Patent Publication Number: US-2023150690-A1

Title: Systems and methods for providing safe landing assistance for a vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. § 119 from Indian Patent Application No. 202111052281, filed on Nov. 15, 2021, the contents of which are incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     Various embodiments of the present disclosure relate generally to landing systems for aerial vehicles and more particularly, to systems and methods for providing safe landing assistance for such vehicles. 
     BACKGROUND 
     The landing phase remains a critical phase for all aerial vehicles, including urban air mobility (UAM) vehicles and vertical takeoff and landing (VTOL) vehicles, due to a variety of challenges (e.g., low visibility conditions, pilot spatial disorientation, landing zone intrusions, high speeds, wind gusts, and communication interference) that may impact a pilot&#39;s ability to safely land. In addition to the above challenges, the landing phase is especially critical for UAM vehicles in urban or similar environments due to constrained landing spaces surrounded by adjacent buildings, populated airspace, the city below, or other obstacles around the landing space. For instance, even the slightest misalignment during a rooftop landing or other similar constrained landing space without sufficient time to correct may result in a variety of consequences. Therefore, in a constrained landing space, such as over a building, the margin of error when landing is limited, which may present challenges for on-board pilots, remote pilots, and/or autonomous aircraft alike. 
     Conventional systems and methods for landing vehicles do not currently provide the precise situational awareness for pilots with varying skillsets, nor do they provide the safety considerations necessary for landing vehicles in constricted urban environments. The present disclosure is directed to overcoming one or more of these above-referenced challenges. 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section. 
     SUMMARY OF THE DISCLOSURE 
     According to certain aspects of the disclosure, systems and methods are disclosed for providing a safe landing for a vehicle. 
     In one embodiment, a method may include: displaying, on one or more displays, a vehicle, an intended landing zone, and a real-time flight path of the vehicle as the vehicle approaches the intended landing zone; receiving, by one or more processors, data related to one or more of the vehicle, the flight path of the vehicle, the intended landing zone, and an obstacle; determining, by the one or more processors, the proximity of the vehicle relative to the center of the intended landing zone based on the received data; causing, by the one or more processors, the one or more displays to display the proximity of the vehicle relative to the center of the intended landing zone; causing, by the one or more processors, the one or more displays to display the obstacle when present; causing, by the one or more processors, the one or more displays to display an alert when the vehicle deviates in proximity to the center of the intended landing zone and/or approaches the obstacle; and upon determining a failure to respond to the alert, by the one or more processors, computing flight controls to modify landing. 
     In another embodiment, a system may include: one or more sensors; one or more databases; a vehicle management system; and one or more displays. The one or more sensors of the system may be executed by one or more processors and configured to: determine one or more obstacles at an intended landing zone of a vehicle and/or along a flight path of the vehicle; determine a position and/or altitude of the vehicle relative to the intended landing zone; and transmit sensor data to one or more display, a vehicle management system, and/or a flight guidance component. The one or more databases of the system may be configured to: transmit data related to one or more of a flight path of the vehicle, an intended landing zone, or obstacles, to one or more displays and a vehicle management system. The vehicle management system may be executed by one or more processors and configured to: receive data from one or more sensors; receive data from one or more databases; process the data received from the one or more sensors with the data received from the one or more databases; and transmit the processed data to a flight guidance component and/or one or more displays. The one or more displays of the system may be executed by one or more processors and configured to: receive data from one or more databases, a vehicle management system, and/or a flight guidance component; and display the received data. 
     In yet another embodiment, a non-transitory computer-readable medium may store instructions that, when executed by a processor, cause the processor to perform a method. The method may include: displaying, on one or more displays, a vehicle, an intended landing zone, and a real-time flight path of the vehicle as the vehicle approaches the intended landing zone; receiving, by one or more processors, data related to one or more of the vehicle, the flight path of the vehicle, the intended landing zone, and an obstacle; determining, by the one or more processors, the proximity of the vehicle relative to the center of the intended landing zone based on the received data; causing, by the one or more processors, the one or more displays to display the proximity of the vehicle relative to the center of the intended landing zone; causing, by the one or more processors, the one or more displays to display the obstacle when present; causing, by the one or more processors, the one or more displays to display an alert when the vehicle deviates in proximity to the center of the intended landing zone and/or approaches the obstacle; and upon determining a failure to respond to the alert, by the one or more processors, computing flight controls to modify landing. 
     Additional objects and advantages of the disclosed embodiments will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the disclosed embodiments. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments. 
         FIG.  1    depicts an example environment in which methods, systems, and other aspects of the present disclosure may be implemented. 
         FIG.  2    depicts an exemplary system for providing safe landing assistance for a vehicle, according to one or more embodiments. 
         FIG.  3    depicts a flowchart of a method for providing safe landing assistance for a vehicle using the system of  FIG.  2   , according to one or more embodiments. 
         FIG.  4    depicts an exemplary display comprising a landing aid generated by the system of  FIG.  2   , according to one or more embodiments. 
         FIG.  5    depicts another exemplary display comprising a landing aid generated by the system of  FIG.  2   , according to one or more embodiments. 
         FIG.  6    depicts a flowchart of a method for monitoring vehicle descent conditions relative to touchdown, according to one or more embodiments. 
         FIG.  7    depicts yet another exemplary display comprising a time/altitude relative to touchdown scale generated by the system of  FIG.  2   , according to one or more embodiments. 
         FIGS.  8 A- 8 B,  9 A- 9 B, and  10 A- 10 B  depict various exemplary landing scenarios of a vehicle as displayed with landing aids generated by the system of  FIG.  2   , according to one or more embodiments. 
         FIG.  11    depicts an example system that may execute techniques presented herein. 
     
    
    
     DETAILED DESCRIPTION 
     In general, the present disclosure is directed to systems and methods for providing a safe landing for a vehicle using an intuitive display of a landing aid and an alert system, and by computing flight controls to modify landing, if necessary. A system of the present disclosure may include one or more displays depicting landing details for a vehicle. The landing details may be displayed with a landing orientation aid and with a time/altitude relative to touchdown scale. The landing orientation aid may depict the proximity of the vehicle relative to the center of the intended landing zone and the time/altitude to touchdown scale may depict the amount of time and/or altitude of the vehicle until it reaches touchdown at the landing zone. Additionally, the time/altitude relative to touchdown scale may indicate an abort point, at which point an alert will be issued to abort the attempted landing. 
     The system may generate the one or more displays by determining the proximity of the vehicle relative to the intended landing zone, the vehicle descent conditions, and landing obstacles based on data processed and received from one or more databases (e.g., Vertiport database, Obstacle database, Nav database) and onboard sensors. The system may process the data received using a vehicle management system and a flight guidance component of the system may further process the data to generate flight guidance for the one or more displays. For instance, a system of the present of the disclosure may depict the orientation of the vehicle relative to the intended landing zone, the presence and/or direction of deviation from the intended landing zone, ways to correct alignment/orientation with the landing zone, the amount of time available for adjusting alignment/orientation with the landing zone, and landing zone obstacles, as well as alerts to indicate when any of these factors impact a safe landing. Furthermore, the system of the present disclosure may also compute flight controls to modify the vehicle landing in situations where there is no response to the alert from the vehicle&#39;s pilot/operator and/or corrective action is too late. 
     In some embodiments, the landing zone or intended landing zone may be an elevated landing port/hub or a building. In some embodiments, the one or more displays may be displayed onboard a vehicle, while in other embodiments the one or more displays may be displayed off-board a vehicle, such as a remote operations ground station. 
     While this disclosure describes the systems and methods with reference to UAM vehicles and VTOL vehicles, it should be appreciated that the present systems and methods are also applicable to management of other types of vehicles, including those of aircraft, drones, automobiles, ships, spacecraft, or any other manned, unmanned, autonomous and/or Internet-connected vehicle. 
