AIS Position Validation

Spire uses Advanced RF signal-based vessel detection and tracking to validate vessels’ positions based on the unique real time coverage offered by Spire’s satellite constellation.

AIS Position Validation independently calculates a vessel’s location at the time of the AIS transmission even if the AIS messages transmitted by the vessel do not include valid GPS data.

This data is accessible via ShipView™ as well as Geospatial Web Services™ (GWS). There are two GWS APIs available which provide:

Summary View – Provides counts of validated and anomaly events within last 7 days of the most recent AIS position validation event for any given vessel. Also provides the last reported AIS position of the vessel during the validation of the event
Detailed View – Provides full information on detected events for any vessel i.e. event type, associated reported and estimated positions and relative distances (in kms) between estimated and reported positions

These GWS deliver the data in two formats that are Open Geospatial Consortium (OGC) compliant:

The Web Feature Services (WFS) allow users to get features (data) in a variety of standard formats, including CSV, GML, GeoJSON, and Shapefile.
The Web Map Services (WMS) allow users to get requested images of Spire AIS data in a variety of formats including PNG, JPEG, KML, etc.

Want to learn more the use cases, advantages and KPIs?

Visit our AIS Position validation product page to learn more about this groundbreaking solution from Spire Maritime.

Learn more about AIS Position Validation

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Summary View

Data set content

Data sets returned by Summary View in response to requests made by end users contain fields in a specific sequential order.

The order in which those fields are returned is documented in the data schema tables listed in this section. Data ingest methods that depend on field order, specifically commas separated values (.csv) format, need to take this into account.

The data content description, including field descriptions and schemas are presented below.

Abstract: Summary View (RFGL-TARGET) provides information about vessels such as latest validated and anomaly AIS Position Validation events, counts and timestamps. This layer also includes the reported AIS information used for validating the event for any given MMSI.
Data Sources: Satellite and Terrestrial and Vessel-AIS (S/T/V-AIS)
Geographic Area of Interest: Global or User-Defined
AOI Vessel Types: Class A and B
Geographic Data: Point (WGS84)
Vessel Identification Data Fields: mmsi, imo, vessel_name, callsign, vessel_type, vessel_type_code, vessel_type_cargo, flag_country, flag_code, vessel_class, vessel_type_main, vessel_type_sub
Vessel Positional Data Fields: ts_pos_utc, dt_pos_utc, position (Point –WGS84), longitude, latitude, sog, cog, rot, heading, nav_status, nav_status_code, source, ts_insert_utc, dt_insert_utc, message_type
Vessel Static/Voyage Information Data Fields: ts_static_utc, dt_static_utc, length, width, destination, eta, draught
RFGL Target Service Data Fields: rgfl_latest_validated_event, rgfl_latest_validated_event_source, rfgl_validated_count, rfgl_latest_validated_dtg, rfgl_latest_is_validated, rgfl_latest_anomaly_event, rgfl_latest_anomaly_event_source, rfgl_anomaly_count, rfgl_latest_anomaly_dtg
Geometry: Point (WGS84)

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Data schema

[0] id [Json] / fid [CSV, GML 2] / gml:id [GML 3 & 3.2 Xml Attribute]
[1] mmsi
[2] imo
[3] vessel_name
[4] callsign
[5] vessel_type
[6] vessel_type_code
[7] vessel_type_cargo
[8] vessel_class
[9] length
[10] width
[11] flag_country
[12] flag_code
[13] destination
[14] eta
[15] draught
[16] position
[17] longitude
[18] latitude
[19] sog
[20] cog
[21] rot
[22] heading
[23] nav_status
[24] nav_status_code
[25] source
[26] ts_pos_utc
[27] ts_static_utc
[28] ts_insert_utc
[29] dt_pos_utc
[30] dt_static_utc
[31] dt_insert_utc
[32] vessel_type_main
[33] vessel_type_sub
[34] message_type
[35] rgfl_latest_validated_event
[36] rgfl_latest_validated_event_source
[37] rfgl_validated_count
[38] rfgl_latest_validated_dtg
[39] rfgl_latest_is_validated
[40] rgfl_latest_anomaly_event
[41] rgfl_latest_anomaly_event_source
[42] rfgl_anomaly_count
[43] rfgl_latest_anomaly_dtg

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WMS customization

Layer style

Spire Maritime provides a variety of styles that can be used to customize the look and feel of rendered maps.

The [styles] query string parameter of a WMS request provides the interface to enter a style to define the symbology to apply to the map output, “styles=[STYLE]”.

