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Geotagging Images in Ground Control Software

Transcript: Geotagging Images in Ground Control Software

 Hi, for this video, I’m going to show you how to geo-tag images that have been captured from either your last flight mission or any other flight mission that has been previously completed.

The geo-tagging of images in this tutorial will be carried out with the same ground control software you used to plan your flight mission.

To utilize the geo-tagging portion of your ground station control software, you will need to have flown a mission with one of our RGB color-camera-payloads (The Ricoh PX for the Zephyr 2 or the Sony NEX 5 camera for the Zephyr 3).

Geo-tagging the images captured with our multispectral camera payload, the Tetracam ADC Micro, is now done automatically through the camera’s firmware.

By carrying out the geo-tagging process, all we are doing is associating our GPS time stamps recorded by our ground control software with the time stamps saved within our flight mission image data, or EXIF data, recorded during the same flight mission.

Now, the first thing we will do to start this geo-tagging process is source the log file we produced using our ground control software for the flight mission in reference.

The flight mission log file is always automatically saved for the flight operator on the ground station PC’s hard drive, specifically in the ground station’s software program file.

The ground station flight log file name will include, by default, the time and date so that you can easily verify which flight log should correspond to the flight mission you are trying to analyze.

Once you have sourced the flight mission log file you need, you’re going to want to extract the SD card image information from whatever payload you were flying at the time, and put all of these images into an empty folder on your hard drive for geo-tagging.

Image data is easily exportable from your UAV by ejecting the SD card from the payload you were using after performing your flight mission.

Once you have your log file and image set handy, you’re going to want to hit ctrl+F to bring up the geo-tag flight options menu.

You’ll have a screen pop up here, and from there, you’ll see a button that says ‘geo-reference images.’ Go ahead and click that to get started geo-tagging the images.

Once our geo-tagging menu pops up, we’ll just click ‘browse log’ and select the log file we have pulled from our hard drive earlier that has our date and time stamps on it.

From here, we’re going to hit the browse directory button and choose the file folder that we have previously used to store all of our different images from the flight mission in question.

I have a folder named RGB here that we will select, and once we have selected that, we are ready to pair each set of data and estimate the offset in between the time from when we started the mission to the time that the first picture was taken so that the program knows which GPS waypoints are associated with each image.

To do this, we’re going to click ‘estimate offset’ and the program will read the log file we have given and associate our two sets of data together.

Once we have estimated our offset, which you can see is set to -6247.216, we’ll simply copy and paste that number into the ‘seconds offset,’ box, and once we have done that, we’ll select ‘do it.’

The program will now associate our data pairs together, and you will be able to see a match for each image of our photo set.

So If you have 35 images in your image file, you should have 35 matches if everything pairs up.

After your pairing has been confirmed, go ahead and select ‘Geo-tag images’ to start updating all of your image EXIF metadata data so that each image in your data set has an x, y, and z coordinate associated with it—or the actual latitude, longitude, and altitude at which the picture was taken.

When you import these now geo-tagged images into a post-processing software such as Agrisoft Photscan Pro or Pix4D, the program can identify the exact location and altitude of that image, so that, when photo-processing occurs with the program, the end result offers high-quality data without expending a large amount of system resources and time to perform image data processing.

Even though most post-processing programs can align and process data without needing to first geo-tag the image data, I always recommend geo-tagging your images for the best possible result.

You’re going to go ahead and wait until the program has completed its geo tagging function before moving on, but a message will always alert you when this process has been completed.

You can also generate a KML file from these images when you are done, which will allow you to upload a file directly to google earth so that you can immediately see your image data laid out for you.

Normally, to get a more accurate KML file, you should use post-processing software such as Agrisoft Photoscan Pro or Pix4d, as I mentioned earlier.

Pix4d actually has a menu to geo-tag images by using a Mission Planner log file as the ground station software uses here, however, I prefer to geo-tag the images in the way I have shown you because it tends to be a more consistent way to geo-tag images.

So that’s the process for geo-tagging images, if you have any questions, feel free to contact us through email or by phone and we’d be happy to help!

Thanks for watching and happy flying!

Planning an Autogrid Flight

Transcript:  Planning an Autogrid Flight

Hi, in this video, I’m going to demonstrate the mission planner software on a basic level.

