Ground control point assignment and determination system
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for ground control point assignment and determination. One of the methods includes receiving information describing a flight plan for the UAV to implement, the flight plan identifying one or more waypoints associated with geographic locations assigned as ground control points. A first waypoint identified in the flight plan is traveled to, and an action to designate a surface at the associated geographic location is designated as a ground control point. Location information associated with the designated surface is stored. The stored location information is provided to an outside system for storage.
1 . A computerized method comprising:
receiving a flight plan to perform a job using an unmanned aerial vehicle (UAV), wherein the job includes inspecting an area and the flight plan identifies one or more waypoints proximate to or within the area;
for at least one of the one or more waypoints:
navigating the UAV to the waypoint; and
executing, by the UAV prior to the job, an action to designate the waypoint as a ground control point (GCP) including:
determining a three-dimensional position of the UAV at a time of designating the GCP;
determining an altitude of the UAV relative to a ground surface using one or more sensors;
computing, based on the altitude and imaging geometry of a camera of the UAV, a projected ground coordinate corresponding to the GCP;
wherein the projected ground coordinate defines a geographic location of the GCP using a separate imaging or localization operation distinct from imagery captured during the job; and
performing the job by capturing, using a camera of the UAV, images usable to generate rectified images associated with the inspection of the area based, at least in part, on the projected ground coordinates of the GCPs.
2 . The computerized method of claim 1 , wherein the flight plan includes a speed at which the UAV is to travel between the waypoints.
3 . The computerized method of claim 1 , wherein the UAV is equipped with sensors to actively monitor and detect obstructions, wherein the one or more sensors include at least one distance sensor configured to determine the altitude relative to the ground surface used in computing the projected ground coordinate.
4 . The computerized method of claim 1 , further comprising:
receiving, by the UAV, an instruction to modify one or more geographic locations assigned as GCPs.
5 . The computerized method of claim 1 , wherein computing the projected ground coordinate further comprises:
determining an offset between a Global Navigation Satellite System (GNSS) receiver of the UAV and a center of the camera; and
modifying the projected ground coordinate based on the offset.
6 . The computerized method of claim 1 , further comprising:
providing the captured images and stored location information to a photogrammetry system for processing,
wherein the photogrammetry system uses the projected ground coordinates of the GCPs to generate ortho-rectified imagery.
7 . The computerized method of claim 1 , further comprising:
receiving, via a user interface, input specifying selections of one or more locations;
determining the flight plan for the UAV based on the one or more locations; and
transmitting, to the UAV, flight information including the flight plan via a wireless or wired connection.
8 . The computerized method of claim 1 , wherein computing the projected ground coordinate further comprises:
capturing imagery of the GCP while the UAV transitions from a first altitude to a second altitude;
determining a perspective transformation associated with the camera based on the captured imagery; and
refining the projected ground coordinate using the perspective transformation.
9 . The computerized method of claim 1 , wherein:
the three-dimensional position of the UAV and the altitude relative to the ground surface are each associated with a timestamp; and
the projected ground coordinate is computed using position and altitude measurements corresponding to the timestamp.
10 . The computerized method of claim 1 , wherein computing the projected ground coordinate further comprises:
determining a ground surface plane using distance measurements obtained from a plurality of locations proximate to the waypoint; and
projecting the three-dimensional position of the UAV onto the ground surface plane.
11 . The computerized method of claim 1 , further comprising:
determining that a variance between multiple projected ground coordinate calculations exceeds a threshold; and
in response to determining that the variance exceeds the threshold, recalculating the projected ground coordinate using updated altitude or imaging geometry data.
