There exists many kinds of metric maps and observations in MRPT, but some operations involving a map and an observation (for example "inserting" an observation in a map to update it) only make sense for a small subset of map-observation combinations.

See:

List of all observations: see derived classes from mrpt::obs::CObservation
List of all metric maps: see derived classes from mrpt::maps::CMetricMap

The following tables summarize the valid combinations, as implemented so far:

See: mrpt::maps::CMetricMaps::insertObservation()

Observations	Maps
mrpt::obs::CObservation2DRangeScan	mrpt::maps::CColouredOctoMap, mrpt::maps::CHeightGridMap2D, mrpt::maps::CHeightGridMap2D_MRF, mrpt::maps::COccupancyGridMap2D, mrpt::maps::COctoMap, mrpt::maps::CPointsMap (any derived map)
mrpt::obs::CObservation3DRangeScan	mrpt::maps::CColouredOctoMap, mrpt::maps::COctoMap, mrpt::maps::CPointsMap (any derived map)
mrpt::obs::CObservation6DFeatures
mrpt::obs::CObservationBeaconRanges	mrpt::maps::CBeaconMap (see RO-SLAM)
mrpt::obs::CObservationBearingRange
mrpt::obs::CObservationGasSensors	mrpt::maps::CGasConcentrationGridMap2D
mrpt::obs::CObservationGPS
mrpt::obs::CObservationImage	mrpt::maps::CLandmarksMap (Extract SIFT feats)
mrpt::obs::CObservationIMU
mrpt::obs::CObservationOdometry
mrpt::obs::CObservationPointCloud	mrpt::maps::CPointsMap (any derived map)
mrpt::obs::CObservationRange	mrpt::maps::CPointsMap (any derived map), mrpt::maps::COccupancyGridMap2D
mrpt::obs::CObservationReflectivity	mrpt::maps::CReflectivityGridMap2D
mrpt::obs::CObservationRFID
mrpt::obs::CObservationRGBD360
mrpt::obs::CObservationRobotPose
mrpt::obs::CObservationStereoImages	mrpt::maps::CLandmarksMap (Extract SIFT feats)
mrpt::obs::CObservationStereoImagesFeatures	mrpt::maps::CLandmarksMap (Append/fuse landmarks)
mrpt::obs::CObservationVelodyneScan	mrpt::maps::CPointsMap (any derived map), mrpt::maps::CHeightGridMap2D, mrpt::maps::CHeightGridMap2D_MRF
mrpt::obs::CObservationWindSensor
mrpt::obs::CObservationWirelessPower	mrpt::maps::CWirelessPowerGridMap2D

See: mrpt::maps::CMetricMaps::computeObservationLikelihood()

Observations	Maps
mrpt::obs::CObservation2DRangeScan	mrpt::maps::CColouredOctoMap, mrpt::maps::CPointsMap (any derived map), mrpt::maps::COccupancyGridMap2D, mrpt::maps::COctoMap, mrpt::maps::CLandmarksMap
mrpt::obs::CObservation3DRangeScan	mrpt::maps::CColouredOctoMap & mrpt::maps::COctoMap (must have pointcloud)
mrpt::obs::CObservation6DFeatures
mrpt::obs::CObservationBeaconRanges	mrpt::maps::CBeaconMap (Used for SLAM), mrpt::maps::CLandmarksMap (Used for localization-only)
mrpt::obs::CObservationBearingRange
mrpt::obs::CObservationGasSensors
mrpt::obs::CObservationGPS	mrpt::maps::CLandmarksMap (NMEA GGA datum)
mrpt::obs::CObservationImage
mrpt::obs::CObservationIMU
mrpt::obs::CObservationOdometry
mrpt::obs::CObservationPointCloud	mrpt::maps::CPointsMap (any derived map), mrpt::maps::CColouredOctoMap & mrpt::maps::COctoMap
mrpt::obs::CObservationRange
mrpt::obs::CObservationReflectivity	mrpt::maps::CReflectivityGridMap2D
mrpt::obs::CObservationRFID
mrpt::obs::CObservationRGBD360
mrpt::obs::CObservationRobotPose	mrpt::maps::CLandmarksMap
mrpt::obs::CObservationStereoImages	mrpt::maps::CLandmarksMap (Convert to SIFT features)
mrpt::obs::CObservationStereoImagesFeatures
mrpt::obs::CObservationVelodyneScan	mrpt::maps::CPointsMap (any derived map), mrpt::maps::CColouredOctoMap & mrpt::maps::COctoMap
mrpt::obs::CObservationWindSensor
mrpt::obs::CObservationWirelessPower