       FIG.  1    depicts an example environment in which methods, systems, and other aspects of the present disclosure may be implemented. The environment of  FIG.  1    may include an airspace  100  and one or more hubs  111 - 117 . A hub, such as any one of the one or more hubs  111 - 117 , may be a facility where one or more vehicles  131   a - 133   b  may take off, land, or remain parked (e.g., airport, vertiport, heliport, vertistop, helistop, temporary landing/takeoff facility, or the like). The airspace  100  may accommodate vehicles  131   a - 133   b  of various types  131 - 133  (collectively, “vehicle  131 ” unless indicated otherwise herein), flying at various altitudes and via various routes  141 . A vehicle, such as any one of the vehicles  131   a - 133   b,  may be any apparatus or vehicle of air transportation capable of traveling between two or more hubs  111 - 117 , such as an airplane, a vertical take-off and landing aircraft (VTOL), a drone, a helicopter, an unmanned aerial vehicle (UAV), an urban air mobility (UAM) vehicle, a hot-air balloon, a military aircraft, etc. Any one of the vehicles  131   a - 133   b  may be connected to one another and/or to one or more of the hubs  111 - 117 , over a communication network. As shown in  FIG.  1   , different types of vehicles that share the airspace  100  are illustrated, which are distinguished, by way of example, as model  131  (vehicle  131   a  and vehicle  131   b ), model  132  (vehicle  132   a,  vehicle  132   b,  and vehicle  132   c ), and model  133  (vehicle  133   a  and vehicle  133   b ). 
     As further shown in  FIG.  1   , an airspace  100  may have one or more weather constraints  121 , spatial restrictions  122  (e.g., buildings), and temporary flight restrictions (TFR)  123 . These are exemplary factors that a vehicle management system of a vehicle  131   a - 133   b  may be required to consider and/or analyze in order to derive the most safe and optimal flight trajectory of the vehicle. For example, if a vehicle management system of a vehicle  131   a - 133   b  planning to travel from hub  112  to hub  115  predicts that the vehicle may be affected by an adverse weather condition, such as weather constraint  121 , in the airspace, the vehicle management system may modify a direct path (e.g., the route  141  between hub  112  and hub  115 ) with a slight curvature away from the weather constraint  121  (e.g., a northward detour) to form a deviated route  142 . For instance, the deviated route  142  may ensure that the path and the time of the vehicle (e.g., 4-D coordinates of the flight trajectory) do not intersect any position and time coordinates of the weather constraint  121  (e.g., 4-D coordinates of the weather constraint  121 ). 
     As another example, the vehicle management system of vehicle  131   b  may predict, prior to take-off, that spatial restriction  122 , caused by buildings, would hinder the direct flight path of aircraft  131   b  flying from hub  112  to hub  117 , as depicted in  FIG.  1   . In response to that prediction, the vehicle management system of vehicle  131   b  may generate a 4-D trajectory with a vehicle path that bypasses a 3-dimensional zone (e.g., zone including the location and the altitude) associated with those particular buildings. As yet another example, the vehicle management system of vehicle  133   b  may predict, prior to take-off, that TFR  123 , as well as some potential 4-D trajectories of another vehicle  132   c,  would hinder or conflict with the direct flight path of vehicle  133   b , as depicted in  FIG.  1   . In response, the vehicle management computer of vehicle  133   b  may generate a 4-D trajectory with path and time coordinates that do not intersect either the 4-D coordinates of the TFR  123  or the 4-D trajectory of the other aircraft vehicle  132   c.  In this case, the TFR  123  and collision risk with another vehicle  132   c  are examples of dynamic factors which may or may not be in effect, depending on the scheduled time of travel, the effective times of TFR, and the path and schedule of the other vehicle  132   c.  As described in these examples, the 4-D trajectory derivation process, including any modification or re-negotiation, may be completed prior to take-off of the vehicle. 
     As another example, the vehicle management computer of vehicle  131   b  may determine to use one of the routes  141  that are set aside for vehicle  131   b  to use, either exclusively or non-exclusively. The vehicle  131   b  may generate a 4-D trajectory with a vehicle path that follows one of the routes  141 . 
     As indicated above,  FIG.  1    is provided merely as an example environment of an airspace that includes exemplary types of vehicles, hubs, zones, restrictions, and routes. Regarding particular details of the vehicle, hubs, zones, restrictions, and routes, other examples are possible and may differ from what was described with respect to  FIG.  1   . For example, types of zones and restrictions which may become a factor in trajectory derivation, other than those described above, may include availability of hubs, reserved paths or sky lanes (e.g., routes  141 ), any ground-originating obstacle which extends out to certain levels of altitudes, any known zones of avoidance (e.g., noise sensitive zones), air transport regulations (e.g., closeness to airports), etc. Any factor that renders the 4-D trajectory to be modified from the direct or the shortest path between two hubs may be considered during the derivation process. 
       FIG.  2    depicts an exemplary block diagram of a system  200 , of a vehicle, such as vehicle  131   a - 133   b.  Generally, the block diagram of system  200  may depict system components, information/data, and communications between the system components of a piloted, semi-autonomous, or a fully autonomous vehicle. The vehicle  131  may be one of the piloted, semi-autonomous vehicles, and/or the fully autonomous vehicles. 
     The block diagram of system  200  of vehicle  131  may include electrical, mechanical, and/or software system components (collectively, “vehicle system components”). The vehicle system components may include: position sensors  202 , obstacle detection sensor(s)  204 , radio altimeter  206 , vehicle/flight management system  208 , flight guidance  210 , and flight control system  212 . The vehicle system components may also include pilot/user interface  214 , inceptors  216 , actuators  218 , camera(s)  220 . Also included in block diagram  200  is vertiport database  230 , Navigational (nav) database  240 , obstacle database  250 , and cockpit display system  260 . The vehicle system components may be connected by one or a combination of wired or wireless communication interfaces, such as TCP/IP communication over Wi-Fi or Ethernet (with or without switches), RS-422, ARINC-429, or other communication standards (with or without protocol switches, as needed). 
     The vehicle/flight management system  208  may include at least a network interface, a processor, and a memory, each coupled to each other via a bus or indirectly via wired or wireless connections (e.g., Wi-Fi, Ethernet, parallel or serial ATA, etc.). The memory may store, and the processor may execute, a vehicle management program. The vehicle management program may obtain inputs from other vehicle system components and output instructions/data, in accordance with the program code of the vehicle management program. For instance, the vehicle/flight management system  208  may receive sensor data from position sensors  202 , obstacle detection sensor  204 , and radio altimeter  206 , and camera(s)  220 . Vehicle/flight management system  208  may also receive data from vertiport database  230 , Nav database  240 , and obstacle database  250 . The vehicle/flight management system  208  may process the received data and may transmit instructions/data to cockpit display system  260  and/or flight guidance component  210 . The vehicle/flight management system  208  may also receive data from flight guidance component  210  and/or cockpit display system  260 . 
     The vehicle management program of vehicle/flight management system  208  may include flight routing to determine or receive a planned flight path. The vehicle/flight management system  208  may also be configured to determine landing trajectory. The planned flight path and/or landing trajectory may be determined using various planning algorithms, vehicle constraints (e.g., cruising speed, maximum speed, maximum/minimum altitude, maximum range, etc.) of vehicle  131 , and/or external constraints (e.g., restricted airspace, noise abatement zones, etc.). The planned/received flight path may include a 4-D trajectory of a flight trajectory with 4-D coordinates, a flight path based on waypoints, any suitable flight path for the vehicle  131 , or any combination thereof. The 4-D coordinates may include 3-D coordinates of space (e.g., latitude, longitude, and altitude) for a flight path and time coordinate. 
     The flight routing program of vehicle/flight management system  208  may determine an unplanned flight path based on the planned flight path and unplanned event triggers, and using the various planning algorithms, the vehicle constraints of the vehicle  131 , and/or the external constraints. The vehicle/flight management system  208  may determine the unplanned event triggers based on data/information the vehicle/flight management system  208  receives from other vehicle system components. The unplanned event triggers may include one or a combination of: (1) emergency landing, as indicated by pilot/user interface  214 , flight guidance component  210 , and/or flight control system  212 ; (2) intruder vehicle  131   a - 133   b  encroaching on a safe flight envelope of the vehicle  131 ; (3) weather changes indicated by the route weather information (or updates thereto); (4) the machine vision outputs indicating a portion of the physical environment may be or will be within the safe flight envelope of the vehicle  131 ; and/or (5) the machine vision outputs indicating a landing zone is obstructed. 
     The vehicle/flight management system  208  may determine/compute landing trajectory based on vehicle performance (e.g., speed, altitude, position, time) and data received from vertiport database  230  (e.g., landing point), nav database  240  (e.g., waypoints), and obstacle database  250 . The landing trajectory computed by the vehicle/flight management system  208  may be transmitted to flight guidance  210  and flight control system  212 . 
