*** ## description: Summary of parameters for base and optional versions # HeavyRF Table Functions The HeavyRF package provides the following system table functions: * [`tf_rf_prop_max_signal` (directional antennas)](/heavyrf/heavyrf-table-functions#tf_rf_prop_max_signal-directional-antennas) * [`tf_rf_prop_max_signal` (isotropic antennas)](/heavyrf/heavyrf-table-functions#tf_rf_prop_max_signal-isotropic-antennas) * [`tf_rf_prop`](/heavyrf/heavyrf-table-functions#tf_rf_prop) ## tf\_rf\_prop\_max\_signal (Directional Antennas and Terrain Attenuation) Taking a set of point elevations and a set of signal source locations as input, `tf_rf_prop_max_signal` executes line-of-sight 2.5D RF signal propagation from the provided sources over a binned 2.5D elevation grid derived from the provided terarin locations, calculating the max signal in dBm at each grid cell, using the formula for free-space power loss. The terrain should contain columns for ground elevation, terrain elevation (which should be greater than or equal to the ground elevation height), and terrain attenuation in dbm per meter, specifying the degree to which signal will be attenuated if it passes between the terrain and ground elevations (i.e. through a tree or building). The RF source ID contributing the strongest signal is also outputted. When `geographic_coords` is set to `true`, `x` and `y` input coordinates are assumed to be lon/lat degrees. A best-fit conversion to a meters coordinate system is executed using the change in meters per lon/lat degree at the centroid of the input terrain, using the haversine distance formula. For convenience and optimal performance, `tf_rf_prop_max_signal` enables filter push-down by default, such that filters on the outputs `rf_source_id`, `x`, `y`, and `elevation_amsl_meters` are pushed down to the respective inputs in the `rf_sources` and `terrain_elevations` `Cursor` subqueries. ``` SELECT * FROM TABLE( tf_rf_prop_max_signal( rf_sources => CURSOR( SELECT rf_source_id, rf_source_x, rf_source_y, rf_source_z, rf_source_signal_strength_watts, rf_source_signal_frequency_mhz, rf_source_antenna_azimuth_degrees, rf_source_antenna_downtilt_degrees, rf_source_antenna_type FROM rf_sources_table ), terrain_elevations => CURSOR( SELECT x, y, ground_elevation_amsl_meters, terrain_elevation_amsl_meters, terrain_attenuation_dbm_per_meter FROM terrain_table ), antenna_patterns => CURSOR( SELECT antenna_type, antenna_gain, antenna_horizontal_degrees, antenna_horizontal_attenuation, antenna_vertical_degrees, antenna_vertical_attenuation FROM antennas_table ), rf_source_z_is_relative_to_terrain => , geographic_coords => , bin_dim_meters => , assumed_receiver_height_agl => , max_ray_travel_meters => , initial_rays_per_source => , rays_per_bin_autosplit_threshold => , min_receiver_signal_strength_dbm => , default_source_height_agl_meters => , ray_step_bin_multiple => , loop_grain_size => , ) ) ``` **Input Arguments**
ParameterCursorDescriptionData Types
rf_source_idrf_sourcesID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal.Column
rf_source_xrf_sourcesx-coordinate of the RF source, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, rf_source_x must be the same type as all other columns in the rf_sources CURSOR, excluding rf_source_z.Column
rf_source_yrf_sourcesy-coordinate of the RF source, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, rf_source_y must be the same type as all other columns in the rf_sources CURSOR, excluding rf_source_z.Column (must be same type as rf_source_x)
rf_source_z_metersrf_sourcesz-coordinate of the RF source, in meters. If rf_source_is_relative_to_terrain is set to true, meters are relative to the terrain height; for example, an input of 20 is 20 meters above ground level. Otherwise, it is absolute height above sea level; 20 is 20 meters above mean sea level (AMSL).Column
rf_source_power_wattsrf_sourcesPower in Watts (W) of the transmitting antenna. rf_source_power_watts must be the same type s all other columns in the rf_sources CURSOR, excluding rf_source_z.Column (must be same type as rf_source_x)
