Systems and methods for using visual landmarks in initial navigation

1 . A method for providing initial navigation guidance, the method comprising:

determining, by one or more processors, a route from a current location of a portable device to a destination, the route including a sequence of directed sections;

generating, by the one or more processors, navigation instructions to guide a user of the portable device along the route to the destination, including, in response to determining that the portable computing device is at rest at the current location:

identifying candidate navigation landmarks perceptible within a 360-degree range of the current location of the portable device using (i) one or more metrics of observability, prominence, and uniqueness and (ii) a user preference related to a type of landmark,

selecting, from among the candidate navigation landmarks, a navigation landmark, and

generating an initial instruction in the navigation instructions, the initial instruction referencing the selected navigation landmark; and

causing the initial navigation instruction to be provided via a user interface of the portable device.

2 . The method of claim 1 , wherein the one or more metrics include a metric of observability; the method further comprising:

generating the metric of observability for a candidate navigation landmark based on a number of photographs of the candidate navigation landmark captured from a same location.

3 . The method of claim 1 , wherein the one or more metrics include a metric of observability; the method further comprising:

generating the metric of observability for a candidate navigation landmark using one or more of (i) three-dimensional (3D) models constructed using scanning, (ii) 3D reconstruction from user photographs, (ii) panoramic imagery, or (iv) aerial imagery.

4 . The method of claim 1 , wherein the one or more metrics include a metric of prominence; the method further comprising:

generating the metric of prominence for a candidate navigation landmark using a number of indexed photographs of the candidate navigation landmark and/or a number of search hits, reviews, and queries related to the candidate navigation landmark.

5 . The method of claim 1 , wherein the one or more metrics include a metric of uniqueness; the method further comprising:

generating the metric of uniqueness for a candidate navigation landmark using proximity of the candidate navigation landmark to other landmarks of a same type.

6 . The method of claim 1 , wherein the selected navigation landmark is a first navigation landmark, and wherein generating the navigation instructions further includes:

selecting, from among the candidate navigation landmarks, a second navigation landmark disposed in a direction opposite to a direction of the first navigation landmark from the current location of the portable device, and

generating the initial instruction referencing the first navigation landmark and the second navigation landmark.

7 . The method of claim 6 , wherein generating the initial instruction includes using a format “travel <direction> from <the first navigation landmark> to <the second navigation landmark>”.

8 . The method of claim 6 , wherein generating the initial instruction further includes:

selecting, for each of the first navigation landmark and the second navigation landmark, a first icon and a second icon, respectively, each icon indicating a type of the landmark,

annotating the initial instruction with the first icon and the second icon.

9 . The method of claim 1 , wherein identifying the candidate navigation landmarks includes identifying an auditory navigation landmark corresponding to a source of an audio signal above a noise floor.

10 . The method of claim 1 , wherein identifying the candidate navigation landmarks includes identifying a transient navigation landmark corresponding to a temporary geolocated event.

11 . A system comprising:

processing hardware;

a non-transitory memory readable by the processing hardware and storing thereon instructions that, when executed by the processing hardware, cause the system to:

determine a route from a current location of a portable device to a destination, the route including a sequence of directed sections,

generate navigation instructions to guide a user of the portable device along the route to the destination, including, in response to determining that the portable computing device is at rest at the current location:

identify candidate navigation landmarks perceptible within a 360-degree range of the current location of the portable device using (i) one or more metrics of observability, prominence, and uniqueness and (ii) a user preference related to a type of landmark,

select, from among the candidate navigation landmarks, a navigation landmark,

generate an initial instruction in the navigation instructions, the initial instruction referencing the selected navigation landmark; and

cause the initial navigation instruction to be provided via a user interface of the portable device e.

12 . The system of claim 11 , wherein the one or more metrics include a metric of observability; and wherein the instructions further cause the system to:

generate the metric of observability for a candidate navigation landmark based on a number of photographs of the candidate navigation landmark captured from a same location.

13 . The system of claim 11 , wherein the one or more metrics include a metric of observability; and wherein the instructions further cause the system to:

generate the metric of observability for a candidate navigation landmark using one or more of (i) three-dimensional (3D) models constructed using scanning, (ii) 3D reconstruction from user photographs, (ii) panoramic imagery, or (iv) aerial imagery.

14 . The system of claim 11 , wherein the one or more metrics include a metric of prominence; and wherein the instructions further cause the system to:

generate the metric of prominence for a candidate navigation landmark using a number of indexed photographs of the candidate navigation landmark and/or a number of search hits, reviews, and queries related to the candidate navigation landmark.

15 . The system of claim 11 , wherein the one or more metrics include a metric of uniqueness; and wherein the instructions further cause the system to:

generate the metric of uniqueness for a candidate navigation landmark using proximity of the candidate navigation landmark to other landmarks of a same type.

16 . The system of claim 11 , wherein the selected navigation landmark is a first navigation landmark, and wherein to generate the navigation instructions, and wherein the instructions further cause the system to:

select, from among the candidate navigation landmarks, a second navigation landmark disposed in a direction opposite to a direction of the first navigation landmark from the current location of the portable device, and

generate the initial instruction referencing the first navigation landmark and the second navigation landmark.

17 . The system of claim 16 , wherein the instructions cause the system to generate the initial instruction in a format “travel <direction> from <the first navigation landmark> to <the second navigation landmark>”.

18 . The system of claim 16 , wherein to generate the initial instruction, the instructions cause the system to:

select, for each of the first navigation landmark and the second navigation landmark, a first icon and a second icon, respectively, each icon indicating a type of the landmark,

annotate the initial instruction with the first icon and the second icon.

19 . The system of claim 11 , wherein to identify the candidate navigation landmarks, the instructions cause the system to identify an auditory navigation landmark corresponding to a source of an audio signal above a noise floor.

20 . The system of claim 11 , wherein to identify the candidate navigation landmarks, the instructions cause the system to identify a transient navigation landmark corresponding to a temporary geolocated event.