SX line scan cameras and trigger arrays
The V and H cam ball tracking cameras are triggered from either a ceiling mounted SX line scan camera or floor mounted trigger array.
See end of this page to read about trigger arrays
What is a line scan camera ?
The GSA Golf's line scan cameras are used as triggers to the full frame cameras.
The line scan camera is not used to capture images of the ball. It is only used to detect a flying ball and trigger the full frame cameras to capture images of the ball as it flies within their field of view.
The full frame cameras are thus not running continuously but are rather in an idle state until told to take images when a ball is flying near them.
Note: The CX line scan camera is built into the ball azimuth Hcam camera casing when ordering panel style casings.
The SX line scan camera is mounted next to the overhead Hcam ball path camera. i.e. down the center line of the enclosure and facing straight down.
Connect RCA cables to the H and V cams.
Power to the SX camera is either via a supplied USB power supply or a USB cable connection to the PC (note: this USB connection on the SX is only used for power, no data is being transmitted)
RCA camera trigger cables
The V and H cam cameras are triggered from the SX line scan camera.
On the back of the SX camera (or on the side if using a multiple-channel SX camera) - you will see two RCA connectors.
Using the supplied RCA cables, connect the short one from the SX cam to the Hcam RCA connector and the long RCA cable from the SX cam to the RCA connector on the back of the Vcam
Ensure that cameras are mounted at least 5 or 6 feet from the screen!
Mounting height should not be greater than 9ft.
Line scan camera sensitivity
The above image - taken from the overhead mounted horizontal camera (Hcam) - shows 3 types of synthetic grass surfaces with varying degrees of reflectivity.
For both the Hcam and the SX line scan camera to function correctly the surface has to be non-reflective. As you can see, balls 1 and 2 in the image are very difficult to make out
due the surface reflecting too much light from the overhead lamp whereas ball 3 is clearly defined with plenty of contrast.
The line scan camera scans diagonally - left to right - in the enclosure and compares the light reflected back into the camera's image sensor with a user set reflected light level of a golf ball.
It is thus essential that there is enough contrast between the ball and the surrounding surface.
If the surface is reflective - as with ball 1 and 2 - the line scan camera's sensitivity cannot be set high enough as the underlying surface reflects nearly as much light as the ball itself.
A lot of synthetic grass surfaces on the market today reflect too much light for the cameras to function well and have to be treated to reduce the reflectivity.
One simple way to achieve this is to mask off the area directly under both the Hcam and SX line scan camera and spray with a black matt water based paint.
The grass will still appear green but will be a shade or two darker and non reflective. The area to be treated should be around 2 feet wide and 4 or 5 foot long.
All systems are supplied with a roll of non reflective carpeting. If you find that you can't set the Line Scan camera's sensitivity high enough for low shots or putts with your current turf flooring, place this carpet on the floor directly under the LS camera.
Once this is done the camera's sensitivity can be set much higher so as soon as a ball rolls or flies over it the camera will detect it and send the trigger signals to the full frame ball tracking cameras.
Floor scan area
The flooring area directly under the line scan, IR lamp and Hcam cameras must be dark and non reflective.
If you are using your own sourced turf and find that it is too reflective then it is possible to treat the floor turf area so that it is not so refective
If using the black non reflective carpet from home-depot you can use black felt tape on the edges to smooth the transition from your floor carpet to the black carpet.
Non reflective turf
Well ... not exactly super non-reflective but this new "less reflective" turf carpet works really well. i.e. rolling balls / putting are picked by the line scan camera which means all other shots will do too.
This turf padded carpet is only available in 12 ft widths and is pretty heavy so we won't be supplying it as standard with basic camera systems - i.e. the black real non-reflective carpet will be supplied -
but will be available as an optional extra and will be supplied as standard with all new full scale F series systems at the new F series prices.
Price for a 6 ft X 12ft length is currently $299 plus $99 shipping for US customers. Due to it's weight and size, export shipping costs will be in the $200 to $300 range
Line scan camera shot detection range
In the above images, Setup 1 is probably the standard setup for most users. The problem is that the ball path detection range (direction left and right) is quite limited so if balls are hit to the far left or right side of the screen, they won't be detected.
The problem is not so much the line scan camera's FOV - which has a 7 foot plus scan width at ground level - but the overhead lighting which doesn't produce a wide enough beam angle.
In Setup 2, the cameras and lighting have been moved further back towards the launch position and this increases the ball path range nicely.
The only problem is that the ball cannot be played so far ahead as before. i.e. when playing from rough and sand grass panels that are positioned ahead of the normal fairway grass tee position.
