class that it is and/or what
type of RF losses each pixel of that data should be
assigned, plus you are typically only getting the
clutter data from the street facing side. Think of
the old movie sets and only seeing the building face.
Another method of increasing clutter accuracy is to
resample the data from 30 meter pixels down to
smaller sized pixels. This has limited benefit.
Mostly this can allow you to take things like tree
clutter and trim out the highway areas and or
possibly cut out the trees with specific building
data footprints and assign a different clutter class
by pixel. This is very tedious to do on a large scale
and you first have to have other good data sources to
trim or reclassify these smaller pixels properly to a
new clutter class. While all of this gives you a
better physical map of what and where you have
clutter down to a more realistic reality, you would
then have to go back and manually recalibrate the
tuning because tuning over larger pixels is an
averaging process using the single clutter class. As
you might guess all of this takes time and money. At
some point there will likely be some cool efforts
done by others where we can integrate this. For
instance Microsoft released building outline GIS data
for the whole country that they machine learned from
aerial imagery. That could be used over resampled
data although if the buildings had tree cover they
didn’t get captured in the first place because they
are not visible in the images. There are other open
source projects for things like spectrum sensing on a
Raspberry Pi and software defined radio that if you
put enough sensors out there they might help tune the
clutter loss models. https://electrosense.org/
This is probably way more than you wanted to read
about clutter data and RF propagations but hey I am a
geek like that.
Thank You,
Brian Webster
www.wirelessmapping.com <http://www.wirelessmapping.com>
www.Broadband-Mapping.com
<http://www.Broadband-Mapping.com>
*From:*AF [mailto:af-boun...@af.afmug.com
<mailto:af-boun...@af.afmug.com>] *On Behalf Of
*castarritt .
*Sent:* Thursday, December 05, 2019 4:47 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] clutter data and drones
Google maps uses some of the 1M resolution LIDAR
data. Check out Austin, TX (maybe most other metro
areas as well?) in google, enable "globe view", and
then turn on 3D. Now use left ctrl and drag with the
mouse to move your view angle. This is the data
cnHeat and the Google CBRS SAS solution supposedly
use. OT: I wonder if any of the usual suspects are
making PC flight simulators that use this data.
On Thu, Dec 5, 2019 at 3:30 PM Steve Jones
<thatoneguyst...@gmail.com
<mailto:thatoneguyst...@gmail.com>> wrote:
The issue with publicly available clutter data is
it seems old, poor resolution or inaccurate. If
heat is using the same data as linkplanner, its
definitely bunk.
On Thu, Dec 5, 2019 at 3:26 PM Adam Moffett
<dmmoff...@gmail.com
<mailto:dmmoff...@gmail.com>> wrote:
Have you looked at CnHeat?
We're about to do some testing with it here.
They mentioned USGS LIDAR as one of the data
sources. Presumably that's blended with
other imaging somehow.
On 12/5/2019 4:02 PM, Cameron Crum wrote:
LIDAR is not clutter specific, it just
can't penetrate clutter (it's light) so
clutter ends up looking like terrain. The
benefit is that you get an elevation, the
drawback is that you don't know the type
of clutter or how high it is above the
terrain. I suppose if you compare the
lidar data against a terrain only DEM,
you could extract the clutter height.
Here is the thing... some propagation
does penetrate vegetation to some degree,
so if you are talking about frequencies
that do, then lidar is not necessarily a
good thing to use as everything ends up
looking like an obstruction. You also
need a model that can actually account
for clutter (vegetation) density when
talking about how much it will affect the
signal. Obviously leaf types and things
like that can have other effects, but I'm
unaware of any model that goes to that
depth. While some account for clutter
heights to use diffraction losses and
some lump-sum type losses for a given
clutter category, none of the models that
are in use in the wisp industry account
for clutter density and there are only a
few in existence that do.
