what i have here is an iphone with a lidar sensor and in the past i've compared this lidar sensor to
a high accuracy total station but today i want to introduce to you pix4d's viadok an rtk gmss
antenna for your iphone the viadoc has the ability to connect to your iphone via bluetooth once
you've attached the vidoc you're able to use the iphone cellular network to connect through in-trip
to your local cores network this essentially gives your iphone the ability to correct its position
in real time we've never seen this in consumer cell phones until now now we've done plenty of
experiments using the iphone's lidar sensor to do mapping work but can we increase the accuracy
by introducing an rtk antenna that will adjust our position today i'm here at ohio state university's
campus testing out the avaya dock in comparison to a surveying total station a surveying total
station is highly accepted as one of the most accurate and precise pieces of equipment in the
mapping industry surveyors utilize this piece of equipment to find relative change in any type of
measurements and because i want to test out the accuracy of the iphone 13 pro with the viadok
rtk antenna i'm going to be comparing all the measurements that we get with that total station
all right let's get started this right here is the largest slope change on ohio state's campus
it connects what is known as the north oval in the south oval which both have a drastic change
in elevation and today we're going to be measuring the slope change using the iphone 13 pro's lidar
sensor while it's attached to the viadok rtk gnss antenna now we're going to be setting nine
different points along the slope of the sidewalk we'll set the backside at the top of the slope
and using our rod we'll be taking measurements at every single one of these points then we'll
be scanning the sidewalk with the iphone 13 pro's lidar sensor with the viadok rtk antenna attached
2 000 years later now i'm going to be setting
one more point right here this will be the location at which our total station sits
all right now we've set all of our control points now the reason i'm scanning this sloped sidewalk
is because i want to put the vidoc rtk to the test i want to see how well it'll pick up on
that change using the iphone lidar sensor and its rtk corrections now to keep everything on the same
coordinate system i'm going to be utilizing a gnss receiver and taking a static observation
on the top of the hill where our backsight will be and at the bottom where our total station is
these points are going to be observed in nad 83 ohio south zone by having the same coordinate
system we can then measure the absolute accuracy of the iphone with the viadon
first thing we're going to do is set up the backsight here at the top of the sidewalk
next i'm going to set up the surveying total station
so
now i do need the height of this total station so i'm going to use this tape to find it
all right and i'm getting an instrument height of 5.16
5.16 all right now i'm going to power on the receiver
and i'm going to power on the data collector first thing i'm
going to want to do is communicate all of my equipment so i'm going to come down to connect
i'm going to make sure that my optical robotics is selected and i'm going to click connect now that
we're communicated i'm going to go over to setup and select backsight i'll now cite our backsight
and i'll click
measure we're going to start by identifying our occupation point which we are occupying point
number 10. our instrument height we measured it is 5.16 the backsight point is going to be point
number one and the height of the rod is going to be 6.56 this is written on the side of the rod
and if we take a look at our errors you can see we have 100th in the northing right on in the easting
and only three hundredths in the elevation i'm pretty happy with this and i'm going to
accept these conditions for our setup all right since i've already got point number one thanks
to the backside i'm going to start with point number two i'll set my rod right over the point
make sure i'm plumb and take an observation all right looks good i'm gonna go ahead and store
next we're gonna do point number three point number four point number five point number six
this will be point number seven point number eight
and finally point number nine all right the last thing i'm gonna do is turn an
angle to the backsight and ensure that the baseline azimuth is still set to zero degrees
all right just found the backside and there we go zero degrees which means that our baseline
azimuth is still set to the backsight and our data should be good all right now that we've finished
surveying using the total station it's time to test out the lidar sensor using the rtk antenna
the first thing you want to do is download the pix4d catch app this is the app that you're going
to want to use that is compatible with the viadoc once you've installed it you're going to see a
live view of your camera and there's going to be a little gps signal in the top left hand corner
if you tap on that you're going to see that there are two types of gps there's the integrated gps
sensor which is the gps in your phone and then there is the viadok rtk via bluetooth
so obviously we're going to want to set the viadoc up i'm going to tap on that
and then a menu will pop up with your information you're going to want to input all of the n-trip
information this is going to connect you to your local coors network so because i'm
in ohio i'm going to be connecting to the ohio department of transportation's vrs coors network
i put in my ip address my port number my username and password then i selected the
mount point that i want to access and then finally selecting the enter coordinate system
this is the cores networks coordinate system at which they're broadcasting their position
once you're satisfied you'll hit save you'll be then given your status as well as your dop number
and there we go now we're rtk fixed which means we're getting real-time corrections on the
position of our iphone and with that we're now ready to survey the sidewalk using the iphone's
lidar sensor with the vidoc rtk if you guys are enjoying this video and you're
excited to see the data set that comes out of it make sure you guys hit the subscribe
button and also follow me on instagram if you want to see more of my professional life
doing surveying and aerial mapping alright and now it's time to start recording data
and good we'll save this project all right and i'm loading up the project and here it is
we can see from the bottom to the top of the sidewalk all of these little
blue squares are the location in which my phone was at very cool i can go ahead and create a tin
really fast and there we go the tin is created oh wow this looks very realistic now and it's a