12 . An apparatus, comprising:
one or more non-transitory storage media storing instructions that, when executed by one or more processors, cause the one or more processors to:
receive a flight plan to perform a job for an inspection of an area using an unmanned aerial vehicle (UAV), the flight plan identifying one or more waypoints proximate to or within the area;
for at least one of the one or more waypoints:
navigate the UAV to the waypoint; and
perform, by the UAV prior to the job, an action to designate the waypoint as a ground control point (GCP) including:
determining a three-dimensional position of the UAV at a time of designating the GCP;
determining an altitude of the UAV relative to a ground surface using one or more sensors;
computing, based on the altitude and imaging geometry of a camera of the UAV, a projected ground coordinate corresponding to the GCP;
wherein the projected ground coordinate defines a geographic location of the GCP using a separate imaging or localization operation distinct from imagery captured during the job; and
perform the job by capturing, using a camera of the UAV, images usable to generate rectified images associated with the inspection of the area based, at least in part, on the projected ground coordinates of the GCP.
13 . The apparatus of claim 12 , wherein the flight plan includes a speed at which the UAV is to travel between the waypoints.
14 . The apparatus of claim 12 , wherein the UAV is equipped with sensors to actively monitor and detect obstructions.
15 . The apparatus of claim 12 , wherein computing the projected ground coordinate further comprises:
determining an offset between a Global Navigation Satellite System (GNSS) receiver and a center of the camera; and
modifying the projected ground coordinate based on the offset.
16 . The apparatus of claim 12 , wherein the instructions include instructions that, when executed by the one or more processors, cause the one or more processors to:
provide the captured images and stored location information to a photogrammetry system for processing,
wherein the photogrammetry system uses the projected ground coordinates to generate ortho-rectified imagery.
17 . The apparatus of claim 12 , wherein the instructions include instructions that, when executed by the one or more processors, cause the one or more processors to:
receive, via a user interface, input specifying selections of one or more locations;
determine the flight plan for the UAV based on the one or more locations; and
transmit, to the UAV, flight information including the flight plan via a wireless or wired connection.
18 . An aerial vehicle comprising:
a body including a chassis and a frame affixed to the chassis;
a plurality of rotor assemblies;
a plurality of rotor arms, each rotor arm having a distal end, and a proximal end structurally coupled to the body and a rotor assembly of the plurality of rotor assemblies structurally coupled to the distal end;
an interface configured to receive a flight plan to perform a job using the aerial vehicle, wherein the job comprises an instruction to inspect an area and the flight plan identifies one or more waypoints proximate to or within the area; and
a processing system configured to:
designate ground control points by, for at least one of the one or more waypoints:
navigating the UAV to the waypoint, and
performing, prior to the job, an action to designate the waypoint as a ground control point (GCP) including:
determining a three-dimensional position of the UAV at a time of designating the GCP;
determining an altitude of the UAV relative to a ground surface using one or more sensors;
computing, based on the altitude and imaging geometry of a camera of the UAV, a projected ground coordinate corresponding to the GCP;
wherein the projected ground coordinate defines a geographic location of the GCP using a separate imaging or localization operation distinct from imagery captured during the job; and
perform the job by capturing, using a camera of the UAV, images usable to generate rectified images associated with the inspection of the area based, at least in part, on the projected ground coordinates.
19 . The aerial vehicle of claim 18 , wherein the flight plan includes a speed at which the aerial vehicle is to travel between the waypoints.
20 . The aerial vehicle of claim 18 , wherein the aerial vehicle is equipped with sensors to actively monitor and detect obstructions.
21 . The aerial vehicle of claim 18 , wherein the interface is further configured to:
receive an instruction to modify one or more geographic locations assigned as GCPs, and
recompute the projected ground coordinate for at least one modified GCP based on updated altitude or imaging geometry information.
22 . The aerial vehicle of claim 18 , wherein computing the projected ground coordinate further comprises:
determining an offset between a Global Navigation Satellite System (GNSS) receiver and a center of the camera; and
modifying the projected ground coordinate based on the offset.
23 . The aerial vehicle of claim 18 , wherein the interface is further configured to:
provide the captured images and stored location information to an external photogrammetry system for processing,
wherein the external photogrammetry system uses the projected ground coordinates to generate orthorectified imagery.