I do encourage you to look over the documentation that is linked on this same page to view everything that is available with the program.

You can also find a download link to the mission planner software on this same page so that you can try all of the things that I’m demonstrating in the this video yourself without having the UAV in your hands, to get a feel of how things work

The first thing you will see when you open up the mission planner software is some of the flight parameters that are available for viewing such as telemetry information, altitude, distance to next waypoint, groundspeed, and so forth, however most of these things are not necessarily going to be useful to you on an everyday basis.

What you are going be using every time you go out and fly is your flight path tab, here, which allows you to set up a flight path for your UAV when you want to go out and collect your images for image processing, aerial photography, or other similar applications.

The first thing that you’re going to want to do is to zoom in to your area of interest—this is just a standard farm in Iowa that I’ve picked out.

You can see zoom in and out here, and choose a map you would like to survey here on the right.

You can also use a google street view map to first do your analysis and then go to the satellite map to better analyze what you’re looking for, for the purposes that you need.

In this video, I am simply demonstrating the function of creating an auto-grid for photo stitching or photo-analysis and creating DEMs and orthomaps and so forth, or for creating NDVI imagery or near-infrared image maps for crop monitoring.

So, now that I have my point of interest and am ready to get started, the very first thing that I’m always going to do is to tell the flight planner that I want to program in an automatic takeoff waypoint.

You can use the manual control of the hardware through the included RC transmitter to take off in manual mode if you wish, however, this is generally for more advanced users, and most of our customers prefer to simply use the program’s automatic takeoff function.

To do this, right click on the map and select takeoff. Tell the UAV what threshold altitude you want the automatic mode to engage in.

In the case of using our bungee launcher, you would want to choose about 10 meters, while for a hand launch, you want to choose about a meter.

From there, click ok and confirm that the 15 degrees of takeoff inclination is ok as well—we’ll stick with that every time.

You can see, here, in the waypoints menu, that we have a takeoff command programmed in at ten meters in altitude, and when the UAV hits 3 meters per second in velocity and 10 meters in altitude, the automatic mode will take over and the UAV will fly through all of the pre-defined waypoints that have been programmed into its memory, which we will set up right now.

Once you’ve synced the UAV with the ground station control software, all waypoints will be programmed in the UAV’s memory automatically and will stay programmed in even without a direct link to the UAV.

To fly an autogrid pattern with the software, right click and select ‘draw a polygon point’ at each corner of the area that you want to monitor—in this case, it’s a square mile of this farm.

You can move these points around afterwards if needed. Once you’ve done that and have a bounding box set up, right click and go to auto waypoint and select ‘survey grid.’

The program will suggest a flight path for you and will tell you about the area that we plan on mapping down here in the grid statistics box; you can see the flight distance and the number of images that will be taken, as well as the predicted ground resolution, and a few other useful pieces of information.

This information will help you to identify whether or not your will be able to complete this mission given your UAV’s battery life (for example, the Zephyr 2 flies for about 60 minutes, while the Zephyr 3 can fly for about 180 minutes).

Knowing that the aircraft flies at an average of 10 meters per second at normal cruise speed and needs to fly a distance of 31 kilometers, given the approximate wind speed, you can roughly estimate how far you will be able to fly with your UAV given the desired flight mission suggested.

As you become more comfortable using your UAV software and hardware, you’ll get better at judging how far your will be able to go given the amount of wind that you have that day.

The ground control software will tell you when you are running low on battery power long before it runs out, however, if you do run out of battery, you can always land in automatic or manual mode in a clearing in your field, or if an operator is available, they will be able to take control of the UAV and guide it down safely for you.

Depending on what payload you have installed on your Zephyr, you can check the camera here—if you are running on the Zephyr 3, it’s going to be the Sony NEX 5 25 mm camera, and from there you can program the flight altitude that you want to fly.

You can also see here that by adjusting the flight altitude, the number of flight swaths that you need to take will change—240 meters will be typical for someone who is doing photo-analysis.

You do need to comply with any applicable regulations, however, depending on the wind’s direction, this would be something typical that people would use.

As a rule, you’ll always want to change the angle of your flight path with the wind’s strength and direction in mind.

If you want to fly the same mission in the same field at a later date, you can load the same flight path, but should always make sure to change the angle of the flight path according to the weather.

