all right everybody today we're going to
be talking about a high accuracy
workflow from end to end so I'm here on
site with my coworker s uh who's another
csse customer success engineer here at
drono so we're going to walk you through
the steps from all the way from planning
all the way to uploading and viewing
your data in drone deoy for a high
accuracy Mission so some things we're
going to be talking about today is uh
some consider ations when flying a high
accuracy Mission so this site is 33
Acres we decided because it's a
relatively small site that we're going
to go with a single gcp workflow if your
consideration even with small sites is
that you really need a high level of
accuracy you can do a full gcp map with
all those gcps encompassing that whole
map but for today's purposes we're going
to do a single gcp workflow where we can
still get really good results for a 33
Acre Site like this so some of the
equipment we have on site today is a an
mlid
rs2 and we're going to be collecting the
actual coordinates of these ground
control points and these checkpoints
that we're going to be laying out today
and we also have a mavic 3 Enterprise
with rtk module so we're going to be
flying this site with rtk as well hence
why we're able to do a single gcp
workflow is because we do have an rtk
enabled drone that we're flying all
right so before we get started we're
going to talk about the topics that
we're going to cover in this video we're
first going to talk about flight
planning with the specific
considerations concerning the mavic 3
Enterprise with an rtk module then we're
going to talk about gcp and checkpoint
coordinate collection using an mlid
specifically the
rs2 we're also going to talk about rtk
versus PPK then we're going to go into
flying the mavic 3 inter r with rtk on
this site and we're going to look at
uploading data uh all your photos and
then tagging those gcps and checkpoints
through the Drone deploy gcp tagging
process then we're going to look at
reviewing the data and doing some
quality assurance on making sure that we
got good accurate data on this site all
right we're going to first talk about
planning your flight before ever going
out to the field for your high accuracy
Mission so the first thing we're going
to do is we're going to do a standard
map here now considering that we chose a
single gcp workflow it was based on a
few factors the first one being the
number of acres here this is a
relatively small site so we can get away
with choosing a a single gcp workflow
here and our accuracy threshold for this
isn't super high but you'll see we'll
still be able to achieve sub inch
accuracy on this map flying the mavic 3
Enterprise with rtk and with that single
gcp and first we're going to choose our
altitude here so for high accuracy
missions we really don't want to go
above 200 ft if we want to deliver very
highly accurate Maps when we're talking
about sub inch as you go higher up to
300 400t you lose resolution in your
photos and thus you'll lose accuracy in
your map so if our goal is is to deliver
you know inch to two 2 in or even sub
inch Maps we want to keep it 200 ft or
below if we want to really dial in our
accuracy we would turn this down maybe
do 120 ft of flying this drone and this
equipment setup that we
have the second thing is that we just
want to map terrain we're not super
interested in structures on this map so
since we're only mapping terrain we want
to leave enhan 3D off this will increase
our efficiency of capture and one thing
we're going to want to do just to
understand our planning time and number
of images is change this to a mavic 3
Enterprise in the advanced settings
button there and you'll see this is an 8
minute flight with the mavic 3
Enterprise with enhanced 3D off we can
also understand our rtk coverage right
here so flying with rtk on this M3
enabled drone we can see that we are in
a covered area now if we were
in an area that lacked coverage with an
Amber or red icon here we would want to
um Fly this with a PPK workflow but the
big consideration with PPK here for
postprocess Corrections is that we want
this flight time to be you know about 10
minutes or more so we could go into
enhance 3D and we can turn on just
perimeter 3D here instead of crosshatch
to increase our flight time or if we
didn't want enhance 3D on we can adjust
our flight speed here to be a little
lower and to increase our time to
capture just to ensure that we have
convergence for that PPK
flight one thing to consider is if you
really want the highest degree of
accuracy possible on this map is to plan
gcps for this map on all the corners 50
ft inside the map plan to ensure we have
enough photos so on this map I'd
probably put one up here in this corner
one here one here one here one here and
then possibly one in the center of my
map generally for rtik enabled drones
you really only need one for every 200
images so we have 276 here so we really
only need you know one to two gcps on
this project but if I wanted a high
degree of accuracy I would want to
capture the corners so maybe I would do
four or five just just to capture the
corners of this map and really ground
and anchor those Corners in to a real
world coordinate but I have decided that
for this one we're going to go with the
single gcp workflow so we'll see how it
turns out all right our first step on
getting the S survey done with the
ground control points and the
checkpoints we decided here to start on
the edge of the side with a checkpoint
now a checkpoint is the exact same thing
as a ground control point it's still a
point in the ground that you survey with
your gns station you're going to record
the coordinates and upload them to drone
