HeavyRF Table Functions
Summary of parameters for base and optional versions
The HeavyRF package provides the following system table functions:
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 => <rf_source_is_relative_to_terrain>,
geographic_coords => <geographic_coords>,
bin_dim_meters => <bin_dim_meters>,
assumed_receiver_height_agl => <assumed_receiver_height_agl>,
max_ray_travel_meters => <max_ray_travel_meters>,
initial_rays_per_source => <initial_rays_per_source>,
rays_per_bin_autosplit_threshold => <rays_per_bin_autosplit_threshold>,
min_receiver_signal_strength_dbm => <min_receiver_signal_strength_dbm>,
default_source_height_agl_meters => <default_source_height_agl_meters>,
ray_step_bin_multiple => <ray_step_bin_multiple>,
loop_grain_size => <loop_grain_size>,
)
)
Input Arguments
Parameter | Cursor | Description | Data Types |
---|---|---|---|
rf_source_id | rf_sources | ID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal. | Column<INT | BIGINT | TEXT ENCODING DICT> |
rf_source_x | rf_sources | x-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 <FLOAT | DOUBLE> |
rf_source_y | rf_sources | y-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 <FLOAT | DOUBLE> (must be same type as rf_source_x ) |
rf_source_z_meters | rf_sources | z-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 <FLOAT | DOUBLE> |
rf_source_power_watts | rf_sources | Power 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 <FLOAT | DOUBLE> (must be same type as rf_source_x ) |
rf_source_freq_mhz | rf_sources | Frequency 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 <FLOAT | DOUBLE> (must be same type as rf_source_x ) |
rf_source_antenna_azimuth_degrees | rf_sources | Azimuth 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 <FLOAT | DOUBLE> (must be same type as rf_source_x ) |
rf_source_antenna_downtilt_degrees | rf_sources | Downtilt 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 <FLOAT | DOUBLE> (must be same type as rf_source_x ) |
rf_source_antenna_type | rf_sources | The 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 <TEXT ENCODING DICT> |
terrain_x | terrain_elevations | x-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 <FLOAT | DOUBLE> |
terrain_y | terrain_elevations | y-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 <FLOAT | DOUBLE> (must be same type as terrain_x ) |
ground_elevation_amsl_meters | terrain_elevations | Elevation of the ground, in meters above sea level. Ground is considered to fully occlude signal | Column <FLOAT | DOUBLE (should be same type as terrain_elevation_amsl_meters and terrain_attenuation_dbm_per_meter ) |
terrain_elevation_amsl_meters | terrain_elevations | Maximum 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_meters | Column <FLOAT | DOUBLE (should be same type as ground_elevation_amsl_meters and terrain_attenuation_dbm_per_meter ) |
terrain_attenuation_dbm_per_meter | terrain_elevations | Attenuation 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 <FLOAT | DOUBLE (should be same type as ground_elevation_amsl_meters and terrain_elevation_amsl_meters ) |
antenna_type | antenna_patterns | Antenna 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 <TEXT ENCODING DICT> |
antenna_gain | antenna_patterns | The gain in dBm for this antenna type. | Column <FLOAT | DOUBLE> (all numeric arguments in antenna_patterns CURSOR must be the same type) |
antenna_horizontal_degrees | antenna_patterns | An 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 <FLOAT | DOUBLE> (all numeric arguments in antenna_patterns CURSOR must be the same type) |
antenna_horizontal_attenuation | antenna_patterns | An array specifying the amount of attenuation, in dBm, for the corresponding entry with the same index in the antenna_horizontal_degrees array. | Column <FLOAT | DOUBLE> (all numeric arguments in antenna_patterns CURSOR must be the same type) |
antenna_vertical_degrees | antenna_patterns | An 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 <FLOAT | DOUBLE> (all numeric arguments in antenna_patterns CURSOR must be the same type) |
antenna_vertical_attenuation | antenna_patterns | An array specifying the amount of attenuation, in dBm, for the corresponding entry with the same index in the antenna_vertical_degrees array. | Column <FLOAT | DOUBLE> (all numeric arguments in antenna_patterns CURSOR must be the same type) |
rf_source_z_is_relative_to_terrain | N/A | true 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_coords | N/A | true 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_meters | N/A | Width 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_agl | N/A | Height 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_meters | N/A | Maximum 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_source | N/A | Number 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_threshold | N/A | Minimum 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_dbm | N/A | The 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_ground | N/A | The 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_multiple | N/A | The 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_size | N/A | The 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<FLOAT | DOUBLE> (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<FLOAT | DOUBLE> (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<FLOAT | DOUBLE> (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<INT | BIGINT | TEXT ENCODING DICT> (same type as RF sources ID input) |
max_signal_strength_dbm | The maximum signal strength in dBm for a given XY-terrain bin. | Column<FLOAT | DOUBLE> (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
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.Short Version
Long Version
Parameter | Details | Data Type |
---|---|---|
RF sources | Consists of rf_source_id , x (RF sources), y (RF sources), and z_meters . | CURSOR |
rf_source_id | ID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal. | Column<INT | 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<FLOAT | 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<FLOAT | DOUBLE> |
z_meters | z-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<FLOAT | DOUBLE> |
rf_source_z_is_relative_to_terrain | true 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_dbm | Signal strength in dBm for all RF sources. | DOUBLE |
rf_source_signal_frequency_mhz | Frequency in MHZ of the RF sources. | DOUBLE |