Vessel (Default): Vessel symbol, single color, rotation by [cog]
VesselByType: Vessel symbol, color by [vessel_type], rotation by [cog]
VesselBySpeed: Vessel symbol, single color, rotation by [cog], leader line symbol by [sog]
VesselBySpeedGrouped: Vessel symbol, color by [sog], rotation by [cog]
VesselByTypeSpeed: Vessel symbol, color by [vessel_type_code], rotation by [cog], leader line symbol by [sog]
VesselSpeedVector: Leader line symbol by [sog], rotation by [cog]
VesselBySource: Vessel symbol, color by [source], rotation by [cog]
VesselByClass: Vessel symbol, color by [class], rotation by [cog]
VesselLabel: Vessel symbol, single color, rotation by [cog], label by [vessel_name]
VesselLabelOverlay: Label by [vessel_name]
VesselLabelDateTime: Circle point symbol, single color, label by [ts_pos_utc]
VesselLabelDateTimeOverlay: Label by [ts_pos_utc]
RFGLTarget: Vessel symbol, color by [rfgl_latest_is_validated], rotation by[cog]

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Detailed View

Data set content

Data sets returned by Detailed View in response to requests made by end users contain fields in a specific sequential order.

The data content description, including field descriptions and schemas are presented below.

Abstract: Detailed View (RFGL-EVENT) provides full information about AIS Position Validation events such as reported and estimated positions including relative distances in kilometers for validated and anomaly event types within any given 24-hour period going back up to October 18 2022, defaulted to last 24 hours.
Data Sources: Satellite and Terrestrial and Vessel-AIS (S/T/V-AIS)
Geographic Area of Interest: Global or User-Defined
AOI Vessel Types: Class A and B
Geographic Data: Point (WGS84)
Vessel Identification Data Fields: mmsi, imo, vessel_name, callsign, vessel_type, vessel_type_code, vessel_type_cargo, flag_country, flag_code, vessel_class, vessel_type_main, vessel_type_sub
Vessel Positional Data Fields: ts_pos_utc, dt_pos_utc, position (Point –WGS84), longitude, latitude, sog, cog, rot, heading, nav_status, nav_status_code, source, ts_insert_utc, dt_insert_utc, message_type
Vessel Static/Voyage Information Data Fields: ts_static_utc, dt_static_utc, length, width, destination, eta, draught
RFGL Event Service Data Fields: rfgl_dtg, rfgl_reported_position, rfgl_reported_longitude, rfgl_reported_latitude, rfgl_estimated_position, rfgl_estimated_longitude, rfgl_estimated_latitude, rfgl_estimated_reported_delta_km, rfgl_estimated_reported_segment, rfgl_event_type, rfgl_event_type_source
Geometry: Point (WGS84)

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Data schema

[0] id [Json] / fid [CSV, GML 2] / gml:id [GML 3 & 3.2 Xml Attribute]
[1] mmsi
[2] imo
[3] vessel_name
[4] callsign
[5] vessel_type
[6] vessel_type_code
[7] vessel_type_cargo
[8] vessel_class
[9] length
[10] width
[11] flag_country
[12] flag_code
[13] destination
[14] eta
[15] draught
[16] position
[17] longitude
[18] latitude
[19] sog
[20] cog
[21] rot
[22] heading
[23] nav_status
[24] nav_status_code
[25] source
[26] ts_pos_utc
[27] ts_static_utc
[28] dt_pos_utc
[29] dt_static_utc
[30] vessel_type_main
[31] vessel_type_sub
[32] message_type
[33] rfgl_dtg
[34] rfgl_reported_position
[35] rfgl_reported_longitude
[36] rfgl_reported_latitude
[37] rfgl_estimated_position
[38] rfgl_estimated_longitude
[39] rfgl_estimated_latitude
[40] rfgl_estimated_reported_delta_km
[41] rfgl_estimated_reported_segment
[42] rfgl_event_type
[43] rfgl_event_type_source

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WMS customization

Layer style

Spire Maritime provides a variety of styles that can be used to customize the look and feel of rendered maps.

The [styles] query string parameter of a WMS request provides the interface to enter a style to define the symbology to apply to the map output, “styles=[STYLE]”.

