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Introduction

Track queries provide a comprehensive set of options to interrogate the database in order to find the movement history of all recorded vehicles. Tracks can be found based on time, location and whether they have been involved with an incident on the highway. Any tracks founds in the database can be displayed on the main display, giving their full movement path and details of each sighting.

Track Query

This query filters tracks through every possible variation, in order to select and display a specific quota of tracks (within the time period and record limitations). The track pathways appear as a white line on the PPI, but multiple tracks can be multi-coloured to differentiate them. The filter options are as follows:

Min. Sightings: minimum number of sightings a track requires before it is recorded as a track.

Breaking Condition: a comparative command that limits the results against a speed value.

Min. Speed: the speed value, either a maximum, minimum or equal to value.

Classification: classification type to filter for. Select one or more classifications to filter, clear all to search for all tracks regardless of classification.

Travelled (m): how far along the carriageway the tracks have travelled. Toggle the 🛇, ≤ and ≥ buttons to define the value.

Area Covered (m): how far the track has travelled, either horizontally or vertically along the x/y-axis. Toggle the 🛇, ≤ and ≥ buttons to define the value. Whether the value is measured on the x or y-axis depends on which is the larger 'distance'. In the examples below, the Area Covered is defined first by the distance travelled along the x-axis, and second by the distance travelled up the y-axis.

Analysis Status: the status of the recorded track. Once a track has been recorded, retrospectively a status can be applied to help categorise the track, for example it could be labelled as a genuine alarm or a nuisance alarm. This filter allows you to find tracks based on this labelling.

Radars: enables you to filter tracks based on the radar that generated them.

For distance Travelled, it is a minimum value. The results will return tracks any value larger, any values further from zero, whether negative or positive. e.g. Travelled (m): 6 would return 7, 8, 9... and - 6 would return - 7, - 8, - 9...
For Area Covered, it is a maximum value. The results will return tracks of every distance value between a positive, or negative, value and zero. e.g. Area Covered (m): 6 would return 5, 4, 3... and - 6 would return - 5, - 4, - 3..

Carriageway: specify the carriageway you wish to query. Do not specify if you wish to query all.

Rules: you may select one or more rules to filter tracks that have broken the selected rules.

Lane: specify the lane you wish to query. Do not specify if you wish to query all.

Select All Sections: selected by default, this means the query will look for tracks in all sections. Clear this check box to have the option to select specific sections.

Filter: filter range bar used to visually filter the available sections to make it easier to select the sections you want.

Sections: this option is available if not searching in all sections - select one or more sections to only find tracks which have been seen in these sections.

Results: how many results the query has returned.

Track Results

Id: unique alphanumeric identification assigned to each track.

First/Last Sighting: date and time of when the track record begins and ends.

Duration: track length in time to the nearest second.

Seen: number of sightings of the track. Given the radar rotates four times a second, the number of sightings should be roughly equivalent to x4 the track duration (if the track does not coast.)

Coasts Ratio: value that determines how much of the track period was classed as coasting.

Classification: the type of track.

Show: select this box for the track to appear on the PPI Display. Select the box next to the Show title for all the tracks in the query to appear on the PPI Display.

Track paths will be displayed on the main display when you select Show.

Selected or all track paths from the results can be displayed on the main display.

Locate: select this icon to shift the PPI Display and until the selected track's location is visible.

History: select this icon to open the Track Details window. The Track Details window contains two tabs: Sightings and Classification.

Track Details

Summary

Id: unique Id of the track.

First Sighting: the time stamp of the first sighting seen.

Last Sighting: the time stamp of the last sighting seen.

Duration: total life span of the track.

Seen: the total number of sightings seen for this track. This value directly relates to how many rows there will be in the Sightings list.

Coast Ratio: this is the ratio of coasts to genuine sightings. A high ratio would indicate the overall quality of detection for this track was poor.

Classification: the track classification the confidence level.

Deletion Reason: the reason the track was dropped and deleted

a. Deleted - this means the track was deleted because it moved outside a detection area

b. Lost - this means the track was deleted because it was lost within a detection area. This could be because line of sight was lost (i.e. it went behind a larger object) or the signal strength from the target was too low to track properly.

Areas Covered: The amount of area this track covered when moving, based on the longest measurement in either the X or Y. There is explanation at the top of this page.

Sightings

This table lists every sighting of the track that makes up the track pathway. Select Show All Details to expand the table columns. Each table column title can be selected to re-arrange the order of the sightings e.g. select Range (m) to order the tracks by their Range value. If the sighting has an alarm icon, a red circle, click on the sighting to reveal the rule(s) this sighting broke. If the track has Show selected and is visible on the PPI Display, individual sightings can be selected and highlighted within the track pathway.

Recorded Time: the time and date of each sighting.

Speed: the speed of that track per sighting.

Course: the direction of travel per sighting.

Range (m): distance of sighting from radar.

Target Surface Area (m²): distance in range x distance in azimuth of the track per sighting.

Weight: the total number of cells that make up the track per sighting.

Strength: the sum of the signal strength for each cell which makes up the target per sighting.

Adjusted Weight: the total number of cells that make up the target, taking into account that cells increase in size over range due to the radar beam width.

Adjusted Strength: the sum of the signal strength for each cell which makes up the target, taking into account that signal strength will vary with range.

Coasting: specifies if ticked which sightings were Coasting (assumed) sightings.

Classification

This tab is explained under Classification Configs.

ATI Query

This query searches through tracks looking for whether they were created. The process of creating tracks is know as Automatic Track Initiation. The results display the start point of each track returned by the query. The ATI points are displayed as green squares which are overlaid with each other. Blocks of higher colour intensity indicate a greater number of tracks have been created in these areas. The filter options are as follows:

Min. Sightings: the minimum number of sightings a track is required to have been seen to be included in the query - loosely equivalent to track length.

Classification: the type of track.

Carriageway: specify the carriageway you wish to query. Do not specify if you wish to query all.

Results: a numeric total for the results produced by the query.

Lost Query

This query searches through tracks which have been lost within the detection area. The results display the last point of all the tracks returned by the query. The Lost points are displayed as orange squares which are overlaid with each other. Blocks of higher colour intensity indicate a greater number of tracks have been lost in these areas. The filter options are as follows:

Min. Sightings: the minimum number of sightings a track is required to have been seen to be included in the query - loosely equivalent to track length.

Classification: the type of track.

Carriageway: specify the carriageway you wish to query. Do not specify if you wish to query all.

Results: a numeric total for the results produced by the query.

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