Terrain elevations | Consists 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<FLOAT | 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<FLOAT | DOUBLE> |
elevation_amsl_meters | Elevation of the point, in meters above sea level. | Column<FLOAT | DOUBLE> |
geographic_coords | true 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_meters | Width 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_meters | Maximum 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_source | Number 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_dbm | The 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 |
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 | Text |
---|---|---|
x | x-centroid of the output bin, in lon/lat degrees. | Column<FLOAT | DOUBLE> (same type as RF sources input) |
y | y-centroid of the output bin, in lon/lat degrees. | Column<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. | Column<FLOAT | DOUBLE> (same type as terrain elevations input) |
rf_source_id | ID of the repeater with the strongest signal for the grid cell. | Column<FLOAT | DOUBLE> (same type as RF sources ID input) |
max_signal_strength_dbm | The maximum signal strength in dBm for a given terrain bin. | Column<FLOAT | DOUBLE> (same type as RF sources coordinates input) |
Parameter | Details | Text |
---|---|---|
RF sources | Consists of rf_source_id , x (RF sources), y (RF sources), and z_meters . | CURSOR |
rf_source_id | ID 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_meters | z-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_terrain | true 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_dbm | Signal strength in dBm for all RF sources. | DOUBLE |
rf_source_signal_frequency_mhz | Frequency in MHZ of the RF sources. | DOUBLE |
Terrain elevations | Consists 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_meters | Elevation of the point, in meters above sea level. | FLOAT | DOUBLE |
geographic_coords | true 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_meters | Width 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_meters | Maximum 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_source | Number 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_dbm | The 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_meters | The 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_multiple | The 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_size | The 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 |
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 | Type | Details | Text |
---|---|---|---|
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) |
max_signal_strength_dbm | | The maximum signal strength in dBm for a given terrain bin. | FLOAT | DOUBLE (same type as RF sources coordinates input) |
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
)
)
Short Version
Long Version
Input Arguments
Parameter | Details | Data Type |
---|---|---|
rf_sources | Consists of rf_source_id , x (RF sources), y (RF sources), and z_meters . | CURSOR |
rf_source_id | ID of the RF source. Used in the output for each grid cell to denote the RF source contributing the strongest signal. | Column<INT | 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<FLOAT | 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<FLOAT | DOUBLE> |
repeater_height_meters | . | Column<FLOAT | DOUBLE> |
rf_source_z_is_relative_to_terrain | true 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_dbm | Signal strength in dBm for all RF sources. | DOUBLE |
rf_source_signal_frequency_mhz | Frequency in MHZ of the RF sources. | DOUBLE |
Terrain elevations | Consists 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<FLOAT | 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<FLOAT | DOUBLE> |
elevation_amsl_meters | Elevation of the point, in meters above sea level. | Column<FLOAT | DOUBLE> |
bin_dim_meters | Width 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_bin | Number of best sources ranked by signal strength for a terrain bin to be outputted in the results. | BIGINT |
max_ray_travel_meters | Maximum 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_source | Number 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_dbm | The 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 | Text |
---|---|---|
terrain_bin_id | | |
x | x-centroid of the output bin, in lon/lat degrees. | Column<FLOAT | DOUBLE> (same type as RF sources input) |
y | y-centroid of the output bin, in lon/lat degrees. | Column<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. | Column<FLOAT | DOUBLE> (same type as terrain elevations input) |
rf_source_id | ID of the repeater with the strongest signal for the grid cell. | Column<FLOAT | DOUBLE> (same type as RF sources ID input) |
rf_signal_strength_dbm | The signal strength in dBm for a given terrain bin. | Column<FLOAT | DOUBLE> (same type as RF sources coordinates input) |
rf_signal_z_angle_degrees | The angle in degrees of the output bin with respect to the top-k signal source rf_source_id . | Column<FLOAT | DOUBLE> (same type as RF sources coordinates input) |
rf_source_distance_meters | The distance of the top-k signal source rf_source_id from the output bin, in meters. | Column<FLOAT | DOUBLE> (same type as RF sources coordinates input) |
Input Arguments
Parameter | Details | Data Type |
---|---|---|
RF sources | Consists of rf_source_id , x (RF sources), y (RF sources), and z_meters . | CURSOR |
rf_source_id | ID 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_meters | | FLOAT | DOUBLE |
rf_source_z_is_relative_to_terrain | true 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_dbm | Signal strength in dBm for all RF sources. | DOUBLE |
rf_source_signal_frequency_mhz | Frequency in MHZ of the RF sources. | DOUBLE |
Terrain elevations | Consists 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_meters | Elevation of the point, in meters above sea level. | FLOAT | DOUBLE |
bin_dim_meters | Width 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_meters | Maximum 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_source | Number 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_dbm | The 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_meters | The 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_multiple | The 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_size | The 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 |
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 |