rf_source_freq_mhzrf_sourcesFrequency in megahertz (MHz) of the transmitting antenna. rf_source_freq_mhz must be the same type s all other columns in the rf_sources CURSOR, excluding rf_source_z.Column (must be same type as rf_source_x)
rf_source_antenna_azimuth_degreesrf_sourcesAzimuth in degrees of the transmitting antenna. rf_source_antenna_azimuth_degrees must be the same type s all other columns in the rf_sources CURSOR, excluding rf_source_z.Column (must be same type as rf_source_x)
rf_source_antenna_downtilt_degreesrf_sourcesDowntilt in degrees of the transmitting antenna. rf_source_antenna_gain must be the same type s all other columns in the rf_sources CURSOR, excluding rf_source_z.Column (must be same type as rf_source_x)
rf_source_antenna_typerf_sourcesThe type of antenna deployed. Used to lookup the antenna parameters in the antenna patterns table for the matching type entry. Must be a text type. Antenna types that are null or have no match in the antenna_patterns table will be considered omnidirectional.Column
terrain_xterrain_elevationsx-coordinate of the terrain. If geographIc_coords is true, this is assumed to be in longitude degrees, otherwise in meters. Whether FLOAT or DOUBLE, terrain_x and terrain_y must be the same type.Column
terrain_yterrain_elevationsy-coordinate of the terrain. If geographIc_coords is true, this is assumed to be in latitude degrees, otherwise in meters. Whether FLOAT or DOUBLE, terrain_x and terrain_y must be the same type.Column (must be same type as terrain_x)
ground_elevation_amsl_metersterrain_elevationsElevation of the ground, in meters above sea level. Ground is considered to fully occlude signalColumn (should be same type as terrain_elevation_amsl_meters and terrain_attenuation_dbm_per_meter)
terrain_elevation_amsl_metersterrain_elevationsMaximum elevation of the terrain (could be a building, vegetation, or the ground itself), in meters above sea level. Should be greater than or equal to ground_elevation_amsl_metersColumn (should be same type as ground_elevation_amsl_meters and terrain_attenuation_dbm_per_meter)
terrain_attenuation_dbm_per_meterterrain_elevationsAttenuation in dBm for any ray that passes above ground_elevation_amsl_meters and below terrain_elevation_amsl_meters. If type of terrain is present in the source table, the attenuation value can be looked up from another terrain attenuation table via a join.Column (should be same type as ground_elevation_amsl_meters and terrain_elevation_amsl_meters)
antenna_typeantenna_patternsAntenna type as text arguement. Used to join with rf_sources table. If antenna_type is 'default', the patterns for this type will be used for all rf_sources entry with type 'default', null, or that otherwise do not have a corresponding antenna_type entry in the antenna_patterns table.Column
antenna_gainantenna_patternsThe gain in dBm for this antenna type.Column (all numeric arguments in antenna_patterns CURSOR must be the same type)
antenna_horizontal_degreesantenna_patternsAn array specifying a set of degrees from 0 to 360, with 0 degrees representing due North, 90 degrees due East, 180 degrees due South, and 270 degrees due West. The corresponding indexed entry in the antenna_horizontal_attenuations specifies the attenuation for the degree entry. An entry will be created for each integer degree, with missing entries linearly interpolated from the closest neighbors below and above that degree. Entries can but do not have to be in order.Column (all numeric arguments in antenna_patterns CURSOR must be the same type)
antenna_horizontal_attenuationantenna_patternsAn array specifying the amount of attenuation, in dBm, for the corresponding entry with the same index in the antenna_horizontal_degrees array.Column (all numeric arguments in antenna_patterns CURSOR must be the same type)
