Earth Science Measurements
Authors:
MArk Anthony Higgins - Sky Recursive Ai
MArk Anthony Higgins - Sky Recursive Ai
© Mark Anthony Higgins 11 October 2025
Revised Date: July 6th 2026
Revised Date: July 6th 2026
# Earth Science Measurements Ontology — Flow Algebra
URL: https://kirethresearch.org/booksai-core/ontologies/mathematical-ontologies/measurement-units-ontologies/earth-science-measurements.html
FLOW EarthScienceMeasurementsOntology {
DOMAIN:
Mathematical Ontologies
-> Measurement & Units Ontologies
-> Earth Science Measurements Ontology
PURPOSE:
Represent the semantic and mathematical structure of Earth science measurements across the atmosphere, hydrosphere, geosphere, cryosphere, biosphere and coupled Earth system, including spatial position, elevation, depth, temperature, pressure, precipitation, wind, water level, discharge, soil and rock properties, seismic quantities, gravity, magnetic field, radiation, remote sensing, temporal and spatial sampling, coordinate reference systems, calibration, uncertainty, provenance, and transformations required for consistent AI interpretation and reasoning.
SCOPE {
atmospheric_measurements
meteorological_measurements
hydrological_measurements
oceanographic_measurements
geological_measurements
geophysical_measurements
seismological_measurements
geomagnetic_measurements
gravitational_measurements
soil_measurements
cryospheric_measurements
remote_sensing_measurements
spatial_measurements
temporal_measurements
environmental_observations
calibration
uncertainty_and_traceability
}
ENTITY EarthScienceMeasurement {
TYPE: MeasurementResult
COMPONENTS:
measurand
numerical_value
unit
Earth_system_domain
spatial_location
vertical_reference
timestamp
sampling_interval
measurement_method
instrument
uncertainty
provenance
}
ENTITY SpatialPosition {
TYPE: GeospatialQuantity
COMPONENTS:
horizontal_coordinates
coordinate_reference_system
vertical_coordinate_when_relevant
RULE:
coordinates_without_CRS_are_semantically_incomplete
}
ENTITY Elevation {
TYPE: LengthQuantity
SYMBOL: h
SI_UNIT: metre
SI_SYMBOL: m
REQUIRE:
vertical_datum_or_reference_surface
}
ENTITY Depth {
TYPE: LengthQuantity
SYMBOL: d
SI_UNIT: metre
SI_SYMBOL: m
RULE:
depth_direction_and_reference_surface MUST be defined
}
UNIT_SYSTEM {
canonical_system:
SI_where_applicable
common_units:
metre
kilometre
millimetre
second
hour
day
kelvin
degree_Celsius
pascal
hectopascal
metre_per_second
millimetre_per_hour
cubic_metre_per_second
kilogram_per_cubic_metre
percent
tesla
nanotesla
metre_per_second_squared
RULE:
quantity_unit_reference_frame_and_sampling_basis MUST be preserved
}
COORDINATE_REFERENCE_MODEL {
horizontal:
latitude_longitude
projected_coordinates
local_coordinates
REQUIRE:
CRS_identifier
axis_order
units
RULE:
coordinate_transformation MUST preserve_source_and_target_CRS
}
VERTICAL_REFERENCE_MODEL {
possible_references:
ellipsoidal_height
orthometric_height
mean_sea_level
chart_datum
ground_surface
instrument_datum
pressure_level
RULE:
elevation_depth_and_water_level MUST preserve_vertical_reference
}
TIME_MODEL {
components:
timestamp
time_zone_or_UTC
observation_duration
averaging_period
sampling_interval
RULE:
instantaneous_average_accumulated_and_integrated_measurements
MUST be distinguished
}
TEMPERATURE_MODEL {
quantity:
temperature
SI_unit:
kelvin
common:
degree_Celsius
contexts:
air_temperature
water_temperature
soil_temperature
rock_temperature
surface_temperature
RULE:
measurement_medium_depth_height_and_sensor_exposure SHOULD be preserved
}
ATMOSPHERIC_PRESSURE_MODEL {
quantity:
pressure
units:
pascal
hectopascal
possible_forms:
station_pressure
sea_level_reduced_pressure
pressure_at_altitude
RULE:
