Pro Tips
Site Scan Processing
Known issue with Astro v1.5.18 Firmware and Sitescan Reality Engine
If processing photos in Site Scan using the new Reality Engine, the processed map can fail or have strange artifacts, as of April 2024. Astro firmware version v1.5.18 changed how the gimbal attitude was stored in the metadata. The Reality processing engine incorrectly reads this information, resulting in issues with map. ERSI is working on a fix for this soon.
Currently, we recommend processing maps in Site Scan using the Legacy Engine.
Camera Settings
AMC will override these camera body settings:
Shooting Mode dial, if set to P.
Exposure Compensation dial, if set to 0.
Other camera body controls and menu options will be honored. For example:
Focus Mode (e.g. wide, zone).
Exposure Metering Mode (e.g. spot).
Exposure Compensation dial, if set to non-0 value.
File type: JPG and RAW are available.
When shooting RAW files, we recommend selecting File Storage: Camera (SD card). The system will store RAW files to USB, but the transfer time is prohibitively long, imposing a delay of several seconds between shutter releases.
Efficiency Tips
Choose a survey flight path angle that minimizes the number of turns (or in other words, think about maximizing long, straight flight paths). For example, if surveying a complex next to a road that runs at a 30-degree angle, rotating the survey lines to match may reduce the maneuvering Astro has to do and will result in shorter missions and better pictures.
Rotate the survey entry/exit points to start and end at logical places. It is usually more efficient and safe to start at the furthest point from your takeoff location, as your mission will likely end closer to the home point when battery levels are most critical.
Use overlap and sidelap settings suitable for your processing software and output type. AMC's defaults (70%) are reasonable starting places, but reducing these values can allow faster flight and more area coverage. Lower front overlaps will allow Astro to fly faster in a mission, but be sure the value is acceptable for whichever processing software is in use.
Known issue: Photos aren't exactly equally spaced in the flight direction causing some small variation in spacing. This might require a slightly larger forward overlap setting to ensure there is enough overlap in every case.
Tips for Large Projects
Astro can cover areas greater than 200 acres in a single flight at 2cm GSD. Some tips for flying these types of missions:
Uncheck the "refly at 90°" option at the bottom of the Survey settings while planning a mission. This will cause Astro to only fly over the ground in single-direction passes as opposed to a cross-hatch pattern.
If possible, fly from the center of a large survey to reduce the distance between the Herelink and Astro. The maximum telemetry distance is shown in AMC during mission planning if you're at the takeoff location. Being able to have a line of sight to the vehicle at all parts of the survey is important for safety as well as maintaining a solid data link.
Fly at 10-12m/s. The aircraft can fly up to 15m/s, but the flight time will actually increase if flying above 12m/s and result in a longer flight.
A "typical" large area survey might have the following parameters: 12m/s speed, 120m altitude, 70% front overlap, 65% side overlap, and the gimbal angle pointing down (90°).
Astro defaults to limiting the distance between waypoints to 900m. This is intended as a safety check to ensure that an accidental waypoint doesn't send the drone out of range to an unintended location. However, this may limit the length of a reasonable survey in some edge cases. This value can be increased by changing the parameter MIS_DIST_WPS. Do not set it larger than necessary to maintain the safety benefit.
Tips for Small Projects
Smaller areas can be covered the same as a large project, but usually higher detail is desired. In these cases, a crosshatch pattern can be used with gimbal pitch to get better detail on the sides of vertical objects. This gives better 3D reconstructions.
Check the "refly at 90°" option at the bottom of the Survey settings while planning a mission.
Set the gimbal angle to around 70 degrees to get better imagery on the sides of objects.
Fly lower (60m or less) depending on the situation. Lower altitude will result in higher-density photos; just make sure that safety is the highest priority and that no obstacles intersect with your flight path.
Make sure to fly well beyond the boundaries of the object being surveyed when the gimbal is tilted to ensure that it can be seen from all sides.
Generally speaking, slower flights will provide more accurate results.
Aircraft Battery Changes
For normal operation, it is recommended to unplug both batteries, and then connect a new set for each flight. However, the aircraft can hotswap batteries to allow for the continuation of a mission that requires more than one flight. To hotswap, do the following:
Disconnect one of the discharged flight batteries from Astro.
Replace the removed battery with a fully charged pack.
Press the power button on the battery twice and ensure it turns on and says "hotswap" on the new battery's LCD screen.
Disconnect the second discharged battery.
Replace the second removed battery with a second fully charged pack.
Power on the second battery the same way, and ensure both are powered up.
Continue mission after the post-processing for the previous flight has been completed and there is no longer a progress bar on the Herelink.
AMC on a computer
It's possible to plan missions and monitor flights from AMC on a computer or tablet. Here's the procedure to connect another device to the Herelink.
Saving Photos to Camera and USB Simultaneously
Changing a7R-IV Settings
Astro remembers the settings that you can change within the AMC software. Next time you power on the system and when the camera establishes a connection with Astro, Astro will set these settings.
If a setting is not exposed in the app, we are most likely not overriding this setting. In order for these settings to be changed and saved even if the unit is powered off, follow the below procedure:
Using the wheel on the Herelink, tilt the gimbal/camera down at an angle so it's easier to access the buttons on the camera.
Using the menu or “fn” buttons on the camera, change the desired settings.
Turn the camera power off by using the rotary switch on top of the camera.
Wait 10 seconds. The camera takes a while to save settings to its own memory.
Power the camera back on. Confirm that the settings that you changed have persisted.
Resetting a7R-IV Settings
The USB-C connector needs to be disconnected from the left side of the camera to reset the camera settings in Menu > Setup7 > Setting Reset > Camera Settings Reset. Use a thin driver to unplug and connect the USB-C, as it helps with the lack of clearance afforded by the gimbal.
Camera Calibration Parameters
This is a set of example calibration values for the Sony Alpha 7R IVA with Sigma 24 mm lens, which can be used for photogrammetry initial conditions. Each lens is slightly different, but these values are good initial values if the software in use can't solve them directly.
| Parameter | Value |
|---|---|
Focal Length (mm) | 24.351 |
Principle Point X (pixels) | 4714.485 |
Principle Point Y (pixels) | 3172.286 |
R1 | -0.017 |
R2 | 0.071 |
R3 | 0.009 |
T1 | 0.001 |
T2 | 0 |
Inspection Workflow
For inspection, we recommend these settings:
Camera body setting > Focus Mode: Center
Camera body setting > Exposure Metering Mode: Center
AMC setting > Grid: Reticle (which approximates the focus area)
AMC setting > Focus: Auto
Video Workflow
Astro Map is primarily intended for photos, but with some minor modifications it can be used to record video.
Once these settings are changed, you can switch between taking images and video footage using this button in Photo Mode:
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