Vessel (Default): Vessel symbol, single color, rotation by [cog]
VesselByType: Vessel symbol, color by [vessel_type], rotation by [cog]
VesselBySpeed: Vessel symbol, single color, rotation by [cog], leader line symbol by [sog]
VesselBySpeedGrouped: Vessel symbol, color by [sog], rotation by [cog]
VesselByTypeSpeed: Vessel symbol, color by [vessel_type_code], rotation by [cog], leader line symbol by [sog]
VesselSpeedVector: Leader line symbol by [sog], rotation by [cog]
VesselBySource: Vessel symbol, color by [source], rotation by [cog]
VesselByClass: Vessel symbol, color by [class], rotation by [cog]
VesselLabel: Vessel symbol, single color, rotation by [cog], label by [vessel_name]
VesselLabelOverlay: Label by [vessel_name]
VesselLabelDateTime: Circle point symbol, single color, label by [ts_pos_utc]
VesselLabelDateTimeOverlay: Label by [ts_pos_utc]
RFGLEvent: Square point symbol [rfgl_estimated_position], circle point symbol [rfgl_reported_position], and dashed line symbol [rfgl_estimated_reported_segment]

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Data definition guide

MMSI Number: Maritime Mobile Service Identity (MMSI)
IMO Number: International Maritime Organization (IMO)
VESSEL_NAME Text: Vessel Name
CALLSIGN Text: Vessel Call Sign
VESSEL_TYPE Text: Vessel Type
VESSEL_TYPE_CODE Number: Vessel Type Code
VESSEL_TYPE_CARGO Text: Vessel Type Cargo
VESSEL_TYPE_MAIN Text: Vessel Type Main
VESSEL_TYPE_SUB Text: Vessel Type Sub-Category
FLAG_COUNTRY Text: Country of Registration
FLAG_CODE Number: Country of Registration Code
VESSEL_CLASS Text: Class of Vessel (A/B)
TS_POS_UTC Timestamp: Date and Time of Last Position AIS Message in UTC [YYYYMMDDHHmmSS]
DT_POS_UTC Timestamp: Date and Time of Last Position AIS Message in UTC [YYYY-MM-DD HH24:MI:SS]
POSITION Geometry: WGS84 Point, Geographic Location
LONGITUDE Number, Decimal Degrees: WGS 84 Longitude Coordinate
LATITUDE Number, Decimal Degrees: WGS 84 Latitude Coordinate
SOG Number, Knots: Speed over Ground
COG Number, Degrees: Course over Ground
ROT Number, Degrees / Min: Rate of Turn
HEADING Number, Degrees: Heading
NAV_STATUS Text: Navigational Status
NAV_STATUS_CODE Number: Navigational Status Code
SOURCE Text: Source of the last AIS position report during the validation of the event (Satellite AIS [S-AIS], Terrestrial AIS [T-AIS], or Vessel AIS [V-AIS])
TS_STATIC_UTC Timestamp: Date and Time of Last Static AIS Message in UTC [YYYYMMDDHHmmSS]
DT_STATIC_UTC Timestamp: Date and Time of Last Static AIS Message in UTC [YYYY-MM-DD HH24:MI:SS]
LENGTH Number, Metres: Length of Bow to Main Tower and Main Tower to Stern
WIDTH Number, Metres: Length of Port to Main Tower and Main Tower to Starboard
DESTINATION Text: Port of Destination
ETA Timestamp: Month, Day, Hour, and Minute of Estimated Time of Arrival in UTC [MMDDHHmm]
DRAUGHT Number, Metres: Vessel Draught
TS_INSERT_UTC Timestamp: Date and Time of Last Insert in UTC [YYYYMMDDHHmmSS]
DT_INSERT_UTC Timestamp: Date and Time of Last Insert in UTC [YYYY-MM-DD HH24:MI:SS]
RGFL_LATEST_VALIDATED_EVENT Text: RFGL Event Type
RGFL_LATEST_VALIDATED_EVENT_SOURCE Text: RFGL Event Type Source
RFGL_VALIDATED_COUNT Number: RFGL Validated Positions Count
RFGL_LATEST_VALIDATED_DTG Timestamp: RFGL Latest Validated Timestamp in UTC
RFGL_LATEST_IS_VALIDATED Boolean: RFGL Latest Is Validated
RGFL_LATEST_ANOMALY_EVENT Text: RFGL Latest Anomaly Event Type
RGFL_LATEST_ANOMALY_EVENT_SOURCE Text: FGL Latest Anomaly Event Type Source
RFGL_ANOMALY_COUNT Number: RFGL Anomaly Positions Count
RFGL_LATEST_ANOMALY_DTG Timestamp: RFGL Latest Anomaly Timestamp in UTC
RFGL_DTG Timestamp: RFGL Timestamp in UTC/dd>
RFGL_REPORTED_POSITION Geometry: WGS84 Point, Reported Vessel Position
RFGL_REPORTED_LONGITUDE Number, Decimal Degrees: WGS 84 Longitude Coordinate
RFGL_REPORTED_LATITUDE Number, Decimal Degrees: WGS 84 Longitude Coordinate
RFGL_ESTIMATED_POSITION Geometry: WGS84 Point, Reported Vessel Position
RFGL_ESTIMATED_LONGITUDE Number, Decimal Degrees: WGS 84 Longitude Coordinate
RFGL_ESTIMATED_LATITUDE Number, Decimal Degrees: WGS 84 Longitude Coordinate
RFGL_ESTIMATED_REPORTED_DELTA_KM Number: Distance between Reported and Estimated Positions
RFGL_ESTIMATED_REPORTED_SEGMENT Number: Distance between Reported and Estimated Positions
RFGL_EVENT_TYPE Text: RFGL Event Type
RFGL_EVENT_TYPE_SOURCE Text: RFGL Event Type Source