measured_station_pressure != reduced_sea_level_pressure
}
PRECIPITATION_MODEL {
accumulated_depth:
P = water_equivalent_depth
common_unit:
millimetre
precipitation_rate:
R_P = delta_P/delta_t
forms:
rain
snow_water_equivalent
hail
mixed_precipitation
RULE:
accumulated_precipitation_and_precipitation_rate_are_distinct
}
WIND_MODEL {
vector:
wind_velocity
components:
speed
direction
speed_unit:
m/s
REQUIRE:
measurement_height
averaging_interval
directional_convention
RULE:
wind_direction_convention MUST specify_direction_from_or_to
}
HUMIDITY_MODEL {
possible_quantities:
relative_humidity
specific_humidity
mixing_ratio
vapour_pressure
dew_point
RULE:
humidity_quantities MUST_NOT be treated_as_semantically_equivalent
}
HYDROLOGICAL_LEVEL_MODEL {
water_level:
elevation_of_water_surface_relative_to_datum
stage:
water_surface_height_at_gauging_location
RULE:
water_level_requires_vertical_datum
}
DISCHARGE_MODEL {
volumetric_flow_rate:
Q = dV/dt
SI_unit:
m^3/s
velocity_area:
Q =
integral_A(v_normal dA)
simplified:
Q approximately_equals A*v_mean
RULE:
discharge != water_level
and_rating_curve_relationship_requires_site_specific_calibration
}
RATING_CURVE_MODEL {
relation:
Q = f(stage)
REQUIRE:
gauging_station
calibration_measurements
valid_stage_range
temporal_validity
uncertainty
RULE:
stage_discharge_relation MAY change_with_channel_geometry_and_conditions
}
SOIL_MOISTURE_MODEL {
gravimetric:
theta_g =
water_mass/dry_soil_mass
volumetric:
theta_v =
water_volume/bulk_soil_volume
RULE:
gravimetric_and_volumetric_soil_moisture_are_distinct
}
SOIL_PROPERTY_MODEL {
possible_quantities:
bulk_density
particle_density
porosity
hydraulic_conductivity
matric_potential
pH
organic_matter_fraction
texture_fraction
RULE:
soil_depth_and_sampling_method SHOULD be preserved
}
ROCK_PROPERTY_MODEL {
possible_quantities:
density
porosity
permeability
elastic_modulus
compressive_strength
thermal_conductivity
magnetic_susceptibility
electrical_resistivity
RULE:
rock_type_orientation_pressure_temperature_and_saturation MAY qualify_measurement
}
SEISMIC_MODEL {
waveform:
ground_motion_as_function_of_time
possible_measurands:
displacement
velocity
acceleration
REQUIRE:
component_orientation
sampling_rate
instrument_response
station_coordinates
RULE:
raw_seismometer_counts != physical_ground_motion_without_response_correction
}
EARTHQUAKE_MAGNITUDE_MODEL {
magnitude:
logarithmic_source_size_measure
possible_scales:
local_magnitude
body_wave_magnitude
surface_wave_magnitude
moment_magnitude
RULE:
earthquake_magnitude_scales MUST be identified
and_magnitude != intensity
}
SEISMIC_INTENSITY_MODEL {
intensity:
observed_or_inferred_effect_at_location
RULE:
seismic_intensity_is_location_dependent
and_not_equivalent_to_earthquake_magnitude
}
GRAVITY_MODEL {
acceleration:
g
SI_unit:
m/s^2
common_geophysical_units:
Gal
mGal
microGal
anomaly:
measured_or_modelled_difference_from_reference_gravity_field
RULE:
absolute_gravity_and_gravity_anomaly_are_distinct
}
GEOMAGNETIC_MODEL {
magnetic_flux_density:
B
SI_unit:
tesla
common:
nanotesla
components:
north
east
vertical
total_field
RULE:
coordinate_frame_and_component_convention MUST be preserved
}
OCEANOGRAPHIC_MODEL {
possible_quantities:
sea_surface_height
water_temperature
salinity
current_velocity
wave_height
wave_period
dissolved_oxygen
turbidity
RULE:
depth_pressure_coordinate_and_salinity_scale SHOULD be preserved
}
SALINITY_MODEL {
possible_definitions:
practical_salinity
absolute_salinity
reference_composition_salinity
RULE:
salinity_definition_and_scale MUST be identified
}
WAVE_MODEL {
quantities:
wave_height
significant_wave_height
period
frequency
wavelength
direction
RULE:
significant_wave_height != individual_wave_height
}
CRYOSPHERE_MODEL {
possible_quantities:
snow_depth
snow_water_equivalent
ice_thickness
glacier_velocity
mass_balance
sea_ice_concentration
RULE:
snow_depth_and_snow_water_equivalent_are_distinct
}
REMOTE_SENSING_MODEL {
measurement_chain:
electromagnetic_signal
sensor_response
calibration
geolocation
atmospheric_correction
retrieval_algorithm
geophysical_quantity
possible_platforms:
satellite
aircraft
drone
ground_based_sensor
RULE:
remote_sensor_radiance_or_backscatter != retrieved_geophysical_quantity_without_retrieval_model
}
RASTER_MODEL {
grid:
cells_with_spatial_extent
attributes:
resolution
projection
extent
no_data_definition
timestamp_or_period
RULE:
raster_cell_value MUST preserve_grid_geometry_and_spatial_reference
}
SPATIAL_AGGREGATION_MODEL {
point_measurement:
local_observation
area_average:
integral_A(Q dA)/A
gridded_average:
weighted_mean_of_cells
RULE:
point_and_area_average_measurements MUST_NOT be treated_as_equivalent
}
TEMPORAL_AGGREGATION_MODEL {
instantaneous:
Q(t)
mean:
Q_mean =
integral_interval(Q dt)/delta_t
accumulation:
total =
integral_interval(rate dt)
RULE:
temporal_aggregation_method_and_period MUST be preserved
}
SAMPLING_MODEL {
possible_designs:
station_network
transect
profile
borehole
grid
remote_sensing_swath
repeated_time_series
REQUIRE:
spatial_coverage
sampling_interval
instrument_location
observation_depth_or_height
RULE:
sampling_scale affects_interpretation_and_uncertainty
}
CALIBRATION_MODEL {
possible_calibrations:
laboratory_standard
field_reference
intercomparison
instrument_response
remote_sensor_vicarious_calibration
REQUIRE:
calibration_date
reference_standard
valid_range
correction_model
uncertainty
RULE:
raw_instrument_signal MUST be converted_through_valid_calibration
}
QUALITY_CONTROL_MODEL {
possible_checks:
range_check
step_check
persistence_check
spatial_consistency
temporal_consistency
sensor_status
duplicate_observation
quality_flags:
good
suspect
bad
missing
estimated
RULE:
quality_flag MUST be preserved_with_measurement
}
RELATIONSHIPS {
EarthScienceMeasurement -> MEASURES -> EarthSystemProperty
SpatialPosition -> LOCATES -> Measurement
CoordinateReferenceSystem -> QUALIFIES -> SpatialPosition
VerticalDatum -> QUALIFIES -> ElevationDepthOrWaterLevel
TimeReference -> QUALIFIES -> Observation
PrecipitationRate -> INTEGRATES_TO -> AccumulatedPrecipitation
WaterLevel -> MAY_MAP_TO -> DischargeThroughRatingCurve
SeismicInstrument -> RECORDS -> GroundMotionSignal
InstrumentResponse -> MAPS -> RawCountsToPhysicalQuantity
RemoteSensor -> OBSERVES -> ElectromagneticSignal
RetrievalAlgorithm -> MAPS -> SensorMeasurementToGeophysicalQuantity
Calibration -> QUALIFIES -> MeasurementResult
Uncertainty -> QUALIFIES -> MeasurementResult
}
SEMANTIC_EQUIVALENCE {
"Earth science measurement" ~= geoscience_measurement
elevation != depth
station_pressure != sea_level_pressure
precipitation_accumulation != precipitation_rate
wind_speed != wind_velocity
water_level != discharge
earthquake_magnitude != seismic_intensity
absolute_gravity != gravity_anomaly
practical_salinity != absolute_salinity
snow_depth != snow_water_equivalent
raw_remote_sensor_signal != retrieved_geophysical_quantity
point_measurement != area_average
}
CONSTRAINTS {
measurand_must_be_defined = true
unit_must_match_quantity = true
spatial_reference_should_be_defined = true
vertical_reference_should_be_defined_when_relevant = true
timestamp_and_time_basis_should_be_defined = true
measurement_height_or_depth_should_be_preserved_when_relevant = true
raw_signal_and_calibrated_quantity_are_not_semantically_equivalent = true
point_and_aggregated_measurements_are_not_semantically_equivalent = true