antenna_vertical_degreesantenna_patternsAn array specifying a set of degrees from 0 to 360, with 0 degrees representing forward along the horizon along the direction of the antenna azimuth, 90 degrees directly overhead, 180 degrees in the direction opposite the antenna azimuth, and 270 degrees directly toward the ground. Entries below 0 can also be used and will be wrapped appropriately (i.e. -90 degrees = 270 degrees = directly toward the ground). The corresponding indexed entry in the antenna_vertical_attenuations specifies the attenuation for the degree entry. An entry will be created for each integer degree, with missing entries linearly interpolated from the closest neighbors below and above that degree. Entries can but do not have to be in order.Column (all numeric arguments in antenna_patterns CURSOR must be the same type)
antenna_vertical_attenuationantenna_patternsAn array specifying the amount of attenuation, in dBm, for the corresponding entry with the same index in the antenna_vertical_degrees array.Column (all numeric arguments in antenna_patterns CURSOR must be the same type)
rf_source_z_is_relative_to_terrainN/Atrue specifies that rf_source_z_meters values are the height in meters above ground level. false indicates the values are height in meters above sea level.BOOLEAN
geographic_coordsN/Atrue specifies that the input x and y arguments for RF sources and terrain elevations are in lon/lat degrees. false specifies that the data is already in a local meter coordinate system.BOOLEAN
bin_dim_metersN/AWidth and height of each binned terrain cell, which is the unit of granularity over which the RF propagation algorithm is executed.DOUBLE
assumed_receiver_height_aglN/AHeight in meters above ground_elevation_amsl_meters from the terrains_elevation cursor to measure the signal strength at, i.e. the modeled height of the receiving handset above ground.DOUBLE
max_ray_travel_metersN/AMaximum meters for which to model RF propagation from any given source. Lower values can increase performance, but potentially miss the strongest repeater for a terrain cell that is further away than the value set.DOUBLE
initial_rays_per_sourceN/ANumber of initial 2.5D rays to propagate from each source. Since rays are automatically split as needed as they radiate out from the rf source, this can be safely set to a low number such as 64 to maximize performance.BIGINT
rays_per_bin_autosplit_thresholdN/AMinimum ratio of radial rays per bin, below which the ray is split into two to ensure ray coverage of terrain bins as distance increases from the rf_source. 1.5 is a safe default value to use.DOUBLE
min_receiver_signal_strength_dbmN/AThe minimum signal strength threshold in dBm to continue propagating a signal ray from a source. Rays stop being propagated when either the distance from the source exceeds the limit set by max_ray_travel_meters, or the signal strength (as measured by free-space power loss, assuming no obstructions in the path) drops below the value set by min_receiver_signal_strength_dbm.DOUBLE
assumed_source_height_above_groundN/AThe default height in meters above ground level for a source if there is no input data in the terrain_elevations for the terrain bin in which a given rf_source lies.DOUBLE
ray_step_bin_multipleN/AThe step, in number of bins (can be fractional), used to increment the ray propagation as the ray radiates out from the RF source. Lower values of this (below 1.0) can increase accuracy of the simulation, but decrease performance. Values above 1.0 are not recommended because they can cause gaps in the output.DOUBLE
loop_grain_sizeN/AThe size in number of rays at which to parallelize over; threads will process rays in groups of at least this size. A reasonable value might be 10, although changing this number may improve performance, depending on hardware configuration.BIGINT