     Position sensors  202  may include one or more global navigation satellite (GNSS) receivers. The GNSS receivers may receive signals from the United States developed Global Position System (GPS), the Russian developed Global Navigation Satellite System (GLONASS), the European Union developed Galileo system, and/or the Chinese developed BeiDou system, or other global or regional satellite navigation systems. The GNSS receivers may determine positioning information for the vehicle  131 . The positioning information may include information about one or more of position (e.g., latitude and longitude, or Cartesian coordinates), altitude, speed, heading, or track, etc. for the vehicle. The positions sensors  202  may transmit the positioning information to the vehicle/flight management system  208 , the flight guidance component  210 , and/or the flight control system  212 . 
     The obstacle detection sensor  204  may include one or more radar(s), one or more magnetometer(s), an attitude heading reference system (AHRS), light detection and ranging (LIDAR), and/or one or more air data module(s). The one or more radar(s) may be weather radar(s) to scan for weather and/or DAPA radar(s) (either omnidirectional and/or directional) to scan for terrain/ground/objects/obstacles. The one or more radar(s) (collectively “radar systems”) may obtain radar information. The radar information may include information about the local weather and the terrain/ground/objects/obstacles (e.g., other vehicles or obstacles and associated locations/movement). The weather information may include information about precipitation, wind, turbulence, storms, cloud coverage, visibility, etc. of the external environment of the vehicle  131  along/near a flight path, at a destination and/or departure location (e.g., one of the hubs  111 - 117 ), or fora general area around the flight path, destination location, and/or departure location. The one or more magnetometer(s) may measure magnetism to obtain bearing information for the vehicle  131 . The AHRS may include sensors (e.g., three sensors on three axes) to obtain attitude information for the vehicle  131 . The attitude information may include roll, pitch, and yaw of the vehicle  131 . The LIDAR may scan for obstacles and obtain LIDAR information. The air data module(s) may sense external air pressure to obtain airspeed information for the vehicle  131 . The radar information, the bearing information, the attitude information, airspeed information, and/or the positioning information (collectively, obstacle detection information) may be transmitted to the vehicle/flight management system  208 , flight guidance component  210 , and/or flight control system  212 . 
     Radio altimeter  206  may include a radar. The radar may be a low-range radio altimeter (LRRA) to measure the altitude or height of vehicle  131  above terrain/ground immediately below the vehicle. Radio altimeter  206  may obtain altitude information. The altitude information may be transmitted to the vehicle/flight management system  208 , flight guidance component  210 , and/or flight control system  212 . 
     The camera(s)  220  may include inferred or optical cameras, LIDAR, or other visual imaging systems to record internal or external environments of the vehicle  131 . The camera(s)  220  may obtain inferred images; optical images; and/or LIDAR point cloud data, or any combination thereof (collectively “imaging data”). The LIDAR point cloud data may include coordinates (which may include, e.g., location, intensity, time information, etc.) of each data point received by the LIDAR. The camera(s)  220  may include a machine vision function. The machine vision function may process the obtained imaging data to detect objects, locations of the detected objects, speed/velocity (relative and/or absolute) of the detected objects, size and/or shape of the detected objects, etc. (collectively, “machine vision outputs”). For instance, the machine vision function may be used to image a landing zone to confirm the landing zone is clear/unobstructed. Additionally or alternatively, the machine vision function may determine whether physical environment (e.g., buildings, structures, cranes, etc.) around the vehicle  131  and/or on/near the routes  141  may be or will be (e.g., based on location, speed, planned flight path of the vehicle  131 ) within a safe flight envelope of the vehicle  131 . The imaging data and/or the machine vision outputs may be referred to as “imaging output data.” The camera(s)  220  may transmit the imaging data and/or the machine vision outputs of the machine vision function to the vehicle/flight management system  208  and/or cockpit display system  260 . 
     Vertiport database  230  may include hub data. For example, vertiport database  230  may store detailed maps. Hub data may include geographical and/or photographic information about hubs where vehicle  131  may depart/takeoff, land, pass through, or may alternatively travel to or through. Vertiport database  230  may include information about landing zones, landing pads, and runways, including identifiers and coordinates. Vertiport database  230  may transmit hub data to vehicle/flight management system  208  and/or cockpit display system  260 . 
     Nav database  240  may include navigation data stored in nav database  240 . The navigation data may include information related to navigation or routing of a vehicle, such as vehicle  131 , in a geographic area. The navigation data stored in the nav database  240  may also include, for example, waypoints, routes, hubs (e.g., vertiports, airports, runways, landing zones, landing pads) airways, radio navigation aids, holding patterns, building profile data etc. In some embodiments, nav database  240  may include dynamic data such as three-dimensional coordinates for the intended or planned flight path of travel of the vehicle  131 , and alternate paths of travel of the vehicle  131  (e.g., to avoid other vehicles  132 , obstacles, or weather). Nav database  240  may transmit navigation data to vehicle/flight management system  208  and/or cockpit display system  260 . 
     Obstacle database  250  may include obstacle data for an area around vehicle  131  and/or on/near the routes  141  and/or on/near a landing zone. Obstacle database  250  may be maintained by an organization such as the FAA. The obstacle data may include, for example, map data, almanac data, information regarding the dimensions and positions of one or more obstacles, and/or other information that may be relevant to a vehicle that is or will be in the vicinity of one or more obstacles. 
     Obstacle database  250  may transmit obstacle data to vehicle/flight management system  208  and/or cockpit display system  260 . 
     The flight guidance component  210  may receive data from vehicle/flight management system  208 . In some embodiments, flight guidance component  210  may receive sensor data from position sensors  202 , obstacle detection sensor  204 , and/or radio altimeter  206 . Flight guidance component  210  may process/analyze the received data to generate flight guidance data, instructions, and/or commands. Flight guidance component  210  may transmit flight guidance data/instructions to cockpit display system  260  and/or vehicle/flight management system  208 . The flight guidance component  210  may also transmit data/instructions/commands to flight control system  212 . In some embodiments, flight guidance component  210  may update flight guidance based on data which may be received from flight control system  212  and/or cockpit display system  260 . 
     The flight control system  212  may receive flight guidance and/or commands from flight guidance component  210 . The flight control system  212  may receive input from pilot/user interface  214  and inceptors  216  operated by pilot/user interface  214 . Flight control system  212  may also receive sensor data from position sensors  202 , obstacle detection sensor  204 , and/or radio altimeter  206 . The flight control system  212  may also receive data from cockpit display system  260 . In some embodiments, flight control system  212  may transmit data to cockpit display system  260 . 
     The flight control system  212  may execute a flight control program. The flight control program may control the actuators  218  in accordance with the flight guidance data or commands from flight guidance component  210 , the sensor data received from one or more of position sensors  202 , obstacle detection sensor  204 , radio altimeter  206  (e.g., vehicle positioning information), the data received from cockpit display system  260 , and/or user inputs (e.g., of a pilot if aircraft  131  is a piloted or semi-autonomous vehicle) via pilot/user interface  214  and inceptors  216 . The flight control system  212  may receive flight guidance data/commands from flight guidance component  210  and/or the user inputs from pilot/user interface  214  and inceptors  216  (collectively, “course”), and may determine inputs to the actuators  218  to change speed, heading, altitude of the vehicle  131 . 
     The actuators  218  may include: motors, engines, and/or propellers to generate thrust, lift, and/or directional force for the vehicle  131 ; flaps or other surface controls to augment the thrust, lift, and/or directional force for the vehicle  131 ; and/or vehicle mechanical systems (e.g., to deploy landing gear, windshield wiper blades, signal lights, etc.). The flight control system  212  may control the actuators  218  by transmitting instructions, in accordance with a flight control program. 
     The cockpit display system  260  may receive data from and/or transmit data to vehicle/flight management system  208 , flight guidance component  210  and/or flight control system  212 . The cockpit display system  260  may also receive data from vertiport database  230 , nav database  240 , and/or obstacle database  250 . Cockpit display system may generate one or more displays based on the received data. The one or more displays include display  270 , display  280 , and/or display  290 . A more detailed description of display  280  is provided further below in reference to  FIG.  4    and a more detailed description of display  270  and display  290  are provided further below in reference to  FIGS.  5  and  7   , respectively. While the block diagram of system  200  of vehicle  131  depicts the one or more displays ( 270 ,  280 , and  290 ) as part of cockpit display system  260  (i.e. onboard the vehicle  131 ), in at least one embodiment, the one or more displays may display off-board the vehicle  131 , such as a remote operations ground station. In some embodiments, all three displays may be viewed at the same time. In other embodiments, only one display or a combination of two of displays may be viewed. It is understood that the one or more displays may include any number of displays and may display any one of the displays  270 ,  280 ,  290 , or combinations thereof. The one or more displays may also include any system or device capable of conveying data related to a vehicle (e.g., vehicle  131 ) onboard the vehicle, off board the vehicle, or combinations thereof. 
