FOSS4G2023Workshop_How-to-implement-OGC-API

FOSS4G 2023 Seoul Half-day workshop > OGC API – MF, an introduction with MF-API Server based on pygeoapi and MobilityDB > How to implement OGC API – MF with pygeoapi and MobilityDB? Each section describes the commands and sample data used.

Recommended PC specifications

• HDD：At least 20GB free space
• memory >= 6GB
• Install Docker on local PC (https://www.docker.com/get-started)
• (optional) Database Viewer DBeaver (https://dbeaver.io/)

---

<5 mins> A brief explanation of pygeoapi (overall architecture, etc.) and install MF-API Server (using Docker)

Execute the following three commands in order at the command prompt

Step1

docker pull ghcr.io/taehoonk/mf-api-server:1.1

Step2

docker run -p 8085:8085 -p 25432:5432 -d --name mf-api-server ghcr.io/taehoonk/mf-api-server:1.1

Step3

docker exec mf-api-server ./run.sh

---

<10 mins> A brief explanation of MobilityDB and the functions (and structure) used to handle TemporalGeometry and properties.

Note

• There are no commands or data to use.

---

<20 mins> Describe how you extended pygeoapi to support OGC API – MF (libraries to use OpenAPI and MobilityDB (pyMEOS, python-mobilitydb, etc.) and extension structure, etc.)

Note

• There are no commands or data to use.

---

<30 mins> Verify that each API works properly using Swagger

MovingFeatureCollection

No.1

[POST] MovingFeatureCollection

Request body(application/json)

{
  "title": "moving_feature_collection_sample1",
  "updateFrequency": 1000,
  "description": "FOSS4G2023 Seoul Workshop"
}

---

No.2

[GET] MovingFeatureCollection

collectionID

Note

• The last part of location link when POST response

---

No.3

[PUT] MovingFeatureCollection

collectionID : The last part of location link when POST response

Request body(application/json)

{
  "title": "moving_feature_collection_sample2",
  "updateFrequency": 1000,
  "description": "FOSS4G2023 Seoul Workshop PUT test"
}

---

No.4

[DELETE] MovingFeatureCollection

Note

Skip the DELETE request for the next demonstration

---

MovingFeature

No.5

[POST] MovingFeatures

collectionID : ID of the response at the time of MovingFeatureCollection

Request body(application/json) :

{
  "type": "Feature",
  "crs": {
    "type": "Name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "trs": {
    "type": "Link",
    "properties": {
      "type": "OGCDEF",
      "href": "http://www.opengis.net/def/uom/ISO-8601/0/Gregorian"
    }
  },
  "temporalGeometry": {
    "type": "MovingPoint",
    "datetimes": [
      "2011-08-14T22:10:00Z",
      "2011-08-14T22:20:00Z",
      "2011-08-14T22:30:00Z",
      "2011-08-14T22:40:00Z",
      "2011-08-14T23:00:00Z"
    ],
    "coordinates": [
      [
        139.757083,
        35.627701,
        0.5
      ],
      [
        139.757399,
        35.627701,
        2
      ],
      [
        139.757555,
        35.627688,
        4
      ],
      [
        139.757651,
        35.627596,
        4
      ],
      [
        139.757716,
        35.627483,
        4
      ]
    ],
    "interpolation": "Linear",
    "base": {
      "type": "glTF",
      "href": "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/car3dmodel.gltf"
    },
    "orientations": [
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          0
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          355,
          0
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          330
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          300
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          270
        ]
      }
    ]
  },
  "temporalProperties": [
    {
      "datetimes": [
        "2011-08-14T22:10:00Z",
        "2011-08-14T22:30:00Z",
        "2011-08-14T23:00:00Z"
      ],
      "length": {
        "type": "Measure",
        "form": "http://www.qudt.org/qudt/owl/1.0.0/quantity/Length",
        "values": [
          1,
          2.4,
          1
        ],
        "interpolation": "Linear"
      },
      "discharge": {
        "type": "Measure",
        "form": "MQS",
        "values": [
          3,
          4,
          5
        ],
        "interpolation": "Step"
      }
    },
    {
      "datetimes": [
        1465621816590,
        1465711526300
      ],
      "camera": {
        "type": "Image",
        "values": [
          "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/image1",
          "iVBORw0KGgoAAAANSUhEU......"
        ],
        "interpolation": "Discrete"
      },
      "labels": {
        "type": "Text",
        "values": [
          "car",
          "human"
        ],
        "interpolation": "Discrete"
      }
    }
  ],
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [
        139.757083,
        35.627701,
        0.5
      ],
      [
        139.757399,
        35.627701,
        2
      ],
      [
        139.757555,
        35.627688,
        4
      ],
      [
        139.757651,
        35.627596,
        4
      ],
      [
        139.757716,
        35.627483,
        4
      ]
    ]
  },
  "properties": {
    "name": "car1",
    "state": "test1",
    "video": "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/video.mpeg"
  },
  "bbox": [
    139.757083,
    35.627483,
    0,
    139.757716,
    35.627701,
    4.5
  ],
  "time": [
    "2011-08-14T22:00:00Z",
    "2011-08-14T23:00:00Z"
  ]
}