**Output Columns** | Name | Description | Data Type | | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------- | | `x` | x-centroid of the output terrain bin. In lon/lat degrees in longitude degrees if `geographic_coords` is set to `true`, otherwise in `meters`. | `Column` (same type as `rf_source_x` and `rf_source_y input columns`) | | `y` | y-centroid of the output terrain bin. In lon/lat degrees in longitude degrees if `geographic_coords` is set to `true`, otherwise in `meters`. | `Column` (same type as `rf_source_x` and `rf_source_y input columns`) | | `elevation_amsl_meters` | Maximum elevation of all input terrain data falling in the output XY terrain bin, in meters above sea level. | `Column` (same type as `rf_source_z_meters` input column) | | `rf_source_id` | ID of the repeater with the strongest signal for the grid cell. | `Column`(same type as RF sources ID input) | | `max_signal_strength_dbm` | The maximum signal strength in dBm for a given XY-terrain bin. | `Column` (same type as `rf_source_x` and `rf_source_y` input) | **Example** ``` SELECT rf_source_id, ST_X( ST_TRANSFORM( ST_SETSRID( ST_POINT(x, y), 32610 ), 4326 ) ) as lon, ST_Y( ST_TRANSFORM( ST_SETSRID( ST_POINT(x, y), 32610 ), 4326 ) ) as lat, CAST( CASE WHEN max_rf_signal_strength_dbm IS NULL THEN -130.0 ELSE max_rf_signal_strength_dbm END AS FLOAT ) AS rf_signal_strength_dbm FROM TABLE( tf_rf_prop_max_signal( rf_sources => CURSOR ( SELECT id, x, y, z, power_watts, freq_mhz, antenna_azimuth, antenna_downtilt, antenna_type FROM seattle_rf_sources ), terrain_elevations => CURSOR ( SELECT CAST(x_utm AS FLOAT) AS x, CAST(y_utm AS FLOAT) AS y, CAST(z + 0.0001 AS float) AS elevation FROM seattle_expanded_lidar_tiled ), antenna_patterns => CURSOR ( SELECT antenna_type, antenna_gain, antenna_horizontal_degrees, antenna_horizontal_attenuations, antenna_vertical_degrees, antenna_vertical_attenuations FROM seattle_antenna_types ), rf_source_z_is_relative_to_terrain => FALSE, geographic_coords => FALSE, bin_dim_meters => 2.0, assumed_receiver_height_agl => 2.0, max_ray_travel_meters => 2500, initial_rays_per_source => 64, rays_per_bin_autosplit_threshold => 1.5, min_receiver_signal_strength_dbm => -130.0, default_source_height_agl_meters => 20.0, ray_step_bin_multiple => 1.0, loop_grain_size => 8 ) ) ``` ![Output of RF Propagation for Seattle using HeavyRF Omniverse integration](https://files.buildwithfern.com/heavyai.docs.buildwithfern.com/heavyai/36f24b8f55e277c970d0a4bbe92121e3b80e581f08e27353dbf39b53db56377a/docs/assets/image_rf_seattle.png) ## tf\_rf\_prop\_max\_signal (Isotropic Antennas) ``` SELECT * FROM TABLE( tf_rf_prop( rf_sources => CURSOR( SELECT rf_source_id, x, y, z_meters ), rf_source_z_is_relative_to_terrain, rf_source_signal_strength_dbm, rf_source_signal_frequency_mhz terrain => CURSOR( SELECT x, y, elevation_amsl_meters ), geographic_coords, bin_dim_meters, max_ray_travel_meters, num_rays_per_source, min_receiver_signal_strength_dbm, default_source_height_agl_meters, ray_step_bin_multiple, loop_grain_size ) ) ``` Taking a set of point elevations and a set of signal source locations as input, `tf_rf_prop_max_signal` executes line-of-sight 2.5D RF signal propagation from the provided sources over a binned 2.5D elevation grid derived from the provided point locations, calculating the max signal in dBm at each grid cell, using the formula for free-space power loss. The RF source ID contributing the strongest signal is also outputted. For the short version, where `geographic_coords` defaults to true, or for the long version where `geographic_coords` is explicitly set to `true`, `x` and `y` input coordinates are assumed to be lon/lat degrees. A best-fit conversion to a meters coordinate system is executed using the change in meters per lon/lat degree at the centroid of the input terrain, using the haversine distance formula. For convenience and optimal performance, `tf_rf_prop_max_signal` enables filter push-down by default, such that filters on the outputs `rf_source_id`, `x`, `y`, and `elevation_amsl_meters` are pushed down to the respective inputs in the `rf_sources` and `terrain_elevations cursor` subqueries. **Input Arguments**
ParameterDetailsData TypeDescription
RF sourcesConsists of rf_source_id, x (RF sources), y (RF sources), and z_meters.CURSOR
rf_source_idID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal.Column | BIGINT | TEXT ENCODING DICT>