In Setup 3, the range is increased by adding more IR LED lamps so that the ball is still detected by the line scan camera when being hit far left and far right.
Recommended IR LED lamps for use with the SX Line Scan camera.
Go here to purchase if you don't already have them
The above image shows a ball trace when the camera is floor mounted with the additional floor mounted IR LED lamp. Notice how crisp, bright and sharp the ball trace is.
CX2 / CX3 setup video
Line scan camera setup problems
By far the most common issue with the line scan camera setup is the ability to set the camera's sensitivity high enough to detect low flying or rolling balls with putts.
The cause of this problem is light from the overhead lamps reflecting back into the camera from the underlying surface.
If you are experiencing this problem then follow these recommendations:
1. If using a halogen lamp next to the line scan camera, replace this with a LED IR illuminator similar to the above shown examples.
Note: all new line scan cameras are now being shipped with these.
Such IR illuminators are available on Amazon for around $ 75
2. Ensure the underlying surface is a dark non-reflective material or carpet.
A recommended carpet is : Beaullieu of America - Type: Dayside Ebony, Product 6670-890 which is available at your local Home Depot store at around $4.00 a yard.
3. Ensure that not too much ambient light is getting on the underlying surface from either other overhead lamps or from other sources.
To test for this, switch off all other overhead lamps until you have the line scan camera triggering with rolling balls.
4. While testing and setting up the line scan camera it is not necessary to have any other cameras running or any software running.
Just putt a ball under it and check to see that the LED on the side of the camera lights up for a second or two every time.
5. Ensure that the lens focus is turned fully to the right (i.e. clockwise) so that it is in the "Far" position
Focus adjustment may still be required though.
Turn focus dial in from the "far" position in 1/4 turns left while testing each time to see that the line scan camera's green light turns on with a rolling ball directly under the camera.
Use mount extensions to reduce the height of the line scan camera if your ceiling height is higher
Multiple Line scan cameras for increased range
You can also use multiple line scan cameras to increase left and right ball path range
Cameras are connected to a master multi channel LS camera that can link 4 line scan cameras together
Buy the GSA Golf Line Scan camera
With the new 400 dpi line scan chip and 70 degree wide angle range lens
Detects all putts to lob wedge shots
Price $ 450.00
Note: all CX and PX5 systems come with an SX line scan camera
Important ! Note that camera systems require that two areas within the enclosure be dark and non-reflective
and that there should not be too much ambient light getting into the enclosure. ie daylight windows near the enclosure and / or other electric lights
Line Scan camera NEWS
April 28 2017
Line Scan camera gets new wide angle 70 degree lens
All new SX Line scan cameras get a new 70 degree wide angle large format lens.
Line Scan camera gets new signal booster (op-amp)
In order to better detect balls on regular turf carpeting -instead of the usual supplied black carpet - we've added a signal booster (op-amp) to the new line scan camera.
The above oscilloscope image of the analog signal output from the line scan sensor array chip shows that the spike from a ball rolling on regular turf carpet is hardly detectable without the signal boost
whereas with the boost it is easy to detect.
The comparator reference voltage - which you adjust using the remote 10 turn dial (potentiometer) - has to be very close to ground (200 mV) without the signal boost whereas with boost it can be up to 2V.
Camera Optical Sensor Array Trigger
As an alternative to our line scan camera triggers,
you can also use optical sensor array triggers to trigger the V and H cam ball tracking cameras
The unit is 5ft in length and features 48 sensors that detect any ball passing over them.
Its advantage over the SX line scan camera trigger is that it doesn't require a non reflective floor surface
- that usually requires black or low refelctive carpet to be placed under the SX camera -
isn't affected by CTS club tracking system Xenon flashes, doesn't require any setup and works well in most lighting conditions.
The TX trigger array features 3 LED indicators at the end of the 5ft long array
The Red LED is a power indicator.
The green LED shadow indicator. i.e. if a shadow from an object is over the array then the green LED will light up.
Note that the green light is normally OFF.
If the green light is ON then this indicates that one or more of the sensors in the array is not being illuminated by the ceiling mounted IR lamp.
In this case, check that the array is directly under and centered under the IR lamp and that the IR lamp is ON (the LEDs in the lamp will glow dark red when it is ON).
The yellow LED is a trigger indicator.
When a ball or any other object passes over the array then the green LED will light up briefly and the yellow LED will light up for around 2 seconds.
Price : $ 450.00
Trigger array stance mats
Set of all 3 stance mats
2 x 3ft X 4ft left and right stance mats
plus 1 x 5ft X 5ft - front mat
$ 750- free shipping
Trigger array installation
The trigger array is floor mounted approximately halfway between the player's hitting position and the screen.