     System  200  provides landing assistance to vehicle  131 , as detailed further below. 
       FIG.  3    depicts an exemplary flowchart of a method  300  for providing safe landing assistance to a vehicle, such as vehicle  131 , according to one or more embodiments. 
     Step  302  may include displaying, on one or more displays, a vehicle, an intended landing zone, and a real-time flight path of the vehicle as the vehicle approaches the intended landing zone. In one aspect of the present disclosure, in step  302 , the one or more displays of cockpit display system  260 , display  270 , display  280 , and/or display  290  may display vehicle  131 . The one or more displays may also display an intended landing zone, and a real-time flight path of the vehicle  131  as the vehicle  131  approaches the intended landing zone. In some embodiments, the display is generated from data received by cockpit display system  260  from vehicle/flight management system  208 , camera(s)  220 , nav database  240 , and/or vertiport database  230 . 
     Step  304  may include receiving data related to one or more of the vehicle, the flight path of the vehicle, the intended landing zone, and an obstacle. Data related to one or more of the vehicle, the flight path of the vehicle, the intended landing zone, and an obstacle may be received by vehicle/flight management system  208 . For instance, the data received by vehicle/flight management system  208  may be transmitted from one or more of position sensors  202 , obstacle detection sensor  204 , radio altimeter  206 , camera(s)  220 , vertiport database  230 , nav database  240 , and obstacle database  250 . In some examples, vehicle/flight management system  208  may receive data from cockpit display system  260  via a graphical user interface. 
     The data related to vehicle  131  may include sensor data and the sensor data may include positioning and/or orientation information. The positioning and/or orientation information may include information about one or more of the position, altitude, speed, and/or track for the vehicle  131 . The data related to the flight path of vehicle  131  may include navigation data and a planned flight path of vehicle  131 . Data related to the intended landing zone may include hub data (e.g., landing zone identifiers and coordinates), obstacle data, and navigation data (e.g., landing zone information, building profile data etc.) for the intended landing zone. Data related to an obstacle may include obstacle data such as map data and information regarding the dimensions and positions of one or more obstacles. 
     Step  306  may include determining the proximity of the vehicle relative to the center of the intended landing zone based on the received data (from step  304 ). For example, the vehicle/flight management system  208  may determine the proximity of the vehicle  131  relative to the center of the intended landing zone based on data related to the vehicle  131 , the flight path of the vehicle  131 , the intended landing zone, an obstacle, and combinations thereof, and received from one or more of position sensors  202 , obstacle detection sensor  204 , radio altimeter  206 , camera(s)  220 , vertiport database  230 , nav database  240 , and obstacle database  250 . 
     Determining the proximity of the vehicle relative to the center of the intended landing zone may include receiving from the onboard system components, positioning and/or orientation information such as bearing information, the attitude information, the airspeed information, and/or the positioning information of the navigation data to indicate the position (e.g., GPS coordinate), altitude, orientation, speed (descent rate and/or other speed vector components), airspeed, and/or bearing of the vehicle  131 . Determining the proximity of the vehicle relative to the center of the intended landing zone may further include analyzing the positioning and/or orientation information of the vehicle (e.g., vehicle  131 ) with the positional data (e.g. GPS coordinates) of the intended landing zone to determine one or a combination of: (1) distance from the intended landing zone; (2) a relative orientation from the intended landing zone; and/or (3) a position and/or altitude with respect to the intended landing zone. In one aspect, the positional data of the intended landing zone may be further analyzed with the positioning and/or orientation information of the vehicle to determine the relative orientation from the center of the intended landing zone and/or a position with respect to the center of the intended landing zone. 
     In some embodiments, the step of determining the proximity of the vehicle relative to the center of the intended landing zone may also include determining or computing the landing trajectory based on data related to one or more of the vehicle (e.g., vehicle performance, speed, altitude), the flight path of the vehicle, the intended landing zone, and an obstacle. Further, in at least one embodiment, the method of  300 , may determine the proximity of the vehicle relative to any location within the intended landing zone, including but not limited to the center, based on the computed landing trajectory. 
     Step  308  may include causing the one or more displays to display the proximity of the vehicle relative to the center of the intended landing zone. For example, vehicle/flight management system  208  may cause display  270  and/or display  280  to display the proximity of vehicle  131  relative to the center of the intended landing zone 
     Display  270  and/or display  280  may display the distance of vehicle  131  from the intended landing zone, the relative orientation of vehicle  131  from the intended landing zone and/or the position of vehicle  131  with respect to the intended landing zone, as detailed further below. In some embodiments, the proximity of the vehicle relative to the center of the intended landing zone may be displayed on the one or more displays, such as display  270  and/or display  280 , by a landing aid symbol surrounding the intended landing zone. Dimensions of the landing aid symbol displayed may change (e.g., increase or decrease) relative to the distance of the vehicle from the intended landing zone. Further, display  290  may display the altitude of vehicle  131  with respect to the intended landing zone. 
     Step  310  may include causing the one or more displays to display the obstacle when present. In some examples, an obstacle may include one or more of another vehicle at or near the intended landing zone, a person at or near the intended landing zone, or a weather condition at or near the intended landing zone. Prior to causing the one or more displays to display an obstacle, vehicle/flight management system  208  may analyze data received from obstacle detection sensor  204 , camera(s)  220 , and obstacle database  250 , as well as other system components to detect the presence of one or more obstacles. The LIDAR component of obstacle detection sensor  204  and/or camera(s)  220  may scan and map the intended landing zone area for obstacles. In some embodiments, camera(s)  220  may use a machine vision function to analyze the imaging data obtained. For instance, camera(s)  220  may obtain imaging data as vehicle  131  approaches the intended landing zone and the imaging data may be analyzed to detect obstacles at or near the intended landing zone. The imaging data and/or the machine vision outputs may be transmitted to the cockpit display system  260  for display on the one or more displays. 
     Step  312  may include causing the one or more displays to display an alert when the vehicle deviates in proximity to the center of the intended landing zone and/or approaches the obstacle. Step  314  may be performed when a failure to respond to the alert of claim  312  is determined. In step  314 , flight controls may be computed to modify landing. In one aspect of the present disclosure, once the proximity of the vehicle relative to the center of the intended landing zone is determined (step  306 ) and said proximity is displayed on the one or more displays (step  308 ), the proximity of the vehicle relative to the center of the intended landing zone will continue to be monitored as the vehicle descends. For instance, the one or more displays may display a landing aid symbol surrounding the intended landing zone, as detailed further below. The landing aid symbol may capture the positioning/orientation of the vehicle relative to the center of the intended landing zone and may provide a visual to indicate correct orientation of the vehicle or incorrect orientation of the vehicle relative to the center of the intended landing zone. In some examples, the landing aid symbol may display one or more colors based on the proximity of the vehicle to the center of the intended landing zone. 
     In some embodiments, flight guidance component  210  may determine that the deviation of the vehicle from center of the intended landing zone and/or the orientation of the vehicle relative to the center of the intended landing zone is either beyond the point of correction for a safe landing or close to reaching this point. As a result, an alert may be generated and the one or more displays may display the alert. The alert may display as a warning or the alert may indicate that the vehicle should “GO AROUND” or “ABORT LANDING”. The alert may be visual. The alert may also be auditory. 
     In some embodiments, the vehicle system may determine that the vehicle is approaching the obstacle previously detected and displayed in step  308 , during the landing phase. As the vehicle approaches the obstacle, an alert may be generated. For instance, if a person is detected as being at or near the intended landing zone and the vehicle is approaching said person, an alert may be generated on the one or more displays. 
     The alert may be generated as an instruction/warning to the pilot or remote pilot to abort the intended landing due to the presence of an obstacle and/or incorrect vehicle orientation, by going around the intended landing zone and re-attempting the landing. For instance, a pilot may want to leave the intended landing zone and return to re-attempt landing after an obstacle (e.g., another vehicle, person) is no longer present/detected. A pilot may also want to leave the intended landing zone and return to have more time to correct and/or adjust the orientation of the vehicle for a safe landing. In some examples, the vehicle may go around the intended landing zone and proceed to another landing zone. 