x (RF sources)x-coordinate of the RF source, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
y (RF sources)y-coordinate of the RF source, assumed to be in latitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
z_metersz-coordinate of the RF source, in meters. If rf_source_is_relative_to_terrain is set to true, meters are relative to the terrain height; for example, an input of 20 is 20 meters above ground level. Otherwise, it is absolute height above sea level; 20 is 20 meters above mean sea level (AMSL).Column | DOUBLE>
rf_source_z_is_relative_to_terraintrue specifies that z_meters values are the height in meters above ground level. false indicates the values are height in meters above sea level.BOOLEAN
rf_source_signal_strength_dbmSignal strength in dBm for all RF sources.DOUBLE
rf_source_signal_frequency_mhzFrequency in MHZ of the RF sources.DOUBLE
Terrain elevationsConsists of x (terrain elevations), y (terrain elevations), and elevation_amsl_meters.CURSOR
x (terrain elevations)x-coordinate of the terrain/building height, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
y (terrain elevations)y-coordinate of the terrain/building height, assumed to be in latitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
elevation_amsl_metersElevation of the point, in meters above sea level.Column | DOUBLE>
geographic_coordstrue specifies that the input x and y arguments for RF sources and terrain elevations are in lon/lat degrees. false specifies that the data is already in a local meter coordinate system.BOOLEAN
bin_dim_metersWidth and height of each binned terrain cell, which is the unit of granularity over which the RF propagation algorithm is executed.DOUBLE
max_ray_travel_metersMaximum meters for which to model RF propagation from any given source. Lower values can increase performance, but potentially misses the strongest repeater for a terrain cell that is further away than the value set.DOUBLE
num_rays_per_sourceNumber of 2.5D rays to propagate from each source. Higher numbers potentially provide more accurate results but can decrease performance.BIGINT
min_receiver_signal_strength_dbmThe minimum signal strength threshold in dBm to continue propagating a signal ray from a source. Rays stop being propagated when either the distance from the source exceeds the limit set by max_ray_travel_meters, or the signal strength (as measured by free-space power loss, assuming no obstructions in the path) drops below the value set by min_receiver_signal_strength_dbm.DOUBLE
**Outputs** A table of grid cells of width and height `bin_dim_meters` along with the maximum signal strength from any one repeater at that cell, and the ID of the repeater with the strongest signal. | Parameter | Details | | | ------------------------- | ------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------- | | `x` | x-centroid of the output bin, in lon/lat degrees. | `Column` (same type as RF sources input) | | `y` | y-centroid of the output bin, in lon/lat degrees. | `Column`(same type as RF sources input) | | `elevation_amsl_meters` | Maximum elevation of all input terrain data falling in the output bin, in meters above sea level. | `Column` (same type as terrain elevations input) | | `rf_source_id` | ID of the repeater with the strongest signal for the grid cell. | `Column`(same type as RF sources ID input) | | `max_signal_strength_dbm` | The maximum signal strength in dBm for a given terrain bin. | `Column` (same type as RF sources coordinates input) |
**Input Arguments**
ParameterDetailsDescription
RF sourcesConsists of rf_source_id, x (RF sources), y (RF sources), and z_meters.CURSOR
rf_source_idID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal.INT | BIGINT | TEXT ENCODING DICT
x (RF sources)x-coordinate of the RF source. If geographic_coords is set to true, assumed to be longitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
y (RF sources)y-coordinate of the RF source. If geographic_coords is set to true, assumed to be latitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