reconstruction of the sidewalk very cool so now i have the ability to view it on my phone and
it's as simple as that using the iphone's lidar sensor with the viadok rtk antenna now let's head
into the office and analyze this data hello now it's time to start processing the data i've got
right here my iphone with the viadok rtk antenna and i've loaded the pix4d catch app just to the
left of the capturing data button you're going to see a little folder if you tap on that you
can load up all the projects that you've worked on here's our project we looked at this earlier
up at the top you're going to see there's the 3d view there's also the
images and this right here are all the raw images that pix4d captured the main purpose of these
images is to colorize the lidar point cloud and to allow you to be able to differentiate
different features based off of their rgb values however these images do have rtk positioning so
you could do photogrammetric image processing on them as well now up at the top you're going
to see the word upload and what we can do is upload this data set from the pix4d catch app
into pix4d cloud that way we can access the data on our computer so i'm going to tap on upload
and now we have a few things that we can look at we have a bunch of outputs that we can produce
we could create a dsm which will allow us to do volumetric measurements or just have
a 3d perception map you also have the 2d map which will let you develop an orthomosaic image
this is basically a really high resolution aerial of your project you can even do classical image
processing this is running all the images and doing that photogrammetric image processing that
i was telling you about i don't really need to do this for this project since we're just analyzing
the accuracy of the viadox so i'm going to turn these off but you definitely could benefit from
those outputs the most important thing is for you to select your output coordinate system
for me we did this skin in ohio so this is going to be nad 83 ohio south ohio uses the u.s survey
foot so i've indicated that as well the vertical datum is navd88 and again u.s survey feet and
when we're collecting the data it's going to be in ellipsoid height we want to have the geoid height
so we need to introduce the geoid correction so we're going to be using the geoid correction
i'm going to hit done and i'm going to select upload and now it's going to upload my project
to the cloud now i'm going to turn on my computer and load up this project in pix4dcloud inside of
pix4d cloud you're going to see your projects that you've processed and right here i have
my project that i did so i'm going to go ahead and open the project and this right here is the
point cloud that came out of the iphone and it's going to have those corrections from the viadoc
this right here was the top where we had our backsight when we did the total station
so right up here is the top of the hill and we can go all the way down the sidewalk
to the bottom of the hill so very cool now we're going to want to select all
of these points and i'm going to utilize the images that were taken with the phone
so that we can precisely pick the uh pk nails that are in the ground
and ensure that we have the same exact locations as the ones that we took with the total station
i'll come up here to the top i'm going to use the inspect tool to inspect the area
all right and we're very close to that nail i'm gonna try to get a little bit closer
i think we're getting there all right that's almost there maybe one more click
maybe this one yeah that's the one right there now i'm going to use the point tool to create a point
in that location and now we have coordinates for that point we're going to continue to repeat the
process for all nine of the points that we shot on the sidewalk now we've annotated and marked out
all nine locations for where we took shots with our total station all right now i want to export
my data into excel so that i can do a comparison with the coordinates that i got from the total
station if you come over to annotations and select this little cloud it'll export your data in wgs84
now since i'm using state plane coordinates i'm going to manually copy and paste all the
coordinates maybe in a future update pix40 will include the state plane coordinates but for now
i'm just going to select the first point copy my x coordinate which is the easting
and i'm going to paste it here the y coordinate which is the northern coordinate
and the elevation okay and i've added all of the coordinates for all of the points that we've taken
from the iphone scan with the viadox rtk corrections now let's import the total
station coordinates and compare the results this right here is the text file that came
out of the total station i'm just going to copy and paste the coordinates i have organized this
a little bit and in this column this will be our delta y our delta x and our delta z
a simple equation of equals the northing of the iphone minus the northing of the total station
okay and i'm going to drag this over and drag it down all right let's analyze this data
in point number one we were off one tenth in the northing 100th in the easting and
eight hundredths in the elevation i'm actually pretty impressed this is our starting point um
so that's actually pretty good point number two seven hundredths in the northing five hundredths
in the easting and six hundredths in elevation three four hundredths and northing one tenth in
the easting and one hundredth in elevation are you kidding me that's insane four we have five
hundredths and northing a tenth in the easting right on in elevation ah nah that's awesome
it seems that we have a pretty similar pattern here we're 100th off in the northing
five six hundredths in easting seven hundredths in elevation
one tenth and northing five hundredths and easting right on in the elevation right on and northing
four hundredths in easting two hundredths in elevation a tenth a tenth four hundredths right on
a tenth and about a hundredth and for all my metric users out there i've converted
the differences over to centimeters so you guys could better understand the differences between
the total station and the iphone with the vidoc rtk so this viadok rtk antenna is providing us
with one tenth of accuracy in the horizontal and about five hundredths in the vertical that has to
do with the lidar sensor being as good as it is and the viaduct is providing rtk corrections and
they are being implemented correctly into the data sets make sure you guys check out the link in the
description to pick up one of these pix4d viadoc rtk antennas for the iphone 12 pro 13 pro and your
ipad pros make sure you like and subscribe to the youtube channel and i will see you guys next time