---

No.5-2

[POST] MovingFeatures

collectionID : ID of the response at the time of MovingFeatureCollection

Request body(application/json) :

{
  "type": "Feature",
  "crs": {
    "type": "Name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "trs": {
    "type": "Link",
    "properties": {
      "type": "OGCDEF",
      "href": "http://www.opengis.net/def/uom/ISO-8601/0/Gregorian"
    }
  },
  "temporalGeometry": {
    "type": "MovingPoint",
    "datetimes": [
      "2012-07-14T22:00:00Z",
      "2012-07-14T22:10:00Z",
      "2012-07-14T22:20:00Z",
      "2012-07-14T22:30:00Z",
      "2012-07-14T22:40:00Z"
    ],
    "coordinates": [
      [
        138.757083,
        34.627701,
        0.5
      ],
      [
        138.757399,
        34.627701,
        2
      ],
      [
        138.757555,
        34.627688,
        4
      ],
      [
        138.757651,
        34.627596,
        4
      ],
      [
        138.757716,
        34.627483,
        4
      ]
    ],
    "interpolation": "Linear",
    "base": {
      "type": "glTF",
      "href": "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/car3dmodel.gltf"
    },
    "orientations": [
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          0
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          355,
          0
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          330
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          300
        ]
      },
      {
        "scales": [
          1,
          1,
          1
        ],
        "angles": [
          0,
          0,
          270
        ]
      }
    ]
  },
  "temporalProperties": [
    {
      "datetimes": [
        "2011-07-14T22:00:00Z",
        "2011-07-14T22:30:00Z",
        "2011-07-14T23:00:00Z"
      ],
      "length": {
        "type": "Measure",
        "form": "http://www.qudt.org/qudt/owl/1.0.0/quantity/Length",
        "values": [
          1,
          2.4,
          1
        ],
        "interpolation": "Linear"
      },
      "discharge": {
        "type": "Measure",
        "form": "MQS",
        "values": [
          3,
          4,
          5
        ],
        "interpolation": "Step"
      }
    },
    {
      "datetimes": [
        1465621816590,
        1465711526300
      ],
      "camera": {
        "type": "Image",
        "values": [
          "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/image1",
          "iVBORw0KGgoAAAANSUhEU......"
        ],
        "interpolation": "Discrete"
      },
      "labels": {
        "type": "Text",
        "values": [
          "car",
          "human"
        ],
        "interpolation": "Discrete"
      }
    }
  ],
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [
        138.757083,
        34.627701,
        0.5
      ],
      [
        138.757399,
        34.627701,
        2
      ],
      [
        138.757555,
        34.627688,
        4
      ],
      [
        138.757651,
        34.627596,
        4
      ],
      [
        138.757716,
        34.627483,
        4
      ]
    ]
  },
  "properties": {
    "name": "car1",
    "state": "test1",
    "video": "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/video.mpeg"
  },
  "bbox": [
    138.757083,
    34.627483,
    0,
    138.757716,
    34.627701,
    4.5
  ],
  "time": [
    "2012-07-14T22:00:00Z",
    "2012-07-14T23:00:00Z"
  ]
}

---

No.6

[GET] MovingFeatures (/collections/{collectionId}/items)

collectionID : ID of the response at the time of MovingFeatureCollection

bbox : Empty

datetime : 2011-08-14T22:20:00Z

limit : 10

subTrajectory : --

---

No.6-2

[GET] MovingFeatures (/collections/{collectionId}/items)

collectionID : ID of the response at the time of MovingFeatureCollection

bbox : 138.757083 34.627483 138.757716 34.627701

datetime : 2010-01-01T00:00:00Z/..