z_metersz-coordinate of the RF source, in meters. If rf_source_is_relative_to_terrain is set to true, meters are relative to the terrain height; for example, an input of 20 is 20 meters above ground level. Otherwise, it is absolute height above sea level; 20 is 20 meters above mean sea level (AMSL).FLOAT | DOUBLE
rf_source_z_is_relative_to_terraintrue specifies that z_meters values are the height in meters above ground level. false indicates the values are height in meters above sea level.BOOLEAN
rf_source_signal_strength_dbmSignal strength in dBm for all RF sources.DOUBLE
rf_source_signal_frequency_mhzFrequency in MHZ of the RF sources.DOUBLE
Terrain elevationsConsists of x (terrain elevations), y (terrain elevations), and elevation_amsl_meters.CURSOR
x (terrain elevations)x-coordinate of the terrain/building height. If geographic_coords is set to true, assumed to be longitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
y (terrain elevations)y-coordinate of the terrain/building height. If geographic_coords is set to true, assumed to be latitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
elevation_amsl_metersElevation of the point, in meters above sea level.FLOAT | DOUBLE
geographic_coordstrue specifies that the input x and y arguments for RF sources and terrain elevations are in lon/lat degrees. false specifies that the data is already in a local meter coordinate system.BOOLEAN
bin_dim_metersWidth and height of each binned terrain cell, which is the unit of granularity over which the RF propagation algorithm is executed.DOUBLE
max_ray_travel_metersMaximum meters for which to model RF propagation from any given source. Lower values can increase performance, but potentially misses the strongest repeater for a terrain cell that is further away than the value set.DOUBLE
num_rays_per_sourceNumber of 2.5D rays to propagate from each source. Higher numbers potentially provide more accurate results but can decrease performance.BIGINT
min_receiver_signal_strength_dbmThe minimum signal strength threshold in dBm to continue propagating a signal ray from a source. Rays stop being propagated when either the distance from the source exceeds the limit set by max_ray_travel_meters, or the signal strength (as measured by free-space power loss, assuming no obstructions in the path) drops below the value set by min_receiver_signal_strength_dbm.DOUBLE
default_source_height_agl_metersThe default height in meters above ground level for a source if there is no input data in the terrain_elevations for the terrain bin in which a given rf_source lies.DOUBLE
ray_step_bin_multipleThe step used in number of bins (can be fractional) for the RF propagation simulation. Lower values of this (below 1.0) can increase accuracy of the simulation, but decrease performance. Values above 1.0 are not recommended because they can cause gaps in the output.DOUBLE
loop_grain_sizeThe size in number of rays at which to parallelize over; threads will process rays in groups of at least this size. The default value is 40; performance may improve by changing this number, depending on hardware setup.BIGINT
**Output Columns** A table of grid cells of width and height `bin_dim_meters` along with the maximum signal strength from any one repeater at that cell, and the ID of the repeater with the strongest signal.
ParameterTypeDetails
xx-centroid of the output bin, in lon/lat degrees.FLOAT | DOUBLE (same type as RF sources input)
yy-centroid of the output bin, in lon/lat degrees.FLOAT | DOUBLE(same type as RF sources input)
elevation_amsl_metersMaximum elevation of all input terrain data falling in the output bin, in meters above sea level.FLOAT | DOUBLE (same type as terrain elevations input)
rf_source_idID of the repeater with the strongest signal for the grid cell.FLOAT | DOUBLE(same type as RF sources ID input)
max_signal_strength_dbmThe maximum signal strength in dBm for a given terrain bin.FLOAT | DOUBLE (same type as RF sources coordinates input)