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OGC Support

GWS supports all OGC WMS operations from implementation WMS 1.3.0 and all OGC WFS operations from implementations WFS 1.1.0, excluding Transaction.

Service Type	Service Modes	Versions	Common Parameters	Output Formats	Output File Sizes	Response Times
WMS	`GetMap`, `GetCapabilities`, `GetFeatureInfo`, and `GetLegendGraphic`	1.3.0	`SERVICE`, `VERSION`, `REQUEST`, `LAYERS`, `STYLES`, `BBOX`, `WIDTH`, `HEIGHT`, `SRS`, `FORMAT`, and `FILTER`	PNG, JPEG, GIF, and KML/KMZ	Dynamic <1MB	< 3s
WFS	`GetCapabilities`, `GetFeature`, and `DescribeFeatureType`	1.1.0	`SERVICE`, `VERSION`, `REQUEST`, `TYPENAME`, `MAXFEATURES`, `OUTPUTFORMAT`, and `FILTER`	CSV, GML (2, 3.1, 3.2), GeoJSON, and Shapefile	Approx. 1 KB / Record	< 1.5s / 50 Records

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Accessing the web service

Authentication

GWS uses HTTPS and user authentication via user token or user name and password to access information and is available at https://services.exactearth.com/gws.

Service type	URL
WMS	`https://services.exactearth.com/gws/wms?service=wms&version=1.3.0&request=GetCapabilities`
WFS	`https://services.exactearth.com/gws/wfs?service=wfs&version=1.1.0&request=GetCapabilities`

GWS allows users to authenticate access to the services using either a token or basic authentication. Spire provides both a unique token and user name and password for each user. The [authKey] query string parameter of a WMS/WFS request provides the interface to enter a token to access the services using the following notation, “authKey=[TOKEN]”.

For basic authentication, users are required to enter user name and password credentials to access the services, for example, a web browser, OGC-compliant client, or application-level requestor.

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Sorting & filtering

GWS supports optional parameters and capabilities to enhance the usability of the service.

Maximum Features (maxFeatures)

Provides an ability to limit the number of features by request to the WFS services.

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&maxFeatures=10&typenames=exactAIS:RFGL-TARGET

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&maxFeatures=10&typenames=exactAIS:RFGL-EVENT

Sorting (sortBy)

Provides an ability to sort the values in a column in ascending or descending order by request to the WFS services. Sorting by ascending order is the default setting, using “+D” will change the response to sorting by descending order.

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&sortBy=ts_pos_utc+D&typenames=exactAIS:RFGL-TARGET

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&sortBy=ts_pos_utc+D&maxFeatures=10&typenames=exactAIS:RFGL-EVENT

Fields / Columns (propertyName)

Provides an ability to specify the output fields / columns per request. The [propertyName] query string parameter of a WFS request provides the interface to limit the fields / columns returned in the GetFeature request, for example,

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&typenames=exactAIS:RFGL-TARGET&propertyName=mmsi,rfgl_latest_is_validated,rfgl_anomaly_count,rfgl_latest_anomaly_event

https://services.exactearth.com/gws/ows?service=WFS&version=1.1.0&request=GetFeature&outputformat=json&sortBy=ts_pos_utc+D&maxFeatures=10&typenames=exactAIS:RFGL-EVENT&propertyName=mmsi,rfgl_dtg,rfgl_estimated_longitude,rfgl_estimated_latitude,rfgl_estimated_reported_delta_km

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