limit : 10

subTrajectory : --

---

No.6-3

[GET] MovingFeatures (/collections/{collectionId}/items)

collectionID : ID of the response at the time of MovingFeatureCollection

bbox : Empty

datetime : 2011-08-14T22:15:00Z/2011-08-14T22:55:00Z

limit : 10

subTrajectory : true

---

No.7

[GET] MovingFeatures (/collections/{collectionId}/items/{mFeatureId})

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeature

Note

The last part of location link when MovingFeatures POST response

---

No.8

[DELETE] MovingFeatures (/collections/{collectionId}/items/{mFeatureId})

Note

Skip the DELETE request for the next demonstration

---

TemporalGeometryCollection

No.9

[POST] TemporalGeometry(/collections/{collectionId}/items/{mFeatureId}/tgsequence)

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

Request body(application/json) : Default Value

---

No.10

[GET] TemporalGeometry(/collections/{collectionId}/items/{mFeatureId}/tgsequence)

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

leaf : 2011-08-14T22:30:00Z

bbox : Empty

datetime : 2010-01-01T00:00:00Z/..

limit : 10

---

No.10-2

[GET] TemporalGeometry(/collections/{collectionId}/items/{mFeatureId}/tgsequence)

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

leaf : Empty

bbox : Empty

datetime : 2011-08-14T22:15:00Z/2011-08-14T22:55:00Z

limit : 10

subTrajectory : true

---

No.11

[DELETE] TemporalGeometry(/collections/{collectionId}/items/{mFeatureId}/tgsequence/{tGeometryId})

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

tGeometryId : ID of the response at the time of TemporalGeometry

Note

• The last part of location link when POST response

---

TemporalProperties

No.12

[POST] TemporalProperties(/collections/{collectionId}/items/{mFeatureId}/tproperties)

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

Request body(application/json) :

{
  "temporalProperties": [
    {
      "datetimes": [
        "2015-07-14T22:01:01.450Z",
        "2015-07-14T23:01:01.450Z",
        "2015-07-15T00:01:01.450Z"
      ],
      "length": {
        "type": "Measure",
        "form": "http://www.qudt.org/qudt/owl/1.0.0/quantity/Length",
        "values": [
          1,
          2.4,
          1
        ],
        "interpolation": "Linear"
      },
      "discharge": {
        "type": "Measure",
        "form": "MQS",
        "values": [
          3,
          4,
          5
        ],
        "interpolation": "Step"
      }
    },
    {
      "datetimes": [
        1466380800000,
        1466383800000
      ],
      "camera": {
        "type": "Image",
        "values": [
          "http://www.opengis.net/spec/movingfeatures/json/1.0/prism/example/image1",
          "iVBORw0KGgoAAAANSUhEU......"
        ],
        "interpolation": "Discrete"
      },
      "labels": {
        "type": "Text",
        "values": [
          "car",
          "human"
        ],
        "interpolation": "Discrete"
      }
    }
  ]
}

---

No.13

[GET] TemporalProperties(/collections/{collectionId}/items/{mFeatureId}/tproperties/)

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

leaf : Empty

datetime : 2011-08-14T22:15:00Z/2011-08-14T22:55:00Z

limit : 10

subTemporalValue : true

---

No.14

[GET] TemporalProperty(/collections/{collectionId}/items/{mFeatureId}/tproperties/{tPropertyName})

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

tPropertyName : length

leaf : Empty

datetime : 2010-01-01T00:00:00Z/..

subTemporalValue : true

---

No.15

[POST] TemporalProperty(/collections/{collectionId}/items/{mFeatureId}/tproperties/{tPropertyName})

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

tPropertyName : length

Request body(application/json) :

{
  "datetimes": [
    "2011-12-15T08:00:00Z",
    "2011-12-15T08:10:00Z",
    "2011-12-15T08:20:00Z"
  ],
  "values": [
    0,
    20,
    50
  ],
  "interpolation": "Linear"
}

---

No.16

[DELETE] TemporalProperty(/collections/{collectionId}/items/{mFeatureId}/tproperties/{tPropertyName})

collectionId : ID of the response at the time of MovingFeatureCollection

mFeatureId : ID of the response at the time of MovingFeatures

tPropertyName : length

---

References

MF-API Server based on pygeoapi https://github.com/aistairc/mf-api

OGC API – MovingFeatures official GitHub repository https://github.com/opengeospatial/ogcapi-movingfeatures

MobilityDB (and its Python driver, PyMEOS, and MEOS) https://github.com/MobilityDB

STINUUM（The installation of each program will use a Docker file.） https://github.com/aistairc/mf-cesium

OGC API – MF helpful information https://ogcapi.ogc.org/movingfeatures/