As with the SX line scan camera, an IR lamp (supplied) is mounted directly over the array at a height of 9ft
In contrast to the SX line scan camera though, the trigger array does not require any sensitivity setup.
The Hcam setup does require some small mods though.
As the trigger array will be in the FOV of the H cam camera, the right scan zone border has to be set just after the trigger array in the image
and there should be a 2 to 10 ms trigger delay set on the camera so that the image of the ball is captured
just after it passes over the array and not immediately as the ball is over the array.
Putting with the trigger array
In order to putt, either the trigger array has to embeded into raised flooring
or a 1 1/14 inch thick stance mat should be used to raise the flooring between hitting mat and the array to the height of the trigger array (1 1/4").
Note that in order to be able to putt a ball when using a trigger array the flooring has to be raised to the height of the trigger array (i.e. 1 1/4") so that the ball rolls over array.
Click the Turf Grass Flooring button to read more about flooring and how to raise flooring.
Users can either raise the entire flooring or use our 1 1/4" high stance mats to achieve this
Note that raised flooring - whether or not a trigger array is used - is required anyway as the hitting mats or trigger mats are also 1 1/4" high
Trigger array lighting
When using an IR LED lamp instead of a hologen lamp over the trigger array then the max height a ball is detected is around 4ft
In order to detect high lofted shots the player should not be more than 3 feet away from the array
Combining both the SX line scan camera and the trigger array
The TX trigger array has 3 RCA cables connected to it that allow you to combine the array with the LS camera.
Two male RCA cables coming out of the TX array are connected to the V and Hcams.
The third RCA cable is female that allows you to connect one of the SX Line Scamera RCA outputs to the TX array.
Only one output from the SX needs to be used. The other SX output is left unconnected.
This combination is recommended in situations where the player is further than 3 feet away from the trigger array and where
- due to lighting conditions and/or underlying surface reflectivity -
the line scan camera is not able to pick up lower shots and/or putts.
Note: when using an IR lamp instead of a halogen lamp over the trigger array,
the max height a ball being detected passing over the array is limited to around 4ft.
The reason for this is that IR LED lamps do not have a single light source like a halogen lamp does
but rather has numerous light sources depending on the number of IR LEDs in the lamp.
These multiple light sources cause the shadow of the ball to diffuse as the ball gets higher and thus nearer to the LED lamp
and this diffused ball shadow does not provide enough darkness and contrast for the optical sensors in the array to trigger.
With this setup, the trigger array will pick up all shots at floor level and shots lower than 4ft and the SX camera will pick up all the higher shots
Note: when using both the trigger array and the SX line scan camera, there must be a 6 to 12 inch mounting offset between the two.
i.e. the trigger array has to be either set in front or behind the SX.
This is to prevent the SX cam from picking up the light reflection from the trigger array's acrylic glass top.
Hcam trigger delays now separate for normal shots, putting and chipping when using a trigger array
When using a trigger array instead of a line-scan camera for the H and V cams, an Hcam trigger delay has to be set to prevent the trigger array casing from being captured within the image of the H cam.
As ball speeds for putting and chipping are far slower for regular shots, the trigger delay has to be greater for these putts and chip shots.
Thus there are now separate Trigger delay settings for putting and chipping.
To set in the Hcam window:
Press the P key to go into putting mode and set the trigger delay to around 80 Milli-seconds.
Press the C key to go to Chipping mode and set the trigger delay to around 20 Milli-seconds.
In normal shot mode, set the Hcam trigger array to around 4 Milli-seconds.
New "Line Scan Shot Detector" prevents inadvertent ball launches in game when retrieving balls
Occasionally inadvertent ball launches may occur when walking within the line scan area - usually to pick-up balls.
The addition of this new line scan camera placed halfway between the Hcam and hitting area will prevent this.
The "Line Scan Shot Detector" is used as a trigger gate that only allows the main line scan camera's trigger signal to pass through to the ball V and H cameras if an object passes through its FOV.
It can also be used to detect if someone is standing at or close to the hitting position and thus blocks the main trigger signal if no one is at the hitting mat.
Price: $ 499.00
New "Optical Sensor Shot Detector" prevents inadvertent ball launches in game when retrieving balls
A lower cost alternative to the line scan camera shot detection, is to use an optical sensor shot detector. This sensor is emedded in the hitting mat just in front of the ball launch position.
Up to 3 sensors can be used: one in the hitting mat for regular shots, one on green surface for putting and one for the rough or sand shots.
Price: $ 259.00