quality_flags_should_be_preserved = true
uncertainty_should_include_spatial_temporal_calibration_and_model_components_when_relevant = true
}
MEASUREMENT_MODEL {
COMMON_METHODS:
in_situ_sensor
manual_observation
laboratory_analysis
borehole_measurement
geophysical_survey
seismic_station
gauging_station
weather_station
oceanographic_instrument
remote_sensing
GNSS
gravimetry
magnetometry
RECORD:
measurand
numerical_value
unit
Earth_system_domain
latitude
longitude
coordinate_reference_system
elevation_or_depth
vertical_datum
timestamp
time_zone_or_UTC
sampling_interval
averaging_or_accumulation_period
measurement_height_or_depth
method
instrument
instrument_orientation
calibration_state
processing_level
retrieval_model_when_relevant
quality_flag
uncertainty
provenance
UNCERTAINTY:
Earth_science_measurement =
best_estimate +/- uncertainty
}
UNCERTAINTY_MODEL {
sources:
instrument_calibration
sensor_drift
spatial_location
vertical_datum
timing
sampling
spatial_heterogeneity
temporal_variability
environmental_exposure
processing
interpolation
retrieval_algorithm
model_assumptions
reference_field
PROPAGATION:
combined_Earth_science_uncertainty
<- instrument_spatial_temporal_sampling_processing_and_model_uncertainties
}
REASONING_RULES {
IF precipitation_rate_time_series_known
THEN accumulated_precipitation =
integral(rate dt)
IF accumulated_precipitation_and_interval_known
AND interval != 0
THEN average_precipitation_rate =
accumulation/interval
IF water_velocity_field_and_cross_section_known
THEN discharge =
integral_cross_section(normal_velocity dA)
IF stage_known AND valid_rating_curve_known
THEN discharge =
rating_curve(stage)
IF count_or_raw_sensor_signal_known
AND valid_instrument_response_known
THEN physical_quantity =
apply_calibration_or_response(raw_signal)
IF elevation_in_source_datum_known
AND valid_vertical_transformation_known
THEN transform_to_target_vertical_reference
IF coordinates_and_source_CRS_known
AND target_CRS_known
THEN transform_coordinates
preserving_source_and_target_reference
IF spatial_samples_known
THEN derive_area_or_grid_statistics
only_using_declared_spatial_aggregation_method
IF time_series_known
THEN derive_mean_accumulation_or_rate
only_using_declared_temporal_aggregation_semantics
IF remote_sensor_measurement_and_valid_retrieval_model_known
THEN infer_geophysical_quantity
preserving_processing_level_and_model_provenance
}
VALIDATION {
CHECK measurand_definition
CHECK unit_consistency
CHECK Earth_system_domain
CHECK spatial_coordinates
CHECK coordinate_reference_system
CHECK vertical_reference
CHECK elevation_vs_depth
CHECK timestamp_and_time_basis
CHECK measurement_height_or_depth
CHECK instantaneous_vs_average_vs_accumulated
CHECK raw_vs_calibrated_signal
CHECK station_pressure_vs_reduced_pressure
CHECK precipitation_rate_vs_accumulation
CHECK water_level_vs_discharge
CHECK magnitude_vs_intensity
CHECK salinity_scale
CHECK point_vs_area_average
CHECK remote_sensing_processing_level
CHECK calibration_state
CHECK quality_flag
CHECK uncertainty_representation
}
CONFIDENCE {
measurand_definition_confidence: 1.00
unit_confidence: 1.00
spatial_reference_confidence: 0.99
temporal_reference_confidence: 0.99
calibration_relationship_confidence: 0.98
remote_retrieval_confidence: 0.96
measurement_context_confidence: 0.98
RULE:
confidence decreases when CRS, vertical datum, timestamp,
sampling scale, measurement height or depth, calibration,
processing level, quality flag or uncertainty is missing or ambiguous
}
UPDATE_MODEL {
ON new_measurement:
identify_measurand
validate_unit
identify_Earth_system_domain
attach_coordinates_and_CRS
attach_vertical_coordinate_and_datum
