P2P 2019 – THE METHOD

THE METHOD

ONE

A ROMER LED Rechargeable Handheld Searchlight/Torch will be secured to spirit level, that is secured to a tripod.

The height of the bottom of the tripod to the single central LED of the searchlight/torch will be 1 metre (100 cm) or less.  The height will be measured with a tape measure at the beginning of the experiment and videoed with a live time and date.

The tripod-torch will be positioned at tide level.

The mount of the tripod holding the searchlight will be moved into a position until the light can be observed by the camera at the opposite pier, at which point the position of the spirit level videoed (with a live time and date check).

As the tide level will fluctuate throughout the duration of the experiment, the distance of the tripod-torch from the tide level will be measured at the start and end of the experiment.

The mount of the tripod holding the searchlight will be moved into a position until the light can be observed by the camera at the opposite pier, at which point the position of the spirit level videoed (with a live time and date check).

 

As the tide level will fluctuate throughout the duration of the experiment, the distance of the tripod-torch from the tide level will be measured at the start and end of the experiment.

TWO

A 10,000mW Professional Green Laser Pointer will be placed and secured in the end of a 1 metre, 28 mm diameter copper pipe, which is secured to a tripod mount. A spirit level will be secured to the copper pipe.

The copper pipe is used to limit the divergence of the laser beam.

A cap at the end of the pipe with a small hole drilled in it will also limit the divergence of the laser beam.

The height of the bottom of the tripod to the laser beam will be 1 metre (100 cm) or less.  The height will be measured with a tape measure at the beginning of the experiment and videoed with a live time and date.

The tripod-laser will be positioned at tide level.

The mount of the tripod holding the laser will be moved into a position until the light can be observed by the camera at the opposite pier, at which point the position of the spirit level videoed (with a live time & date check).

The elastic straps for holding the pipe to tripod mount work, but a more secure, holding device would be more appropriate.  A suitable box type apparatus is presently being designed and built.

 

Note:

The laser at Worthing will be green and the laser at Brighton will be red.

The red laser is a 30,000mw 650nm Red Laser pointer (from Wide lasers).

An extra green laser will be at Brighton and an extra red laser will be at Worthing.

As the tide level will fluctuate throughout the duration of the experiment, the distance of the

tripod-laser from the tide level will be measured at the start and end of the experiment.

THREE

The P900 and P1000 cameras will both be tripod mounted.

The P900 camera will be positioned at Worthing and the P1000 camera will be positioned at Brighton.

The height of the bottom of the tripod to the centre of the camera lens will be 1 metre (100 cm) or less.

The height will be measured with a tape measure at the beginning of the experiment and videoed with a live time and date.

The tripod-cameras will be positioned at tide level.

An Anwenk Three Level Axis Triple Bubble Spirit Level will be secured to each camera.

Each camera will be positioned horizontal to the ground and the position of the spirit level videoed (with a live time and date check).

 

FOUR

To ensure that the correct light sources are observed a flashing code will be used.

 

The code will be two short flashes, followed by two long flashes, followed by two short flashes.

 

Each light source will perform this code if and when it can be observed.

The flashing code will be achieved not by switching the light source on and off, as the slightest movement of the laser will move the path of the beam, instead a person will use their hand to shield the beam from the sight of the observer.

Figure 1:  The position of the cameras, torches and lasers at Worthing and Brighton West pier

 

Note:
Depending upon the tide the position of the lasers, torches and cameras may vary.

The positions will be recorded.

TIDES

The experiment will take place around low tide at Worthing and Brighton West piers.

Throughout the duration of the experiment the level of the tide will change. The level of the tide will be recorded
using the website: https://www.tidetimes.org.uk/worthing-tide-times and the ADMIRALTY Tide Tables; United Kingdom, English Channel to River Humber. NP201A, Volume 1A, 2018. ISBN-13: 978-0707721477

If during the experiment, a tripod (with a mounted laser, torch or camera) is no longer in contact with the tide, it’s distance from the water’s edge and height above tide level will be videoed with a live time and date.

FIVE

The temperature (0C) of the water will be measured using the laboratory glass thermometer.

The thermometer bulb will be submerged in the water at tide level, next to one of the tripods, for at least 30 seconds and the temperature measurement videoed.

The thermometer will be wiped dry, then using the height rod as a guide, the thermometer will be held 50 cm above tide level for at least 30 seconds and until the thermometer level has stabilised (stopped moving), at which point the temperature measurement will be videoed.

The same procedure will be carried out at a height of 100, 150 and 200 cm above the tide level.

The measurement will be taken at both locations and videoed with a live time and date.

SIX

The Relative Humidity (RH%) of the air will be measured using the Preciva LCD Digital Psychrometer Mini Humidity Meter.

The humidity meter will be placed just above tide level, next to one of the tripods, for at least 30 seconds and the humidity measurement videoed.

Using the height rod as a guide, the humidity meter will be held 50 cm above tide level for at least 30 seconds at which point the humidity measurement will be videoed.

The same procedure will be carried out at a height of 100, 150 and 200 cm above the tide level.

The measurement will be taken at both locations and videoed with a live time and date.

The results will be collated in a table and displayed on the website and YouTube:

Recording the experiment:

All measurements will be videoed with a live time and date.

The possibility of lives treaming the measurements is being discussed.

Anybody present is welcome to record the measurements as well.