deploy there's nothing that changed
practically in these points between the
checkpoints and this ones is just that
the checkpoints are not used for
processing but we do need them to
actually evaluate the accuracy of the
site to get the survey in using the
emlet we need to connect the emlet to an
end trip Network and a hotspot in this
point I'm using my device as a hotspot
and I have a connection subscription to
a provider that is inputting the
correction into the emlet whenever you
go and set up that connection you have
to get the credentials from your
provider and they're going to give you
uh a passwort and a username together
with a port number it's very important
to have the correct port number for the
area that you're
surveying once you input that the main
screen that you have to look into the
emlet is going to be on the status the
status is is going to tell you how many
satellites you have en reached right now
and if you're receiving Corrections or
not the most important thing before you
record this is that you have a fixed a
fix is not going to be achieved if
you're too close to buildings or if you
don't have a strong internet connection
now that we have a fix we can be
confident that the coords that we're
going to be recording now are going to
be precise so we place the rod on top of
the target the target is a high contrast
checkerboard Target the most important
thing in your targets is that we need to
be able to see the center precisely as
precisely as possible you can spray
paint it but we suggest if you're going
to do go that route to actually use a
stencil that actually is going to Mark
or delineate that Center as uh precise
as possible as you can see in this one
this nice Target does have in the center
an opening we're going to be placing the
rod you want to have it as level as
possible in this case my rod does have
uh a level um in the side that I just
need to make sure that is not leaning
too far um above the delineation of what
is leveled now to start surveying your
points in emlet is super easy you just
have to start a
survey you create a new survey and here
you're going to give it a name now
besides the name the most important
thing is going to be your coordinate
system your coordinate system the best
way to define it is going to be
identifying the epsg code and just make
sure that you're surveying in a code
that you're actually going to be flying
and processing in drone deploy but also
if you're going to be using the data
outside of drone deploy to have that
same code on whatever design files
projection system you're using so it's
very important to have a cohesiveness on
the epsg code throughout the life cycle
of the capture in this case we're using
a provider that is using wsg84 so I'm
going to try to match their settings
even the vertical datum to whatever
they're using CU it's very important
that this considered the rubber is
matching whatever the base is
projecting and then once we have that
defined we are going to start serving
all right so for this point um one of
the considerations we had is that we
wanted to make sure that when we're
setting up these targets they are 50 ft
away from any obstacles so trees
buildings things that could obstruct the
view from the Drone to the Target when
we're actually doing our mapping Mission
so here we're about more than 50 ft away
from any obstacle we're in a clearing
here and we'll have a really good uh
picture of the this target from the sky
when we do that mapping Mission so we're
getting ready to fly our mavic 3
Enterprise the very first thing that I
do is to connect to a hotspot again and
that's because I'm going to be opening
drone deploy and we want to get rtik
signal so I just connected it to the
hotspot by swiping
down clicking into the Wi-Fi area I'm
looking for my Hotspot right there is
connected so we got good signal coming
back to draw deploy so for this flight
we're going to be flying with rtk uh
instead of PPK we do have good rtk
connection on this site so we're going
to be using rtk as our default workflow
here which means we need to be connected
to a mobile hotspot or Internet
connection on the controller to have
that work in drone deploy um if we were
using PPK we would want to turn off that
uh internet connection Al together and
upload those uh MRK and OBS files which
we'll talk about later for flying with
PPK versus rtk rtk is going to be
realtime kinematics so we're going to be
making corrections to these images from
the Drone in real time so that's uh why
we require a strong internet connection
and our TK coverage at this site where
PPK you would want to fly that in sites
with no coverage or limited coverage on
our rtk Network also anywhere where you
may not get like an internet connection
on the controller um the the key
takeaway there is you know you want at
least 10 minutes for for convergence
time on PPK we do advertise in fast
regions you know around 2 minutes but I
I definitely suggest trying to get that
flight time around 10 minutes for a PPK
flight
all right as we're getting ready to
start a flight checking our altitude and
everything we're satisfied airspace is
good rtk coverage is green I can start
my pre-flight
checklist submit it here is a good idea
again to check that rtk flag if it's
Amber it's still going to give you an
alarm and you can retry that connection
and then make sure that it gets to the
green once that flag is green you're
good to go you should be getting
Corrections for the flight we're going
to click Start flight
and check our
drone it's very important for the rtk
for your controller to remain connected
to your hotspot so just make sure that
you don't disable the Hotpot in your
