FieldOfView

Field of view object belonging to satellite scenario

Since R2021a

Description

The FieldOfView object defines a field of view object belonging to a satellite scenario.

You can use the field of view object to visualize the field of view of the conical sensor. It draws a contour on the Earth that represents the line of intersection of the conical region defining the field of view of the sensor and the Earth. For more information on how to use field of view object in a real scenario, see, Satellite Constellation Access to Ground Station.

Creation

You can create a FieldOfView object using the fieldOfView object function of the ConicalSensor object.

Properties

LineWidth — Visual width of field of view contour

1 (default) | scalar in the range (0 10]

Visual width of the field of view contour in pixels, specified as a scalar in the range (0 10].

The line width cannot be thinner than the width of a pixel. If you set the line width to a value that is less than the width of a pixel on your system, the line displays as one pixel wide.

LineColor — Color of field of view contour

[0 1 0] (default) | RGB triplet | RGB triplet | string scalar of color name | character vector of color name

Color of field of view contour, specified as an RGB triplet, hexadecimal color code, a color name, or a short name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1], for example, [0.4 0.6 0.7].

• A hexadecimal color code is a string scalar or character vector that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Therefore, the color codes "#FF8800", "#ff8800", "#F80", and "#f80" are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
"red"	"r"	[1 0 0]	"#FF0000"
"green"	"g"	[0 1 0]	"#00FF00"
"blue"	"b"	[0 0 1]	"#0000FF"
"cyan"	"c"	[0 1 1]	"#00FFFF"
"magenta"	"m"	[1 0 1]	"#FF00FF"
"yellow"	"y"	[1 1 0]	"#FFFF00"
"black"	"k"	[0 0 0]	"#000000"
"white"	"w"	[1 1 1]	"#FFFFFF"
"none"	Not applicable	Not applicable	Not applicable	No color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB^® uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	"#0072BD"
[0.8500 0.3250 0.0980]	"#D95319"
[0.9290 0.6940 0.1250]	"#EDB120"
[0.4940 0.1840 0.5560]	"#7E2F8E"
[0.4660 0.6740 0.1880]	"#77AC30"
[0.3010 0.7450 0.9330]	"#4DBEEE"
[0.6350 0.0780 0.1840]	"#A2142F"

Example: 'blue'

Example: [0 0 1]

Example: '#0000FF'

VisibilityMode — Visibility mode of field of view contour

'inherit' (default) | 'manual'

Visibility mode of the field of view contour, specified as one of these values:

• 'inherit' — Visibility of the graphic matches that of the parent

• 'manual' — Visibility of the graphic is not inherited and is independent of that of the parent

Object Functions

show	Show object in satellite scenario viewer
hide	Hide satellite scenario entity from viewer

Examples

Calculate Maximum Revisit Time of Satellite

Create a satellite scenario with a start time of 15-June-2021 8:55:00 AM UTC and a stop time of five days later. Set the simulation sample time to 60 seconds.

startTime = datetime(2021,6,21,8,55,0);
stopTime = startTime + days(5);
sampleTime = 60;                                      % seconds
sc = satelliteScenario(startTime,stopTime,sampleTime)

sc = 
  satelliteScenario with properties:

         StartTime: 21-Jun-2021 08:55:00
          StopTime: 26-Jun-2021 08:55:00
        SampleTime: 60
      AutoSimulate: 1
        Satellites: [1×0 matlabshared.satellitescenario.Satellite]
    GroundStations: [1×0 matlabshared.satellitescenario.GroundStation]
         Platforms: [1×0 matlabshared.satellitescenario.Platform]
           Viewers: [0×0 matlabshared.satellitescenario.Viewer]
          AutoShow: 1

Add a satellite to the scenario using Keplerian orbital elements.

semiMajorAxis = 7878137;                                                                    % meters
eccentricity = 0;
inclination = 50;                                                                           % degrees
rightAscensionOfAscendingNode = 0;                                                          % degrees
argumentOfPeriapsis = 0;                                                                    % degrees
trueAnomaly = 50;                                                                           % degrees
sat = satellite(sc,semiMajorAxis,eccentricity,inclination,rightAscensionOfAscendingNode, ...
    argumentOfPeriapsis,trueAnomaly)

sat = 
  Satellite with properties:

                  Name:  Satellite 1
                    ID:  1
        ConicalSensors:  [1x0 matlabshared.satellitescenario.ConicalSensor]
               Gimbals:  [1x0 matlabshared.satellitescenario.Gimbal]
          Transmitters:  [1x0 satcom.satellitescenario.Transmitter]
             Receivers:  [1x0 satcom.satellitescenario.Receiver]
              Accesses:  [1x0 matlabshared.satellitescenario.Access]
               Eclipse:  [1x0 Aero.satellitescenario.Eclipse]
           GroundTrack:  [1x1 matlabshared.satellitescenario.GroundTrack]
                 Orbit:  [1x1 matlabshared.satellitescenario.Orbit]
        CoordinateAxes:  [1x1 matlabshared.satellitescenario.CoordinateAxes]
       OrbitPropagator:  sgp4
           MarkerColor:  [0.059 1 1]
            MarkerSize:  6
             ShowLabel:  true
        LabelFontColor:  [1 1 1]
         LabelFontSize:  15
         Visual3DModel:  
    Visual3DModelScale:  1

Add a ground station, which represents the location to be photographed, to the scenario.

gs = groundStation(sc,Name="Location to Photograph", ...
    Latitude=42.3001,Longitude=-71.3504)                 % degrees

gs = 
  GroundStation with properties:

                 Name:  Location to Photograph
                   ID:  2
             Latitude:  42.3001 degrees
            Longitude:  -71.3504 degrees
             Altitude:  0 meters
    MinElevationAngle:  0 degrees
       ConicalSensors:  [1x0 matlabshared.satellitescenario.ConicalSensor]
              Gimbals:  [1x0 matlabshared.satellitescenario.Gimbal]
         Transmitters:  [1x0 satcom.satellitescenario.Transmitter]
            Receivers:  [1x0 satcom.satellitescenario.Receiver]
             Accesses:  [1x0 matlabshared.satellitescenario.Access]
              Eclipse:  [1x0 Aero.satellitescenario.Eclipse]
       CoordinateAxes:  [1x1 matlabshared.satellitescenario.CoordinateAxes]
          MarkerColor:  [1 0.4118 0.1608]
           MarkerSize:  6
            ShowLabel:  true
       LabelFontColor:  [1 1 1]
        LabelFontSize:  15

Add a gimbal to the satellite. You can steer this gimbal independently of the satellite.

g = gimbal(sat)

g = 
  Gimbal with properties:

                Name:  Gimbal 3
                  ID:  3
    MountingLocation:  [0; 0; 0] meters
      MountingAngles:  [0; 0; 0] degrees
      ConicalSensors:  [1x0 matlabshared.satellitescenario.ConicalSensor]
        Transmitters:  [1x0 satcom.satellitescenario.Transmitter]
           Receivers:  [1x0 satcom.satellitescenario.Receiver]
      CoordinateAxes:  [1x1 matlabshared.satellitescenario.CoordinateAxes]

Track the location to be photographed using the gimbal.

pointAt(g,gs);

Add a conical sensor to the gimbal. This sensor represents the camera. Set the field of view to 60 degrees.

camSensor = conicalSensor(g,MaxViewAngle=60)

camSensor = 
  ConicalSensor with properties:

                Name:  Conical sensor 4
                  ID:  4
    MountingLocation:  [0; 0; 0] meters
      MountingAngles:  [0; 0; 0] degrees
        MaxViewAngle:  60 degrees
            Accesses:  [1x0 matlabshared.satellitescenario.Access]
         FieldOfView:  [0x0 matlabshared.satellitescenario.FieldOfView]
      CoordinateAxes:  [1x1 matlabshared.satellitescenario.CoordinateAxes]

Add access analysis to the conical sensor between the camera and the location to be photographed.

ac = access(camSensor,gs)

ac = 
  Access with properties:

    Sequence:  [4 2]
    LineWidth:  3
    LineColor:  [0.3922 0.8314 0.0745]

Visualize the field of view of the camera by using the Satellite Scenario Viewer.

v = satelliteScenarioViewer(sc);
fieldOfView(camSensor);

Determine the intervals during which the camera can see the geographical site.

t = accessIntervals(ac)

t=35×8 table
          Source                   Target             IntervalNumber         StartTime                EndTime           Duration    StartOrbit    EndOrbit
    __________________    ________________________    ______________    ____________________    ____________________    ________    __________    ________

    "Conical sensor 4"    "Location to Photograph"           1          21-Jun-2021 10:38:00    21-Jun-2021 10:55:00      1020           1            2   
    "Conical sensor 4"    "Location to Photograph"           2          21-Jun-2021 12:36:00    21-Jun-2021 12:58:00      1320           2            3   
    "Conical sensor 4"    "Location to Photograph"           3          21-Jun-2021 14:37:00    21-Jun-2021 15:01:00      1440           3            4   
    "Conical sensor 4"    "Location to Photograph"           4          21-Jun-2021 16:41:00    21-Jun-2021 17:04:00      1380           5            5   
    "Conical sensor 4"    "Location to Photograph"           5          21-Jun-2021 18:44:00    21-Jun-2021 19:07:00      1380           6            6   
    "Conical sensor 4"    "Location to Photograph"           6          21-Jun-2021 20:46:00    21-Jun-2021 21:08:00      1320           7            7   
    "Conical sensor 4"    "Location to Photograph"           7          21-Jun-2021 22:50:00    21-Jun-2021 23:04:00       840           8            8   
    "Conical sensor 4"    "Location to Photograph"           8          22-Jun-2021 09:51:00    22-Jun-2021 10:02:00       660          13           13   
    "Conical sensor 4"    "Location to Photograph"           9          22-Jun-2021 11:46:00    22-Jun-2021 12:07:00      1260          14           15   
    "Conical sensor 4"    "Location to Photograph"          10          22-Jun-2021 13:46:00    22-Jun-2021 14:10:00      1440          15           16   
    "Conical sensor 4"    "Location to Photograph"          11          22-Jun-2021 15:49:00    22-Jun-2021 16:13:00      1440          16           17   
    "Conical sensor 4"    "Location to Photograph"          12          22-Jun-2021 17:53:00    22-Jun-2021 18:16:00      1380          18           18   
    "Conical sensor 4"    "Location to Photograph"          13          22-Jun-2021 19:55:00    22-Jun-2021 20:18:00      1380          19           19   
    "Conical sensor 4"    "Location to Photograph"          14          22-Jun-2021 21:58:00    22-Jun-2021 22:16:00      1080          20           20   
    "Conical sensor 4"    "Location to Photograph"          15          23-Jun-2021 10:56:00    23-Jun-2021 11:16:00      1200          26           27   
    "Conical sensor 4"    "Location to Photograph"          16          23-Jun-2021 12:56:00    23-Jun-2021 13:19:00      1380          27           28   
      ⋮

Calculate the maximum revisit time in hours.

startTimes = t.StartTime;
endTimes = t.EndTime;
revisitTimes = hours(startTimes(2:end) - endTimes(1:end-1));
maxRevisitTime = max(revisitTimes)                             % hours

maxRevisitTime = 
  12.666666666666666

Visualize the revisit times that the camera photographs of the location.

play(sc);

Version History

Introduced in R2021a