## tf\_rf\_prop Used for generating top-k signals where 'k' represents the maximum number of antennas to consider at each geographic location. The full relevant parameter name is strongest\_k\_sources\_per\_terrain\_bin. For example, if k is set to 3, the function will return up to three overlapping antenna signals based on their strength. In that case, if only 2 signals are present, they will be returned. and if 5 signals are actually present, only the strongest 3 will be recorded. This version of the RF function can be used in optimizing antenna placements use cases or to minimize interference. For example, you might simulate repeater antenna placements on every lampost across an area, but then only plan to keep the top-performing ones. By allowing overlaps in the initial simulation, you avoid introducing coverage gaps when dropping out antennas, while also avoiding the requirement of multiple simulations. ``` SELECT * FROM TABLE( tf_rf_prop( data => CURSOR( SELECT rf_source_id, x, y, repeater_height_meters ), rf_source_z_is_relative_to_terrain, rf_source_signal_strength_dbm, rf_source_signal_frequency_mhz data => CURSOR( SELECT x, y, elevation_amsl_meters ), bin_dim_meters, strongest_k_sources_per_terrain_bin max_ray_travel_meters, num_rays_per_source, min_receiver_signal_strength_dbm default_source_height_agl_meters ray_step_bin_multiple loop_grain_size ) ) ``` **Input Arguments**
ParameterDetailsData TypeDescription
rf_sourcesConsists of rf_source_id, x (RF sources), y (RF sources), and z_meters.CURSOR
rf_source_idID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal.Column | BIGINT | TEXT ENCODING DICT
x (RF sources)x-coordinate of the RF source, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
y (RF sources)y-coordinate of the RF source, assumed to be in latitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
repeater_height_meters.Column | DOUBLE>
rf_source_z_is_relative_to_terraintrue specifies that z_meters values are the height in meters above ground level. false indicates the values are height in meters above sea level.BOOLEAN
rf_source_signal_strength_dbmSignal strength in dBm for all RF sources.DOUBLE
rf_source_signal_frequency_mhzFrequency in MHZ of the RF sources.DOUBLE
Terrain elevationsConsists of x (terrain elevations), y (terrain elevations), and elevation_amsl_meters.CURSOR
x (terrain elevations)x-coordinate of the terrain/building height, assumed to be in longitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
y (terrain elevations)y-coordinate of the terrain/building height, assumed to be in latitude degrees. Whether FLOAT or DOUBLE, x and y must be the same type.Column | DOUBLE>
elevation_amsl_metersElevation of the point, in meters above sea level.Column | DOUBLE>
bin_dim_metersWidth and height of each binned terrain cell, which is the unit of granularity over which the RF propagation algorithm is executed.DOUBLE
num_top_sources_per_terrain_binNumber of best sources ranked by signal strength for a terrain bin to be outputted in the results.BIGINT
max_ray_travel_metersMaximum meters for which to model RF propagation from any given source. Lower values can increase performance, buy potentially misses the strongest repeater for a terrain cell that is further away than the value set.DOUBLE
num_rays_per_sourceNumber of 2.5D rays to propagate from each source. Higher numbers potentially provide more accurate results but can decrease performance.BIGINT
min_receiver_signal_strength_dbmThe minimum signal strength threshold in dBm to continue propagating a signal ray from a source. Rays stop being propagated when either the distance from the source exceeds the limit set by max_ray_travel_meters, or the signal strength (as measured by free-space power loss, assuming no obstructions in the path) drops below the value set by min_receiver_signal_strength_dbm.DOUBLE
**Outputs** A table of grid cells of width and height `bin_dim_meters` along with the maximum signal strength from any one repeater at that cell, and the ID of the repeater with the strongest signal.