     In one aspect, the method may determine that the vehicle does not respond to the alert. A failure to respond to the alert means that the vehicle is continuing to approach the intended landing zone after the landing has been determined to be unsafe. When the landing is unsafe, the deviation of the vehicle in proximity to the center of the landing zone may not be able to be corrected before touchdown or an obstacle may be present at or near the intended landing zone. In step  314 , when a failure to respond to the alert is determined, flight controls may be computed to modify the landing. Modifying landing may include performing a maneuver to a holding area or alternative landing zone. For instance, flight guidance component  210  may transmit instructions or commands to flight control system  212 . Flight control system  212  may control actuators  218  to modify the landing by causing vehicle  131  to go around the intended landing zone and move to a holding area or an alternative landing zone. 
     In some embodiments where an obstacle is detected, flight guidance component  210  may transmit a command to flight control system  212  to perform an emergency procedure by modify the landing and causing the vehicle  131  to ascend, divert, or hover to avoid the obstacle. In these embodiments, the emergency procedure command may be triggered by pilot request, cockpit display system  260 , or obstacle detection sensor  204 . In addition, after vehicle  131  reaches a safe position due to the modified landing caused by flight guidance component  210  and flight control system  212 , the flight guidance component  210  and flight control system  212  may automatically disengage, allowing the pilot or remote pilot to regain control. 
     Further, modifying the landing may include reducing or decreasing the rate of descent of the vehicle to allow for a safe landing. In some embodiments, it may be determined that there is only a slight deviation of the vehicle from the center of the intended landing that may be corrected if the rate of descent of the vehicle is reduced. In these embodiments, the flight control system  212  may control actuators  218  to decrease the descent rate. 
       FIG.  4    depicts an exemplary display comprising a landing aid, according to one or more embodiments. More particularly,  FIG.  4    depicts display  280  of system  200  described above with respect to  FIG.  2   . For instance, cockpit display system  260  may display the display  280 . Display  280  may be referred to as a vertiport moving map, as it depicts a hub (e.g., vertiport) as vehicle  131  approaches the hub. Display  280  may depict airspace  100  described above with respect to  FIG.  1   . 
     Display  280  may serve as a moving map that displays a lateral profile of intended landing zone  402  and the flight path of vehicle  131  through airspace  100  as vehicle  131  approaches the intended landing zone  402 . Display  280  displays hub  111  and nearby hubs  112  and  113  as well as vehicles  132 , which share airspace  100  with vehicle  131 . Each of hubs  111 - 113  may be building rooftops or elevated landing ports. Display  280  depicts an intended landing zone  402 , located on top of hub  111  (e.g., a building). For instance, display  280  may show when vehicles other than vehicle  131  approach hub  111 . 
     Landing aid symbol  406  may be generated around intended landing zone  402  and may generally correspond to a shape of the intended landing zone  402 . For example, landing aid symbol  406  may be depicted as a circle that forms a ring around intended landing zone  402 . However, it is understood that landing aid symbol  406  may be depicted as any shape as desired, and may be displayed in any location on the one or more displays. 
     Landing aid symbol  406  encompasses landing zone center  404 , which corresponds to the center of intended landing zone  402 . Landing aid symbol  406  also includes heading  408  and landing aid crosshair  410 . Heading  408  may represent the compass direction in which the nose of vehicle  131  is directed. Display  280  may also depict landing deviation  414 , which may be shown on landing aid symbol  406 . Landing deviation  414  may depict the magnitude/amount of deviation and the direction of deviation of vehicle  131  from landing zone center  404 . Display  280  may also depict alignment indicator  418 . Alignment indicator  418  may be shown on landing aid symbol  406 . Alignment indicator  418  may depict the magnitude/amount and/or the direction of correct alignment of vehicle  131  with landing zone center  404 . Also depicted on display  280  is wind speed  416  and vehicle crosshair  412  on vehicle  131 . 
     Landing aid symbol  406  may provide a visual representation of the proximity of vehicle  131  to landing zone center  404  of the intended landing zone  402 . In order to achieve a safe landing vehicle crosshair  412  depicted on vehicle  131  should align with the landing aid crosshair  410 . In some embodiments, the vehicle crosshair  412  may be configured to display an indicator to indicate alignment with the landing aid crosshair  410 . The indicator may include any type of indicator for indicating alignment with the landing aid crosshair  410 , such as, for example, a color, a highlight, a symbol, or any other indicator. For instance, when the vehicle crosshair  412  aligns with the landing aid crosshair  410 , the vehicle crosshair  412  may display a green color. When the vehicle crosshair  412  is not aligned with the landing aid crosshair  410 , the vehicle crosshair  412  may display a white color. Other indicators may also be used for vehicle crosshair  412  to distinguish between crosshair alignment and misalignment. 
     Landing aid symbol  406 , which may be a circle, may display one or more indicators (e.g., colors) along the circumference of the circle. In some embodiments, a first indicator may indicate a correct orientation of the vehicle  131  for safe landing and a second indicator may indicate deviation of the vehicle  131  from the landing zone center  404  of the intended landing zone  402 . In some embodiments, the second indicator displayed along the circumference of the circle may increase as the amount of deviation of the vehicle from the center of the intended landing zone increases and an amount of the first indicator displayed along the circumference of the circle may increase as the vehicle aligns with the center of the intended landing zone. For example, the first indicator may include a first color and the second indicator may include a second color. A shading of the first color may darken or otherwise become more pronounced as the vehicle aligns with the center of the intended landing zone. Similarly, a shading of the second color may darken or otherwise become more pronounced as the amount of deviation of the vehicle from the center of the intended landing zone increases. 
     Further, in some embodiments, the second color may be displayed toward the direction of deviation of the vehicle from the center of the intended landing zone. For instance, display  280  of  FIG.  4    shows that vehicle  131  is not completely aligned with landing zone center  404 . The vehicle crosshair  412  does not align with the landing aid cross hair  410 . Furthermore, display  280  displays a slight deviation in proximity of vehicle  131  to landing zone center  404 . 
     In  FIG.  4    vehicle  131  deviates from the landing zone center  404  and landing deviation  414  indicates the degree and the direction of deviation. For example, a first color is shown around more than half the circumference of landing aid symbol  406  at alignment indicator  418 , while a second color is shown at landing deviation  414 . Landing deviation  414  represents the amount of deviation from landing zone center  404  and the direction of deviation. Vehicle  131  deviates to the right of landing zone center  404  and landing aid crosshair  410  in the direction of landing deviation  414 . As vehicle crosshair  412  becomes more aligned with landing aid cross hair  410 , landing deviation  414 , and the second color thereon will disappear. When vehicle crosshair  412  completely aligns with landing aid crosshair  410 , a color, or other indicator, representing a correct orientation of vehicle  131  will be displayed along the entire circumference of landing aid symbol  406  at alignment indicator  418 . 
     To the contrary, when vehicle crosshair  412  is completely misaligned with landing aid crosshair  410 , a color, or other indicator, indicating deviation of the vehicle  131  from the landing zone center  404  will be displayed along the entire circumference of landing aid symbol  406  at landing deviation  414 . In the example of  FIG.  4   , landing aid symbol  406  may display various combinations in color difference between a first color representing correct orientation of vehicle  131  at alignment indicator  418  and a second color indicating deviation of vehicle  131  at landing deviation  414 , as the orientation of the vehicle  131  is adjusted either toward landing zone center  404  and landing aid crosshair  410  or away from landing zone center  404  and landing aid crosshair  410 . For instance, the amount of the second color displayed at landing deviation  414  will increase along the circumference of landing aid symbol  406  as vehicle  131  deviates farther from landing zone center  404 . 
     Further, factors such as wind speed  416  (and direction) may impact the deviation and/or direction of deviation of vehicle  131  from landing zone center  404 . Landing aid symbol  406  provides a pilot or a remote pilot guidance with respect to adjusting orientation of vehicle  131  during the landing phase. Heading  408  may also be referenced in extreme weather conditions (e.g., high winds) along with landing aid symbol  406  during the landing phase, in order to better align the physical orientation of vehicle  131  with landing zone center  404 . In some instances where there is significant amount of deviation from landing zone center  404 , more adjustments may be required. In other instances where there is very little deviation from landing zone center  404 , only minor adjustments may be required and the vehicle  131  may continue in descent toward touchdown, in the absence of obstacles at the intended landing zone  402 . 
