RADAR

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Description of tables in RADAR schema in e-Ecology database

Data model for Motion Analyses images collected with ROBIN-system for the Medium Power Radar

Originally Hans van Gasteren, May 2007

Introduction

Radar data are one of the most important measurements in Bird Avoidance System (BAS) and FlySafe project. Until now data are archived in structured files instead of in a database. In this document data model for Motion Analysis images of the ROBIN4 system is designed, based on file structure of ROBIN4-MA images as defined in High Level Design Document of ROBIN4 (HLDD, TNO 2006). MA (Motion Analysis) images are summated images of ten radar antenna rotations and are recorded twice per hour, two radar beams per radar, 3 radars in total (equalling 12 images per hour). The data comprise all recorded radar echoes with summated intensities, plus rain clutter masks, land clutter masks and all separate objects of all recognised tracks. The huge amount of data per image (360°, 150km range, 10Mb) require a flexible database. Numbers of tracks can be as high as 15.000 tracks per image, with a mean about 1000 tracks. Per day we collect 48 images * 2 beams * 10Mb * 3 radars equipped with Robin 3Gb data. Because the database must be readily and speedily accessible, only aggregated data can be recorded in the database. Original data will have to be recorded in a file system. The level of aggregation is still under debate, as the database should also allow a certain level of reanalysis. It is not desirable to store all original recorded echoes and raw radar data, which are the bulk of the data, in the database. Because the number of tracks is rather low (1000) for most of the images, it may be sufficient to store summaries of each track. This will lead to an estimated data reduction of 90%. In the near future, already during precursor phase of FlySafe project, bird echo tracks will be recorded continuously. This means that if we want to store individual tracks, also positions of each antenna rotation is stored and database could be increasing much faster than it does now.

Data model for MA images collected by ROBIN4 system .

RADAR

The radar table contains details for the different radars.

RADAR_IDunique radar id
RADAR_NAMElogical name
LATITUDEdegrees
LONGITUDEdegrees
X_POSITIONin meters, rijksdriehoekmeting
Y_POSITIONin meters, rijksdriehoekmeting
Z_POSITIONIn meters, rijksdriehoekmeting
ALTITUDE_ANTENNAIn meters with respect to sea level
Radar type:
MIN_RANGEIn meters
MAX_RANGEIn meters
RANGE_RESOLUTIONIn meters, normal MPR 30m
AZIMUTH_RESOLUTION In radials azimuth if horizontal radar else elevation
REVOLUTION_TIMEIn seconds, normal MPR 10s
Transmitter:
MEAN_CARRIER_FREQUENCYIn GigaHz
PEAK_POWERIn dB
PULSE_LENGTHIn μS
PULSE_REPETITION_FREQUENCYIn Hz
Antenna:
TYPEcirc, rectangular, omni
VERTICAL_ILLUMINATIONuniform, parabolic, parabolic², cosec²
POLARISATION(horizontal, vertical, circular)
TRANSMITTER_GAINIn dB

COVERAGE_DIAGRAM

(for each azimuth horizontal elevation is given).

RADAR_IDReference to RADAR_ID of table RADAR
COVDIAG_ID
AZIMUTHRadians (0-2PI)
ELEVATIONRadians

BEAM

RADAR_IDReference to RADAR_ID of table RADAR
BEAM_ID
BEAM_NAME
BEAM_ELEVATIONElevation of beam (radians)
EL_BEAMWIDTHBeam width (radians) in elevation
AZ_BEAMWIDTHBeam width (radians) in azimuth

IMAGE_REQUEST

RADAR_IDReference to RADAR_ID of table RADAR
BEAM_IDReference to BEAM_ID of table BEAM
IMAGE_REQUEST_ID
WINDOW_MIN_RANGEMeasurement range (m) of window
WINDOW_MAX_RANGEmeters
WINDOW_MIN_AZIMUTHradials
WINDOW_MAX_AZIMUTHradials
Motion_analysis_parametersNote: for CMA different
RAIN_CLUTTER_MODEAutomatic, off, on
LAND_CLUTTER_MODEAutomatic, off, on
DETECTION_METHODPeak detection, threshold
MIN_TRACK_MEMBERS2 ..10
ALLOWED_INTERVAL0..9
MIN_MEMBER_SIZE1..?
MIN_SPEED5..50
MAX_SPEED5..50
ALLOWED_SPEED_DEFLECTION5..50
TANGENTIA_SPEED_DEVIATION… part of score function
RADIAL_SPEED_DEVIATION… part of score function
MASS_DEVIATION… part of score function
BONUS_SCORE_PROBABILITY… part of score function
PATH_FRACTION_THRESHOLD… part of score function
RELAXATION_FACTOR0.0..1.0 … part of score function
RANGE_RESOLUTIONCorrection with respect to default range resolution
AZIMUTH_RESOLUTIONCorrection with respect to default azimuth resolution

SUBWINDOW

The subwindow table specifies size and location of subwindows

RADAR_IDReference to RADAR_ID of table RADAR
BEAM_IDReference to BEAM_ID of table BEAM
IMAGE_REQUEST_IDReference to IMAGE_REQUEST_ID of table IMAGE_REQUEST
SUBWINDOW_ID
SUBWINDOW_MIN_RANGEmeters
SUBWINDOW_MAX_RANGEmeters
SUBWINDOW_MIN_AZIMUTHradials
SUBWINDOW_MAX_AZIMUTHradials

IMAGE_RESULT

The IMAGE_RESULT table contains references to actual images that have been recorded with the radar at different timestamps. For the Medium Power Radar normally every half hour such an image is generated. So for one RADAR/ BEAM we can expect 17520 such images a year.