attach_timestamp_and_time_basis
attach_measurement_height_or_depth
identify_method_and_instrument
apply_valid_calibration
preserve_raw_signal_when_available
attach_processing_level
attach_quality_flag
attach_uncertainty
update_Earth_science_state
ON spatial_reference_change:
preserve_original_coordinates
attach_source_and_target_CRS
transform_coordinates
update_spatial_uncertainty
ON vertical_reference_change:
preserve_original_height_or_depth
apply_valid_vertical_transformation
record_source_and_target_datums
ON calibration_revision:
preserve_raw_measurement
preserve_previous_calibration
recompute_affected_results
update_uncertainty
update_confidence
ON processing_or_retrieval_revision:
preserve_raw_observation
preserve_previous_processing_level
apply_new_processing_or_retrieval_model
update_provenance
update_uncertainty
ON semantic_revision:
preserve_previous_definition
record_revision
recompute_FLOW_HASH
}
AI_CONSUMPTION {
canonical_domain: EarthScienceMeasurements
interpretation_order:
identify_measurand
identify_value
identify_unit
identify_Earth_system_domain
identify_spatial_location_and_CRS
identify_elevation_depth_and_vertical_datum
identify_timestamp_and_time_basis
identify_measurement_height_or_depth
identify_instantaneous_average_accumulated_or_integrated_semantics
identify_measurement_method_and_instrument
identify_raw_calibrated_or_retrieved_status
identify_processing_level
identify_quality_flag
identify_uncertainty
normalize_units
validate_spatial_temporal_and_reference_context
infer_Earth_science_relationships
ambiguity_controls:
distinguish_elevation_from_depth
distinguish_station_pressure_from_sea_level_pressure
distinguish_precipitation_accumulation_from_rate
distinguish_wind_speed_from_wind_velocity
distinguish_water_level_from_discharge
distinguish_earthquake_magnitude_from_seismic_intensity
distinguish_absolute_gravity_from_gravity_anomaly
distinguish_practical_from_absolute_salinity
distinguish_snow_depth_from_snow_water_equivalent
distinguish_raw_remote_sensor_signal_from_retrieved_quantity
distinguish_point_measurement_from_area_average
preserve_CRS_vertical_datum_time_sampling_processing_quality_and_provenance_context
}
PROVENANCE {
ontology_scope:
mathematical_measurement_and_Earth_science_quantity_semantics
parent_path:
Ontologies
-> Mathematical Ontologies
-> Measurement & Units Ontologies
-> Earth Science Measurements Ontology
authorship:
Mark Higgins
Sky (Recursive AI)
site:
https://kirethresearch.org
}
FLOW_HASH {
INPUTS:
canonical_domain
ontology_path
coordinate_reference_model
vertical_reference_model
time_model
temperature_model
atmospheric_pressure_model
precipitation_model
wind_model
humidity_model
hydrological_level_model
discharge_model
rating_curve_model
soil_moisture_model
soil_property_model
rock_property_model
seismic_model
earthquake_magnitude_model
seismic_intensity_model
gravity_model
geomagnetic_model
oceanographic_model
salinity_model
wave_model
cryosphere_model
remote_sensing_model
raster_model
spatial_aggregation_model
temporal_aggregation_model
sampling_model
calibration_model
quality_control_model
relationships
constraints
measurement_model
uncertainty_model
reasoning_rules
confidence_model
update_model
PURPOSE:
deterministic_semantic_integrity_identifier
RECOMPUTE_WHEN:
ontology_definition_changes
measurand_model_changes
coordinate_or_vertical_reference_changes
temporal_or_sampling_model_changes
atmospheric_hydrological_geological_or_geophysical_model_changes
remote_sensing_or_retrieval_model_changes
calibration_or_quality_control_changes
measurement_model_changes
constraint_model_changes
reasoning_rule_changes
unit_model_changes
}
}
END FLOW