phone or a hotspot device that you might
be using if you do that during flight
you might you're for sure going to be
losing that correction signal during
flight okay after collecting all the
data on the side I am ready to upload
the images where on the upload tab I'm
going to click new upload I'm going to
choose my files which is going to be
from my SD
card going to try to find the folder for
the images that were captured on this
location which are going to be this
ones I'm going to select all of them if
I do include these two files that
MRK and OBS I will also have a
PPK correction on my
map as we can see in this next screen we
do have more options towards the right
hand side on my map I'm going to click
into that and I do have the option to
add
gcps I can download the right template
over here paste my C coordinates that I
got from the Emet
file which I already
did and we are going to upload that CSV
right here it's going to identify the
epsg code just going to make sure that
one is right and I'm going to start
uploading and then my next step is going
to be to wait for an email to review the
ground control
points okay after the map processes in
the cloud
you are going to get an email to review
the ground control
point so we will click into that
email and then we're going to get to
this screen on this screen the main
thing that we have to do is to make sure
that the crosshairs are hitting the
center I'm going to click on edit to
actually have a closer look on each of
these points they seem to be pretty
decent but it's important to even find
two it to make sure that we don't
introduce any inches of
error by not hitting the center all of
these look pretty
decent and I'm just going to be continue
to continue to review each one of
these some of them are just a little bit
off especially this one in the
bottom you might have more images and
over here in the top if you have this
button it's good to click on
it and it's going to take us to another
screen with more images that actually
touch that
point if I am happy with the aim of all
all of these
points I can
proceed and click on the top submit CR
control point and move on to the next
one since in my CSV I already
had um
labeled two of my points as checkpoints
they already already appear here as
checkpoints but I still have the option
by clicking into this window to change
it to a ground control point or VI Versa
okay after you're happy with all of your
points you can have a final review right
here and then click
submit the map is going to process again
and it's going to get fixed to those
points and you're going to get an email
with that map is ready all right so now
we're going to briefly talk about
viewing our data what after we've
captured uh We've uploaded and we've
processed our
map so the first thing we're going to go
uh and check on is under map details
we're going to click on map and then go
into processing
report and you can see right here that
this is a new feature we're adding we're
showing you what high accuracy workflows
were flown with this specific map map so
here we have rtk gcps and checkpoints
applied to this map now that we're in
the processing report we're going to
look at a few things first so the
average GPS trust here is super low what
this indicates to us is that we had a
good rtk fix on our entire map um the
higher the number is the less trust or
the less quality of an rtk connection we
actually had on this flight anything
less than one here is good number um
this one specifically is .13 Ft this is
what we want to see for our average GPS
trust the next thing you'll see here are
the gcp and checkpoint count we'll
actually look at this in more detail
further down the screen the other thing
to keep in mind here is our coverage
quality so this map right here is
showing us that we had good overlap on
our images you can see some portions
where we had a little bit more marginal
coverage where it's green here in the
middle of the map
this makes sense on this specific map
because we had tall trees that were
captured in the photos so the overlap on
the difference in elevation between the
ground and the top of the tree uh is
going to be less at the top for overlap
than at the bottom on the ground um I
think that's going to be okay here I we
haven't seen any issues to let us know
that you know we have abnormal stitching
or anything like
that and and then finally the tables
that we're really concerned with here
are our checkpoint values so what we
really want to see here are you know
anything less than 2 in is really what
we consider a good map for a high
accuracy Mission obviously we would like
to get these tolerances as tight as
possible so the less error here the
better generally we'll always see better
results in the XY than the z-axis but
overall this looks like a pretty good
map our Z error is less than 2 in and
our XY is sub inch accuracy here also we
don't see any issues with the tagging on
this
gcp and no issues stand out in this
report so single gcp workflow we flew on
this site it was a relatively small site
and we saw good results by placing two
checkpoints throughout this map one on
the North side one on the south side and
and our data is good and we can trust
this for alignment we can trust this for
Earthworks calculations and we can trust
this to pull this these exports like
Point clouds or obj file any geotiffs
into other software to rely on this data
to align to any modeled objects or
anything like the that we have in other
software we can also rely on this data
for pulling in Geo reference files to
ensure that those Geo reference files
will align and draw to play
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