The Lens of Precision: Unveiling Image-Assisted Total Stations

Chapter 1: The Dawn of IATS

In the quiet corners of surveyor’s workshops, where the scent of aged paper mingles with the hum of electronic devices, a new chapter unfolds. It’s the story of the Image-Assisted Total Stations (IATS), born at the intersection of tradition and innovation.

Our protagonist, the seasoned surveyor, once wielded a classic theodolite—a sturdy instrument with brass accents and glass eyepieces. Its purpose? To measure angles with unwavering precision. But theodolites, like old sages, had their limitations. They whispered secrets of distant peaks and hidden valleys, yet their gaze remained fixed on the horizon.

Chapter 2: The Marriage of Optics and Pixels

Enter the IATS—a hybrid creature with the heart of a theodolite and the eyes of a camera. Picture it: atop a tripod, its sleek body adorned with sensors and lenses. The surveyor adjusts the eyepiece, not to peer through glass, but to frame reality in pixels. The IATS captures the landscape—an intricate tapestry of contours, buildings, and ancient oaks.

Chapter 3: The Dance of Precision

The IATS dances to a new rhythm. It doesn’t merely measure angles; it sees them. As the surveyor pans across the skyline, the image sensor records every detail—the rusty weathervane atop the church spire, the gnarled roots of an oak tree, and the distant glimmer of a river. Theodolites of old would envy its vision.

Chapter 4: Applications Unveiled

Structural Guardianship:

The IATS patrols bridges and skyscrapers, vigilant in its duty. It detects shifts—subtle tremors or creeping deformations. Engineers pore over its data, ensuring the safety of millions who traverse those steel sinews.

Geo-Monitoring Secrets:

On rocky cliffs and unstable slopes, the IATS stands sentinel. It watches for landslides, rockfalls, and the slow erosion of time. Its images reveal the Earth’s whispers—the gradual retreat of a coastline or the sudden collapse of a sea cave.

Chapter 5: The Surveyor’s Oath

The surveyor, once tethered to the ground, now roams with purpose. Armed with the IATS, they traverse forests, traverse deserts, and traverse the boundaries of possibility. They no longer squint through eyepieces; they interpret pixels, decode landscapes, and safeguard our world.

And so, dear reader, when you glimpse a surveyor on a hilltop, know that they carry more than a tool—they carry a legacy. Theodolites may fade into memory, but the IATS? It gazes into the future, pixel by pixel, angle by angle.

The story of the first all-Ireland mapping survey 200 years ago

By Catherine Porter, UL and Keith Lilley, QUB

Maps help us to connect with our localities and many of us are familiar with maps of our local area. Historic maps in particular provide us with an important window onto our past and reveal how a place has changed over time. This year marks two centuries since the beginnings of the most detailed historic land survey of Ireland. Led by the British military led Ordnance Survey (OS), and popularised in the 1980s through Brian Friel’s play, 'Translations’, the impacts and traces of the survey on Ireland’s landscape are still seen today.

We often will turn to the first edition Ordnance Survey maps to explore the townlands of our ancestors (perhaps where our families still live today), or to figure out the location of a particular building, well or a stream, or simply explore the complex geographies and histories of the island. The historic outputs of the Ordnance Survey challenge us too in how to reconcile the complex cultural heritage and legacies of the survey with what was the most detailed country-wide large-scale mapping and survey in the world at the time.

The cultural complexities of the OS in Ireland are recorded in a variety of source materials, not just maps. In various archives, museums and repositories across Ireland and Great Britain lie correspondence, statistical accounts, drawings and sketches, and comprehensive lists of place names, providing a pre-famine record of Ireland and its population.

How and why the survey began

In early nineteenth century Ireland, land taxation based on the county cess, and earlier surveys such as the Strafford and Down surveys of the seventeenth century, were deemed an inaccurate reflection of land value. In March 1824, a Select Committee on the Survey and Valuation of Ireland was set up to explore a detailed revaluation of the land. A recommendation by Thomas Colby of the British Ordnance Survey, and later placed in charge of the Irish survey, was to incorporate townlands, and that to do so would require ‘a scale of six inches to one English mile’ (Item 1, Colby’s ‘Instructions for the Interior Survey of Ireland’, 1825).

The geographic extent of the survey also required bespoke instruments to deal with the inclement weather and to construct an accurate framework of invisible triangles from the tallest mountain tops to the smallest hills, based on a minutely accurate base line near Lough Foyle (remember your trigonometry from school!), which lies between Derry and Donegal. These same techniques and equipment were later applied to other colonial mapping exercises elsewhere in the world.

Placing boundaries

Determining the shape and size of the smallest administrative boundaries in Ireland, the townland, was far from simple. The engineer and civilian, Richard Griffith, led the ‘boundary team’ in setting out the limits and margins for every townland on the island.

As with modern property boundaries, informants often disagreed, and disputes were common. Step by step and with the assistance of local civilians, Griffith and his staff not only marked and defined known townland boundaries, but they also removed reference to the historic land divisions such as the ploughland, tate and ballibo, and created new townlands through a process of addition, amalgamation and splitting of land to form the townlands we are familiar with today.

Placing names

Core to any map are place names, but determining how these would be printed on the final cartography was a complex process. The Topographical Department led by John O’Donovan (Seán Ó Donnabháin) referred to a multitude of written authorities and travelled Ireland collecting and compiling lists of the historical forms to determine the final map presentation of place.

The details recorded by the OS field ‘name books’ are a core source material for today’s linguists and historians in charting the changes to place names and the Irish language across time and geography. Similar to townland boundaries, those authorities consulted differed in opinion and O’Donovan often sought out what he termed ‘the last of the aborigines’ (Irish speakers) to assist him in determining the place names and their histories.

Placing people

The memoir scheme, originally devised as a supplement to the maps, had military and civilian teams collect and collate details on the landscape, nature, geology, history, infrastructure, people and culture, and make ‘suggestions for improvement’. This important record of pre-famine Ireland unfortunately covers only the north of the island – the scheme was cancelled in 1840 - and shows, in particular, connections between the people and their ancient roots.

It also reveals the bias of some OS staff, especially evident in their ethnographic study of people and culture. Irish homes were frequently described as less clean and the habits of the people less virtuous, inferior, and generally ‘uncivilised’ when compared to the Scottish and English settlers who were remarked on as being industrious, neat and the cause of what was deemed as ‘improvement’ in a parish.

The complex cultural histories and legacies of the OS in Ireland cannot be denied, but nor can the achievement of the venture overall in setting down the bounds and place names for a whole country two centuries ago.

From late June 2024, there will be the opportunity to explore four of the key OS source materials through a free online resource developed by researchers based at the University of Limerick and Queen’s University Belfast through the project, ‘OS200: Digitally Remapping Ireland’s Ordnance Survey Heritage’. More about the project, team and partners can be found at the project website or on social media.