     In one aspect, the size of the landing aid symbol may vary based on the altitude or height of the vehicle above the landing zone, indicating the scope for correcting deviation. For instance, the circumference of landing aid symbol  406  may decrease as the vehicle  131  descends closer to the intended landing zone  402  and the altitude of vehicle  131  decreases. A larger circumference of landing aid symbol  406  corresponds to vehicle  131  having more opportunities to adjust and/or correct alignment with landing aid crosshair  410  and landing zone center  404  prior to landing. The circumference of the landing aid symbol  406  at the hover point (i.e., the start of the vertical landing) may be large enough to provide scope for the vehicle  131  to align with landing aid crosshair  410  and landing zone center  404 , but shrinks as vehicle  131  descends closer to the ground and/or the landing zone. Further, in some embodiments, the size of the landing aid at the hover point may correspond to the size of the actual vehicle. In other words, smaller landing aid symbols may be used for smaller vehicles and larger landing aid symbols may be used for larger vehicles. 
     In some aspects of the present disclosure, the size of the landing aid symbol may be computed dynamically based on a plurality of parameters. Parameters used in determining the size or dimensions of the landing aid symbol may include vehicle performance under various circumstances (e.g., different speeds, weights, air temperatures, pressures, and densities), vehicle maneuverability, and associated contextual data, such as weather and/or wind conditions. For example, the size or dimensions of the landing aid symbol may decrease as poor weather conditions deteriorate and may increase as weather conditions worsen. 
     While  FIG.  4    depicts landing aid symbol  406  as a circle, the landing aid symbol of the present disclosure may be represented by other geometric shapes. In some examples, a color, such as a first color displayed at alignment indicator  418 , indicating correct orientation of vehicle  131  may be green. A color, such as a second color displayed at landing deviation  414 , indicating deviation of vehicle  131  may be red. However, other colors and/or indicators to indicate correct orientation of vehicle  131  and deviation of vehicle  131 , respectively, are envisioned. 
       FIG.  5    depicts another exemplary display comprising a landing aid, according to one or more embodiments. More particularly,  FIG.  5    depicts display  270  of system  200  described above with respect to  FIG.  2   . For instance, cockpit display system  260  may display the display  270 . 
     As shown in  FIG.  5   , display  270  displays the display  280  as discussed above with respect to  FIG.  4    on a horizontal situation indicator (HSI). Display  270  depicts the critical flight information for vehicle  131  (e.g., airspeed, altitude, heading, attitude, and vertical speed) in the same display as display  280 . Display  280  may be embedded in display  270 , so as to increase situational awareness and to facilitate faster pilot decision making during the critical landing phase. 
     Whether or not a vehicle may safely land may also depend on the vehicle&#39;s rate of descent or vertical speed during the landing phase. Even if the landing aid, such as landing aid symbol  406 , provides guidance for adjusting the orientation of a vehicle with respect to the center of the intended landing zone, if the vehicle is descending too quickly, the vehicle may not have enough time to correct or adjust the orientation before reaching the landing zone. 
     Thus,  FIG.  6    depicts a flowchart for a method  600  for monitoring vehicle descent conditions relative to touchdown, according to one or more embodiments. For instance, method  600  may be used to monitor the descent of vehicle  131  as the vehicle  131  approaches landing or touchdown at the intended landing zone  402 . 
     In step  602 , a vertical speed of the vehicle as the vehicle descends during the landing phase may be determined. In some embodiments, the radar signals from the radar(s) of vehicle system  200  may be used to determine the vertical speed of the vehicle  131 . For instance, the vertical speed or descent rate (e.g., a time derivative of the altitude) may be determined by data received by vehicle/flight management system  208  from one or more of position sensors  202 , the radar from obstacle detection sensor  204 , and radio altimeter  206 . 
     Step  604  may include causing the one or more displays to display a scale comprising time and/or altitude intervals relative to a touchdown of the vehicle at the intended landing zone and a vehicle symbol representing the vehicle adjacent to the scale. The scale may also include an abort point indicated between the intervals on the scale. 
     Step  606  may involve causing the one or more displays to display the vehicle symbol moving relative to the scale in a vertical direction, as the vehicle descends towards the intended landing zone. Further, in step  608 , the method may include causing the one or more displays to display an alert when the vehicle symbol reaches the abort point on the scale. 
     In one aspect of the present disclosure, the abort point represents a point on the time/altitude to touchdown scale, until which the vehicle may continue descent toward the intended landing zone while adjusting orientation of the vehicle relative to the center of the intended landing zone. For the purposes of the present disclosure, the abort point may be the point at which a pilot must make a decision on whether to abort the landing and to execute a missed approach maneuver. The abort point may be based on the given flight conditions and may indicate the point at which it is no longer possible for a landing to be completed, while satisfying all safe landing criteria. In other words, after the abort point on the scale is reached, there is insufficient time to adjust the orientation of the vehicle and still achieve a safe landing. If the vehicle  131  is not oriented with the center of the intended landing zone by the time the vehicle symbol reaches the abort point on the scale, then an alert to “GO-AROUND” is generated and displayed. The abort point may be calculated based on the horizontal deviation of vehicle  131  and the height above the ground (e.g., landing zone), which determines the scope for correcting deviation. If it is determined that there is not enough height between vehicle  131  and the intended landing zone for vehicle  131  to align with the landing zone center, then the system may alert vehicle  131  to abort the landing and to execute a missed approach maneuver. In some embodiments, the abort point may also take into account parameters such as vehicle weight, vehicle flight state (e.g. position, orientation, vertical speed), vehicle performance, vehicle maneuverability, external factors (e.g., weather, outside air temperature, visibility), and landing altitude. 
     In some embodiments, the steps of method  600  may be performed concurrently with some of the steps of method  300 . For instance, when the proximity of the vehicle relative to the center of the intended landing zone is determined in step  306 , the vertical speed of the vehicle may be determined as specified in step  602 . When the one or more displays display the proximity of the vehicle relative to the center of the intended landing zone and any obstacles present in steps  308  and  310 , the one or more displays may display the time/altitude to touchdown scale and the vehicle symbol moving relative to the scale in a vertical direction in steps  604  and  606 . 
     Causing the one or more displays to display an alert when the vehicle symbol reaches the abort point on the scale in step  608  of method  600  may also cause the display of the alert when the vehicle deviates in proximity to the center of the intended landing zone in step  312  of method  300 . For instance, the display of the alert in step  608  may be triggered by the vehicle being beyond the point of an orientation adjustment for aligning with the center of the intended landing zone before touchdown. Thus, step  608  may correlate with the vehicle deviating in proximity to the center of the intended landing zone and causing the one or more displays to display an alert in step  312 . Once an alert is displayed as a result of the vehicle symbol reaching the abort point on the scale in step  608 , if it is determined that there is no response to the alert, flight controls may be computed to modify the landing. 
     In the method  600 , the vehicle symbol displayed adjacent to the time/altitude to touchdown scale may also display an indicator, such as a color. The color displayed on the vehicle symbol may correspond to a color designated based on the vertical speed determined for the vehicle. In some embodiments, a first indicator, such as a green color, indicates that the vertical speed of the vehicle is optimal. When the vehicle symbol displays a first indicator (e.g., green color) as the vehicle symbol descends down the time/altitude to touchdown scale and approaches the abort point, this correlates with an acceptable speed (e.g. vertical speed is within a nominal range) that is suitable for adjusting the orientation of the vehicle in time for landing touchdown. 
     In some embodiments, a second indicator, such as an amber color, indicates that there is an increase in vertical speed. An increase in vertical speed may indicate that the vehicle symbol may reach the abort point on the scale sooner. Thus, there may be less time to correct the deviation of the vehicle before the abort point. When the vehicle symbol displays a second indicator (e.g., an amber color), this may prompt the pilot or remote pilot to decrease the speed of the vehicle. Further, in some embodiments, a third indicator, such as a red color indicates that the vertical speed is beyond tolerance. A third indicator (e.g., red color) may display on the vehicle symbol when the vehicle descends at a rate where any deviation from the center of the intended landing zone cannot be corrected or the abort point has been reached on the time/altitude to touchdown scale and deviation still exists. While different colors are described herein, it is understood that the indicator may include any type of indicator, such as, for example, a color, a highlight, a symbol, or any other type of indicator, or combinations thereof, for indicating a speed tolerance of the vehicle with respect to the abort point. 