ParameterDetails
terrain_bin_id
xx-centroid of the output bin, in lon/lat degrees.Column | DOUBLE> (same type as RF sources input)
yy-centroid of the output bin, in lon/lat degrees.Column | DOUBLE>(same type as RF sources input)
elevation_amsl_metersMaximum elevation of all input terrain data falling in the output bin, in meters above sea level.Column | DOUBLE> (same type as terrain elevations input)
rf_source_idID of the repeater with the strongest signal for the grid cell.Column | DOUBLE>(same type as RF sources ID input)
rf_signal_strength_dbmThe signal strength in dBm for a given terrain bin.Column | DOUBLE> (same type as RF sources coordinates input)
rf_signal_z_angle_degreesThe angle in degrees of the output bin with respect to the top-k signal source rf_source_id.Column | DOUBLE> (same type as RF sources coordinates input)
rf_source_distance_metersThe distance of the top-k signal source rf_source_id from the output bin, in meters.Column | DOUBLE> (same type as RF sources coordinates input)
**Input Arguments**
ParameterDetailsData TypeDescription
RF sourcesConsists of rf_source_id, x (RF sources), y (RF sources), and z_meters.CURSOR
rf_source_idID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal.INT | BIGINT | TEXT ENCODING DICT
x (RF sources)x-coordinate of the RF source. If geographic_coords is set to true, assumed to be longitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
y (RF sources)y-coordinate of the RF source. If geographic_coords is set to true, assumed to be latitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
repeater_height_metersFLOAT | DOUBLE
rf_source_z_is_relative_to_terraintrue specifies that z_meters values are the height in meters above ground level. false indicates the values are height in meters above sea level.BOOLEAN
rf_source_signal_strength_dbmSignal strength in dBm for all RF sources.DOUBLE
rf_source_signal_frequency_mhzFrequency in MHZ of the RF sources.DOUBLE
Terrain elevationsConsists of x (terrain elevations), y (terrain elevations), and elevation_amsl_meters.CURSOR
x (terrain elevations)x-coordinate of the terrain/building height. If geographic_coords is set to true, assumed to be longitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
y (terrain elevations)y-coordinate of the terrain/building height. If geographic_coords is set to true, assumed to be latitude degrees; otherwise, an arbitrary meters-coordinate system. Whether FLOAT or DOUBLE, x and y must be the same type.FLOAT | DOUBLE
elevation_amsl_metersElevation of the point, in meters above sea level.FLOAT | DOUBLE
bin_dim_metersWidth and height of each binned terrain cell, which is the unit of granularity over which the RF propagation algorithm is executed.DOUBLE
strongest_k_sources_per_terrain_bin
max_ray_travel_metersMaximum meters for which to model RF propagation from any given source. Lower values can increase performance, but potentially misses the strongest repeater for a terrain cell that is further away than the value set.DOUBLE
num_rays_per_sourceNumber of 2.5D rays to propagate from each source. Higher numbers potentially provide more accurate results but can decrease performance.BIGINT
min_receiver_signal_strength_dbmThe minimum signal strength threshold in dBm to continue propagating a signal ray from a source. Rays stop being propagated when either the distance from the source exceeds the limit set by max_ray_travel_meters, or the signal strength (as measured by free-space power loss, assuming no obstructions in the path) drops below the value set by min_receiver_signal_strength_dbm.DOUBLE
default_source_height_agl_metersThe default height in meters above ground level for a source if there is no input data in the terrain_elevations for the terrain bin in which a given rf_source lies.DOUBLE
ray_step_bin_multipleThe step used in number of bins (can be fractional) for the RF propagation simulation. Lower values of this (below 1.0) can increase accuracy of the simulation, but decrease performance. Values above 1.0 are not recommended because they can cause gaps in the output.DOUBLE
loop_grain_sizeThe size in number of rays at which to parallelize over; threads will process rays in groups of at least this size. The default value is 40; performance may improve by changing this number, depending on hardware setup.BIGINT
**Outputs** A table of grid cells of width and height `bin_dim_meters` along with the maximum signal strength from any one repeater at that cell, and the ID of the repeater with the strongest signal. | Parameter | Details | Data Type | | --------------------------- | ------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- | | `terrain_bin_id` | | | | `x` | x-centroid of the output bin, in lon/lat degrees. | `FLOAT` \| `DOUBLE` (same type as RF sources input) | | `y` | y-centroid of the output bin, in lon/lat degrees. | `FLOAT` \| `DOUBLE`(same type as RF sources input) | | `elevation_amsl_meters` | Maximum elevation of all input terrain data falling in the output bin, in meters above sea level. | `FLOAT` \| `DOUBLE` (same type as terrain elevations input) | | `rf_source_id` | ID of the repeater with the strongest signal for the grid cell. | `FLOAT` \| `DOUBLE`(same type as RF sources ID input) | | `rf_signal_strength_dbm` | The signal strength in dBm for a given terrain bin. | `FLOAT` \| `DOUBLE` (same type as RF sources coordinates input) | | `rf_signal_z_angle_degrees` | | | | `rf_source_distance_meters` | | |