I’ll show you how to save and load a flight path in a little bit, but first I want to show you some more advanced options.

If you click this check box here, you can see that these tabs appear. The first thing you’re going to see in the grid options is the amount of overlap.

We suggest a 40% overlap for all of our payloads given that they are gyro-stabilized—it will cut down on the amount of flight paths that you need to take.

If you were using a stationary payload, we would recommend 60-80 percent overlap, but that’s why we have engineered our camera payloads to offer gyro stabilization.

Also, your processing time will be cut down quite a bit when using a gyro-stabilized camera payload vs. a non-stabilized payload as there will be fewer images to process.

Ultimately, the processing resources needed on the server you are using to post-process your photo data will be reduced immensely given the cleaner data that the gyro-stabilized payload our UAV’s come with offers.

If you have any experience with Flying UAV’s in the wind, you should already know that in most cases, it is almost impossible to fly a UAV effectively with a stationary camera payload.

So, most commonly, a 40% overlap should be chosen when doing photo-analysis and flight planning with our products.

In camera configuration here, you can adjust and add another camera. We don’t recommend our novice UAV users to do this but if you are a more advanced user, you can enter a different camera profile here and make it available through the normal camera profile options.

Once you are comfortable with all of the settings from this flight planning menu, you can click accept and the flight path will be programmed into the flight plan here and you’re ready to go.

As soon as you sync your UAV to the ground station, it will know exactly where to fly and when to take photographs.

Depending on the wind speed for that day, the UAV will take either a little more or a little less time to hit all of the corresponding waypoints that it needs to hit.

As each waypoint is met, a camera trigger response will be automatically given to the onboard camera while taking into consideration the preprogrammed amount of overlap you specified during flight programming.

Again, depending on how the wind is blowing on a particular day, the time needed to get to each preprogrammed waypoint will vary; with individual flight time not being a factor for triggering the onboard camera at the necessary points of reference.

The system is designed this way so that cross winds will not bump the UAV off of its required path, and so that all of the waypoints can be met regardless of the wind speed or direction.

If you routinely adjust your angle of flight for wind direction on days that you are flying, over the course of several missions, you will be able generate a very tight set of photo data for analysis that can be referred to by your crop monitoring program—or for generating DEMs and so forth using Agrisoft Photoscan pro, or Pix4D.

Once you have programmed in your grid pattern, you’re always going to want to program in a landing waypoint as well so that you can perform an automatic landing.

You’ll want to pick an area somewhere where you know you have a clearing of about 100 meters, and is free of any trees or other obstructions.

The UAV will shut off its throttle once it gets close to the landing waypoint, and you can either automatically or manually stabilize the wings as the UAV carries out a belly landing.

So let’s say we want to land in this area here.

Right click and select ‘land’ to create a landing waypoint—and you can see this added to the waypoints menu at the left.

The landing waypoint is programmed to disengage automatic mode entirely at 1 meter in altitude and do a belly land as you can see.

You can save this particular mission for flying on another day by going here and clicking on ‘save waypoint file.’

You can delete a mission by selecting ‘clear mission.’

We can also load another mission very simply; I’ll demonstrate that for you here.

(This section will be modified as we want to show the user we can just re-upload the same mission we just programmed in, saved, and reloaded as a demonstration.)

As you can see, the same flight mission loads ready for you to fly without having to reprogram any of the flight waypoints.

All you need to do is adjust your flight angle to compensate for any wind and you are ready to scan your flying area in exactly the same way as you did on the previous flight.

That’s the general premise of programming a lawnmower pattern for flying an auto grid flight mission.

Another couple of other options that may be useful to you as you learn how to fly is return to landing.

Anytime you choose this setting while flying, the UAV will abort it’s preprogrammed mission and fly back to the takeoff point or initial UAV sync point.

You can also do a few other things here.

If you use the rally points command, you can tell the UAV to land at a predetermined landing area of your choice if there’s ever a problem to where you would run out of battery power or would otherwise need to perform an emergency landing and cannot do so due to the UAV being too far from its initial launching point.

I would suggest taking a look at the documentation for the mission planner ground control software for a more comprehensive look at how to use this software.

I hope you enjoyed this video and feel free to ask us any questions about planning an autogrid flight mission by email or by phone.

Thanks for watching and happy flying!