You can get high res clutter data
(types) from thermal satellite imaging
from one of the geospatial data companies
like Terrapin Geographic, or SPOT. It is
surprisingly accurate and is what real
prop tools like Planet use. The downside
is no elevations, so you still have user
input for that. Unless you are willing to
shell out big bucks, don't bother
looking. We are talking about 10's of
thousands for a modestly sized area. The
cellcos can afford it.
On Thu, Dec 5, 2019 at 10:41 AM Adam
Moffett <dmmoff...@gmail.com
<mailto:dmmoff...@gmail.com>> wrote:
Interesting. And unfortunately I
don't know any more about LIDAR than
a Google Search does.
On 12/5/2019 11:27 AM, Steve Jones wrote:
Just the SAS administrators will
be competitive product. So
garbage in garbage out will
really apply. Basic SAS
functionality is uniform, but
feature sets will differ. More
accurate propagation modeling
every night will be something we
benefit from and Im thinking that
will be one of the things they
compete against each other with.
They didnt say that specifically,
but the second iteration of SAS
will be more bigger, potentially
even bigly in its scope. I really
thought it was all going to be
modeled after cellco, with a bend
toward cellcos overtaking CBRS
with shady handshakes and
involuntary roaming agreements,
but it appears winnforum isnt
just government lackeys, the
people involved have actually put
gear in the air or at least
listen to those that have. I
think cantgetright may have been
a co-chair of a committee somewhere
Where would a guy who doesnt know
what LIDAR is go to find out more
about that clutter data?
On Thu, Dec 5, 2019 at 10:12 AM
Adam Moffett <dmmoff...@gmail.com
<mailto:dmmoff...@gmail.com>> wrote:
I think the USGS is making 3D
clutter maps with LIDAR.
CnHeat is supposed to use
that wherever it's available.
I haven't heard how that
relates to the SAS though. Is
this something you learned
from the "450 Lady"? Care to
share?
On 12/5/2019 10:25 AM, Steve
Jones wrote:
first question is if a
guy collects accurate
clutter data, can he use
it in any of the
propagation tools we use?
second, and this is where
you braniacs come in,
what equipment would it
take on a drone to
collect this data?
IIRC drone limit without
FAA is something like 300
feet. would that even be
tall enough to sweep a
wide enough path that it
wouldnt take 300 battery
charges to do a square mile?
I envision a course
plotted drone trip that
will fly over with a
pilot car trailing to
maintain the required
operator LOS.
If you think about how
many miles youve put on
verifying link paths over
the years, its not really
a prohibitive thing.
CBRS and SAS is whats
driving this query, but
general propagation
anomalies creates quite a
pickle that better
accuracy/resolution
clutter accuracy would
alleviate.
Please tell me there is
already a consortium
thats built out a clutter
standard with a clutter
submission mechanism,
that would completely
tickle me silly.
I also dont know the
impact to the propagation
back ends as you increase
the resolution of the
data. Im assuming the SAS
administrators are
running something a
little beefier than Radio
Mobile.
I could see this being a
lucrative niche market,
if there were a way
around the drone operator
licensing requirements
(though that cost is
pretty minimal).
Basically a company
builds up a small fleet
of drones, outfitted with
the appropriate gear. You
create an account, input
your coverage area (or
any region) that you want
high resolution data for.
they reprogram the course
and ship it to you (after
collecting the upfront
payment, deposit, and
massive liability
release) they provide you
with a road course to
drive while the drone
does its thing,
anticipate points of
retrieval for recharge,
etc. when its all done,
you stick it in the box
and ship it back. would
be cooler if the whole
thing was transported
back and forth by amazon
drones.
If I had a guarantee
that the collected data
would be useful to the
company, into radio
mobile, link planner,
towercoverage, and SAS
administrators, its
something i could see a
fair price tag of 3-10k
on it for our coverage
area, and no farmers
blasted it out of the sky.
we use clutter data now
thats antiquated so it
would come with the
understanding that
photosynthesis and
bulldozers impact
accuracy from the minute
its collected.
maybe this data is
already out there and i
dont know?
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