RADAR_IDReference to RADAR_ID of table RADAR
BEAM_IDReference to BEAM_ID of table BEAM
IMAGE_REQUEST_IDReference to IMAGE_REQUEST_ID of table IMAGE_REQUEST
IMAGE_RESULT_ID
ACQUISITION_TIMEDate and time of request
ERROR_STATUSStatus given back by Robin-system
CORRECTION_LEVELFalse alarm rate, FAR correction factor, important value, should have own graphical representation through out the year and correlate with the weather conditions
NR_OF_TRACKSNumber of tracks in image
RAIN_MASKRain clutter mask. Area were bird detection is switched off
LAND_MASKLand clutter mask. No bird detection has been achieved in this area
IMAGEJpeg image of data (high resolution ) or georef TIFF

SUBWINDOW_RESULT

The SUBWINDOW_RESULT table contains values for all the subwindows and for each image_result and contains some computed values where the most notable is the ROBIN_CORRECTED_DENSITY which is a measure of the bird density that can be used for warnings such as the BirdTam

RADAR_IDReference to RADAR_ID of table RADAR
BEAM_IDReference to BEAM_ID of table BEAM
IMAGE_REQUEST_IDReference to IMAGE_REQUEST_ID of table IMAGE_REQUEST
IMAGE_RESULT_IDReference to IMAGE_RESULT_ID of table IMAGE_RESULT
SUBWINDOW_IDReference to SUBWINDOW_ID of table SUBWINDOW
AREA(km²)
LAND_CL_PERC% land clutter in image
RAIN_CL_PERC% rain clutter in image
CLUTTER_PERC% land or rain clutter in image
TOTAL_MASS_DENSITY Total mass density per km², before MA
LAND_MASS_DENSITY Mass density per km², after MA in land clutter mask
RAIN_MASS_DENSITY Mass density per km², after MA in rain clutter mask
CLUTTER_MASS_DENSITY Mass density per km², after MA in rain or land clutter mask
BIRD_MASS_DENSITYMass density per km² of bird tracks
BIRD_ECHO_DENSITYMean bird echo density per km²
BIRD_MEAN_DIRECTIONMean direction of all bird tracks in sub-window (radians)
BIRD_MEAN_SPEEDMean speed of all bird tracks in sub-window (m/s)
MEAN_SPEED_VECTOR_RHOMean speed value added as vector
MEAN_SPEED_VECTOR_PHIMean speed direction added as vector
MEAN_BIRD_VECTOR ( sum(cos(alpha[i]) )^2 + sum(sin(alpha[i]) )^2 ) / n
STANDARD_DEVIATION_BIRD_SPEEDstandard deviation BIRD_MEAN_SPEED
NNumber of echos in subwindow
ROBIN_CORRECTED_DENSITYCorrected density
ROBIN_CORRECTED_QUALITYQuality parameter associated with the ROBIN_CORRECTED_DENSITY

The BIRD_MEAN_DIRECTION is the directional mean of the direction of all bird tracks in the subwindow. ( atan2(sum(sin(direction)) / N, sum(sin(direction)) / N) )

The BIRD_MEAN_SPEED is just the average speed of the birds in the subwindow. The STANDARD_DEVIATION_BIRD_SPEED is the standard deviation for this BIRD_MEAN_SPEED.

The MEAN_BIRD_VECTOR is a measure of whether the birds fly in the same direction. MEAN_BIRD_VECTOR = SQRT(sum(sin(direction)) /N + sum(cos(direction)) /N)

If this value is 1 they all fly in the same direction. If it is zero they all fly in opposite directions.

In addition the mean speed is also calculated as vector with the results in rho and phi in MEAN_SPEED_VECTOR_RHO and MEAN_SPEED_VECTOR_PHI.

Details for the calculations of the ROBIN_CORRECTED_DENSITY and ROBIN_CORRECTED_QUALITY are in Robin subwindow density/quality_calculations.

TRACK_RESULT

The TRACK_RESULT table contains tracks of birds that have been detected by the ROBIN4 system. It also contains as arrays all the different points in a track data. That data used to be in the TRACK_OBJECT table. The TRACK_RESULT table is a master table and the real data is contained in the inherited tables TRACK_RESULT<YEAR><MONTH>. Otherwise the TRACK_RESULT table would become too big.


RADAR_IDReference to RADAR_ID of table RADAR
BEAM_IDReference to BEAM_ID of table BEAM
IMAGE_REQUEST_IDReference to IMAGE_REQUEST_ID of table IMAGE_REQUEST
IMAGE_RESULT_IDReference to IMAGE_RESULT_ID of table IMAGE_RESULT
TRACK_RESULT_ID
DATE_TIMEStarttime (date + time) of track (for MA equal to ACQUISITION TIME, for CMA different)
TRACK_RANGEStart position of track (m)
TRACK_AZIMUTHStart position of track (radians)
TRACK_MASSMean mass of bird track
TRACK_SPEEDMean speed of bird track (m/s)
TRACK_DIRECTIONMean direction of bird track (radians)
TRACK_OBJECTSNumber of objects in track (0 – 10)
TRACK_SOURCEMA / CAM
OBJECT_LATITUDEArray of latitude position of object
OBJECT_LONGITUDEArray of longitude position of object
OBJECT_MASSArray of mass (reflection) of object
OBJECT_SIZEArray of size of object
OBJECT_RHOArray of rho coordinate of object
OBJECT_PHIArray of phi coordinate of object

Radar datamodel.png

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