       FIG.  7    depicts an exemplary display comprising a time/altitude relative to touchdown scale, according to one or more embodiments. More particularly,  FIG.  7    depicts display  290  of system  200  described above with respect to  FIG.  2   . For instance, cockpit display system  260  may display the display  290 . Display  290  may depict airspace  100  described above with respect to  FIG.  1   . 
     Display  290  may display a vertical or profile view of vehicle  131 , symbolized with vehicle symbol  702 , as it approaches an intended landing zone at hub  111 . Hub  111  is depicted as a building, surrounded by other buildings. Vehicle symbol  702  is shown adjacent to time/altitude relative to touchdown scale  704 . The scale includes intervals denoting the amount of time (e.g., seconds) and/or altitude (e.g., feet) from touchdown at the intended landing zone. Therefore, the scale represents time and/or altitude for a vehicle relative to touchdown  708 . The scale may be based on the altitude of vehicle  131  determined at the hover point of vehicle  131  above the intended landing zone or at the start of the descent toward the intended landing zone. For example, the scale may be determined based on the physical height of vehicle  131  from the intended landing zone (e.g. vertiport). In the examples of  FIGS.  7  and  8 A- 10 B , the scale  704  is represented as a time remaining until touchdown. Time/altitude relative to touchdown scale  704  also contains an abort point  706 , determined as detailed above, and indicated as an interval on the scale. 
     Display  290  may display vehicle symbol  702  moving in a vertical direction relative to time/altitude relative to touchdown scale  704 , as vehicle  131  descends toward the intended landing zone at hub  111 . Landing trajectory  710 , which is depicted as a vertical line between the last waypoint represented by the star symbol above the hover point of vehicle symbol  702  and touchdown  708 , may represent the landing trajectory for vehicle  131  as computed by the vehicle/flight management system  208 . In some embodiments, the intended landing zone may be highlighted, such as with a color, to display the intended landing zone area (e.g., hub  111 ). 
     Display  290  of  FIG.  7    depicts an embodiment where vehicle symbol  702  has not reached abort point  706  on time/altitude relative to touchdown scale  704 .  FIG.  7    also demonstrates that vehicle symbol  702  may display a color based on the vertical speed determined for vehicle  131  relative to abort point  706 . For instance, vehicle symbol  702  may display a color that indicates that the vertical speed of vehicle  131  is optimal as vehicle symbol  702  descends time/altitude relative to touchdown scale  704  and approaches the abort  706 . 
       FIGS.  8 A and  8 B  depict exemplary landing scenarios as displayed with landing aids, according to one or more embodiments.  FIG.  8 A  depicts landing scenario  800 A, while  FIG.  8 B  depicts landing scenario  800 B. Each of landing scenarios  800 A and  800 B represent a display of landing aid symbol  406  of display  280  and a time/altitude relative to touchdown scale  704  of display  290 , which may be viewed together and used to assist a pilot or a remote pilot in the landing phase, according to aspects of the present disclosure. 
     Landing scenario  800 A depicts the use of the landing aids according to the present disclosure. Landing scenario  800 A may depict a scenario where the orientation of vehicle  131  is properly aligned with the center of the intended landing zone and configured for a safe landing. For instance, landing scenario  800 A shows that the vehicle crosshair  412  is perfectly aligned with the landing aid crosshair at the landing zone center  404  of intended landing zone  402 . In this scenario, vehicle crosshair  412  displays a color, such as green (e.g., depicted as a light shading in  FIG.  8 A ), to indicate alignment with landing aid crosshair  410 , at alignment indicator  418 . Furthermore,  800 A demonstrates that landing aid symbol  406 , displays the same color (e.g., green) around the entire circumference of landing aid symbol  406  at alignment indicator  418 . The uniform color suggests that there is no deviation of vehicle  131 . Landing scenario  800 A also depicts that vehicle symbol  702  has not reached the abort point  706  on the time/altitude relative to touchdown scale  704 . 
     Landing scenario  800 B depicts the use of the landing aids according to the present disclosure. Landing scenario  800 B may depict a scenario where there is significant deviation of vehicle  131  in proximity to the landing zone center  404  of the intended landing zone  402 . In  800 B vehicle  131  is completely outside of landing aid symbol  406 . Therefore, landing aid symbol  406  displays landing deviation  414 . Furthermore, landing scenario  800 B demonstrates that landing aid symbol  406 , displays the same color (e.g., red) around the entire circumference of landing aid symbol  406 , which corresponds to landing deviation  414 . Landing scenario  800 B also depicts that vehicle symbol  702  has not reached the abort point  706  on the time/altitude relative to touchdown scale  704 . Further, vehicle symbol  702  displays a color (e.g., green) to indicate that the vertical speed of vehicle  131  is optimal. 
       FIGS.  9 A and  9 B  depict exemplary landing scenarios as displayed with landing aids, according to one or more embodiments.  FIG.  9 A  depicts landing scenario  900 A, while  FIG.  9 B  depicts landing scenario  900 B. Each of landing scenarios  900 A and  900 B represent a display of landing aid symbol  406  of display  280  and a time/altitude relative to touchdown scale  704  of display  290 , which may be viewed together and used to assist a pilot or a remote pilot in the landing phase, according to aspects of the present disclosure. 
     Landing scenario  900 A depicts the use of the landing aids according to the present disclosure. Landing scenario  900 A may depict a scenario where there is a slight deviation of vehicle  131  in proximity to landing zone center  404 . For instance, in landing scenario  900 A vehicle crosshair  412  does not align with landing aid crosshair  410 . Landing aid symbol  406  displays two different colors. Further, landing deviation  414  is also depicted on landing aid symbol  406 , displaying a color that indicates deviation. The location of landing deviation  414  also corresponds to the direction of deviation of vehicle  131  (e.g., to the right of the landing zone center  404 ). Alignment indicator  418  is depicted on landing aid symbol  406 , displaying a color that indicates alignment. The color depicted at alignment indicator  418 , increases as vehicle crosshair  412  of vehicle  131  aligns with landing aid crosshair  410  at landing zone center  404 . 
     Landing scenario  900 A also depicts that vehicle symbol  702  has not reached the abort point  706  on the time/altitude relative to touchdown scale  704 . Further, vehicle symbol  702  displays a color (e.g., green) to indicate that the vertical speed of vehicle  131  is optimal. Therefore, landing scenario  900 A suggests that a pilot or a remote pilot has sufficient time to adjust the orientation and correct the slight deviation of vehicle  131  to be in alignment with landing zone center  404  for a safe landing. Once alignment is reached, landing deviation  414  will disappear and the color around landing aid symbol  406  will be uniform, indicating a correct orientation. 
     Landing scenario  900 B depicts the use of the landing aids according to the present disclosure. Landing scenario  900 B may depict a scenario where there is a deviation of vehicle  131  in proximity to landing zone center  404 . For instance, in landing scenario  900 B vehicle crosshair  412  does not align with landing aid crosshair  410 . Landing scenario  900 B also depicts that there is a wingspan difference between vehicle crosshair  412  and landing aid crosshair  410 . Landing aid symbol  406  displays two different colors (e.g., depicted as two different shades in  FIG.  9 B ). Further, landing deviation  414  is also depicted on landing aid symbol  406 , displaying a color that indicates deviation. The location of landing deviation  414  also corresponds to the direction of deviation of vehicle  131  (e.g., to the right of the landing zone center  404 ). Alignment indicator  418  is depicted on landing aid symbol  406 , displaying a color that indicates alignment. The color depicted at alignment indicator  418 , increases as vehicle crosshair  412  of vehicle  131  aligns with landing aid crosshair  410  at landing zone center  404 . 
     Landing scenario  900 B also depicts that vehicle symbol  702  has already reached the abort point  706  on the time/altitude relative to touchdown scale  704 , and has moved beyond the abort point  706 . Further, vehicle symbol  702  displays a color (e.g., red) to indicate that the vertical speed of vehicle  131  is beyond tolerance. Therefore, landing scenario  900 B suggests that a warning will be displayed or output, since vehicle  131  is not in alignment with landing zone center  404  and the vehicle  131  has reached a point where the orientation can no longer be adjusted as indicated by the time/altitude relative to touchdown scale  704  and vehicle symbol  702 . 
       FIGS.  10 A and  10 B  depict exemplary landing scenarios as displayed with landing aids, according to one or more embodiments.  FIG.  10 A  depicts landing scenario  1000 A, while  FIG.  10 B  depicts landing scenario  1000 B. Each of landing scenarios  1000 A and  1000 B represent a display of landing aid symbol  406  of display  280  and a time/altitude relative to touchdown scale  704  of display  290 , which may be viewed together and used to assist a pilot or a remote pilot in the landing phase, according to aspects of the present disclosure. 
     Landing scenario  1000 A depicts the use of the landing aids according to the present disclosure. Landing scenario  1000 A may depict a scenario where there is significant deviation of vehicle  131  in proximity to landing zone center  404 . For instance, in landing scenario  1000 A vehicle crosshair  412  does not align with landing aid crosshair  410 . Landing scenario  1000 A also depicts that there is nearly twice a wingspan difference between vehicle crosshair  412  and landing aid crosshair  410 . In this scenario, vehicle crosshair  412  is also slightly above the location of landing aid crosshair  410 . Landing aid symbol  406  displays two different colors. Further, landing deviation  414  is also depicted on landing aid symbol  406 , displaying a color that indicates deviation and alignment indicator  418  is depicted on landing aid symbol  406 , displaying a color that indicates alignment. The location of landing deviation  414  also corresponds to the direction of deviation of vehicle  131  (e.g., to the right of the landing zone center  404 ). Landing scenario  1000 A shows that half of vehicle  131  is inside of landing aid symbol  406  and that half of vehicle  131  is outside of landing aid symbol  406 , corresponding to alignment indicator  418  and landing deviation  414 , respectively. 
     Landing scenario  1000 A also depicts that vehicle symbol  702  has not reached the abort point  706  on the time/altitude relative to touchdown scale  704 . Further, vehicle symbol  702  displays a color (e.g., yellow or amber) to indicate that the vertical speed of vehicle  131  has increased. Therefore, landing scenario  1000 A suggests that the vehicle  131  is rapidly approaching the abort point  706  with considerable deviation of the vehicle  131  from landing zone center  404  remaining. Once the vehicle reaches the abort point, there will no longer be an opportunity to adjust the orientation of the vehicle. Landing scenario  1000 A may suggest to a pilot or remote pilot that the vertical speed of the vehicle  131  needs to be quickly decreased in order to continue with adjusting the orientation of the vehicle before a warning is issued. 
     Landing scenario  10006  depicts the use of the landing aids according to the present disclosure. Landing scenario  1000 B may depict a scenario where there is significant deviation of vehicle  131  in proximity to the landing zone center  404  of the intended landing zone  402 . In landing scenario  1000 B vehicle  131  is almost completely outside of landing aid symbol  406 . Therefore, landing aid symbol  406  displays landing deviation  414 . Furthermore, landing scenario  1000 B demonstrates that landing aid symbol  406 , displays a color (e.g., red) corresponding with landing deviation  414  around nearly half the circumference of landing aid symbol  406 . 
     Landing scenario  1000 B also depicts that vehicle symbol  702  has reached the abort point  706  on the time/altitude relative to touchdown scale  704 . Vehicle symbol  702  displays a color (e.g., red) to indicate that the vertical speed of vehicle  131  is beyond tolerance. Further,  1000 B represents a scenario where a “GO AROUND” warning is displayed when there is significant deviation of vehicle  131  in proximity to the landing zone center  404  and the vehicle  131  has reached a point where adjustments can no longer be made to the orientation of the vehicle in time for a safe landing. 
       FIG.  11    depicts an example system that may execute techniques presented herein.  FIG.  11    is a simplified functional block diagram of a computer that may be configured to execute techniques described herein, according to exemplary embodiments of the present disclosure. Specifically, the computer (or “platform” as it may not be a single physical computer infrastructure) may include a data communication interface  1160  for packet data communication. The platform may also include a central processing unit (“CPU”)  1120 , in the form of one or more processors, for executing program instructions. The platform may include an internal communication bus  1110 , and the platform may also include a program storage and/or a data storage for various data files to be processed and/or communicated by the platform such as ROM  1130  and RAM  1140 , although the system  1100  may receive programming and data via network communications. The system  1100  also may include input and output ports  1150  to connect with input and output devices such as keyboards, mice, touchscreens, monitors, displays, etc. Of course, the various system functions may be implemented in a distributed fashion on a number of similar platforms, to distribute the processing load. Alternatively, the systems may be implemented by appropriate programming of one computer hardware platform. 
     The general discussion of this disclosure provides a brief, general description of a suitable computing environment in which the present disclosure may be implemented. In one embodiment, any of the disclosed systems, methods, and/or graphical user interfaces may be executed by or implemented by a computing system consistent with or similar to that depicted and/or explained in this disclosure. Although not required, aspects of the present disclosure are described in the context of computer-executable instructions, such as routines executed by a data processing device, e.g., a server computer, wireless device, and/or personal computer. Those skilled in the relevant art will appreciate that aspects of the present disclosure can be practiced with other communications, data processing, or computer system configurations, including: Internet appliances, hand-held devices (including personal digital assistants (“PDAs”)), wearable computers, all manner of cellular or mobile phones (including Voice over IP (“VoIP”) phones), dumb terminals, media players, gaming devices, virtual reality devices, multi-processor systems, microprocessor-based or programmable consumer electronics, set-top boxes, network PCs, mini-computers, mainframe computers, and the like. Indeed, the terms “computer,” “server,” and the like, are generally used interchangeably herein, and refer to any of the above devices and systems, as well as any data processor. 
     Aspects of the present disclosure may be embodied in a special purpose computer and/or data processor that is specifically programmed, configured, and/or constructed to perform one or more of the computer-executable instructions explained in detail herein. While aspects of the present disclosure, such as certain functions, are described as being performed exclusively on a single device, the present disclosure may also be practiced in distributed environments where functions or modules are shared among disparate processing devices, which are linked through a communications network, such as a Local Area Network (“LAN”), Wide Area Network (“WAN”), and/or the Internet. Similarly, techniques presented herein as involving multiple devices may be implemented in a single device. In a distributed computing environment, program modules may be located in both local and/or remote memory storage devices. 
     Aspects of the present disclosure may be stored and/or distributed on non-transitory computer-readable media, including magnetically or optically readable computer discs, hard-wired or preprogrammed chips (e.g., EEPROM semiconductor chips), nanotechnology memory, biological memory, or other data storage media. Alternatively, computer implemented instructions, data structures, screen displays, and other data under aspects of the present disclosure may be distributed over the Internet and/or over other networks (including wireless networks), on a propagated signal on a propagation medium (e.g., an electromagnetic wave(s), a sound wave, etc.) over a period of time, and/or they may be provided on any analog or digital network (packet switched, circuit switched, or other scheme). 
     Program aspects of the technology may be thought of as “products” or “articles of manufacture” typically in the form of executable code and/or associated data that is carried on or embodied in a type of machine-readable medium. “Storage” type media include any or all of the tangible memory of the computers, processors or the like, or associated modules thereof, such as various semiconductor memories, tape drives, disk drives and the like, which may provide non-transitory storage at any time for the software programming. All or portions of the software may at times be communicated through the Internet or various other telecommunication networks. Such communications, for example, may enable loading of the software from one computer or processor into another, for example, from a management server or host computer of the mobile communication network into the computer platform of a server and/or from a server to the mobile device. Thus, another type of media that may bear the software elements includes optical, electrical and electromagnetic waves, such as used across physical interfaces between local devices, through wired and optical landline networks and over various air-links. The physical elements that carry such waves, such as wired or wireless links, optical links, or the like, also may be considered as media bearing the software. As used herein, unless restricted to non-transitory, tangible “storage” media, terms such as computer or machine “readable medium” refer to any medium that participates in providing instructions to a processor for execution. 
     The terminology used above may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized above; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Both the foregoing general description and the detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. 
     As used herein, the terms “comprises,” “comprising,” “having,” including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. 
     In this disclosure, relative terms, such as, for example, “about,” “substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in a stated value. 
     The term “exemplary” is used in the sense of “example” rather than “ideal.” As used herein, the singular forms “a,” “an,” and “the” include plural reference unless the context dictates otherwise. 
     Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.