THE RELEVANCE OF COMPUTER TO LAND SURVEY

BY

ENUNEKU ASHIBUDIKE

DEPARTMENT OF COMPUTER SCIENCE, DELTA STATE

POLYTECHNIC OGWASHI-UKU.

Abstract

Computer hardware and software is becoming more and more prevalent in

the surveying business. It is not uncommon to see instruments with

Bluetooth wireless enabled interfaces. Older RS-232 otherwise known as

the serial or parallel ports on legacy computers technology for data

download and transfer are available, however, there may be specialized

software required. Some of the more expensive total stations have special

cables; however, they are supported by a number of MS Windows

operating systems. Before considering the significant capital investment in

a total station solution, ensure there is a modern and user-friendly interface

for your preferred or specified laptop computer. If the application is going

to entail rugged conditions and marginal terrain, a wireless solution is

highly desirable.

Introduction

From ancient times man had been interested in demarcating and recording

property boundaries hence early surveying efforts were directed towards

that direction. Land survey is the technique and science of measuring and

mapping relative positions above, on or under the surface of the earth.

American Congress on Surveying and Mapping (ACSM),

In contemporary times, modern life is made possible by the efforts of

surveyors and the plans, maps and charts they help to create. For an

example, the first step for the execution of most projects, is surveying.

Hence, before the construction of roads, building, railways, etc, the

surveyor makes detailed measurements in the field and prepares the

detailed plans and charts that help the engineers to layout the alignments

of such projects.

COMPUTER APPLICATION IN LAND SURVEY

Computer applications has given a new direction in the field of surveying.

It has made work easy and quick. As it requires 20% time compared to the

convetional way, also energy used by the human resource is very less.

Computer applications has made surveying to be very accurate. As in

modern world there is need to do fast and accurate work and it will never

be accomplished without computers.

Below are some of the softwares use in land surveying.

Total Station

A Total Station is an electronic instrument use in modern surveying to

determine angles and distances from the instrument to points to be

surveyed. Total stations employ a combination of lasers and prisms to

record digital readings of the measurement in a computer. Total stations

are suitable for survey requirements over large distances, particularly over

large terrain. The results of total station on such environment are more

accurate.

Total stations are one of the most advanced instruments used by surveyors.

A total station combines the theodolite, EMD and adds a computer

processor. The device is able to measure distances, horizontal and vertical

angles and slope distances. The data can then be instantly displayed on an

LCD screen for the surveyor to review. Storage of the data can be

transferred to external devices, such as flash drives, and be viewed on

personal computers.

Applications of total station

Total stations are mainly used by land surveyors and Civil Engineers,

either to record features as in Topographic Surveying or to set out features

(such as roads, houses or boundaries). They are also used by archaeologists

to record excavations and by police, crime scene investigators, private

accident reconstructionists and insurance companies to take measurements

of scenes.

Office Sync:

Office Sync: is a convenient and reliable wireless data transfer technology

used by people in the mobile workforce, such as land surveyors, contractors

and project managers to instantly transfers any data or files between the

jobsite and any computer in the office, or anywhere else in the world.

In the office or on site, using OfficeSync is as easy as:

1. Choose your file(s)

2. Select the destination

3. Click Send

The OfficeSync software automatically creates a wireless connection to the

Internet and

transfers the selected files to the Gateway The Gateway is a central server

and Interagent

that manages all uploads and downloads, routing job data between

authorized field

personnel and their offices. The Gateway is located in a secure data center

in Florida.

OfficeSync has three integrated software components that work together to

send and

receive files via the Gateway:

Field Connect

Job Monitor

Office Manager.

Is an easy to use application that installs on most PDAs and data collectors

used by field personnel. It automates the transfer of files to and from the

OfficeSync

Gateway. Field Connect is designed to work both online and offline, so you

can login and prepare files for transfer whenever it is convenient. If cellular

service is interrupted,

Field Connect

Field Connect will re-establish the connection and resume file transfer

automatically. The auto-upload feature enables hands-free data transfer,

which is useful while driving.

Job Monitor

Is a software component for non-administrators who only need to send and

receive files from their desktop. It provides real-time monitoring of the

OfficeSync Gateway so when files are sent from the field, Job Monitor

issues a pop-up notification. Users have the option to accept delivery of

the new data,or wait until later. On acceptance, Job Monitor will download

the files and remove them from the Gateway.

Office Manager

Is the central component of OfficeSync and can be installed on any PC

connected to the Internet. It contains all the administrative tools needed to

manage data

transfers to and from the jobsite. Office Manager is used to create new jobs,

crews,

devices and manage users. It includes a reporting feature that allows the

administrator to view all activity in the system, by customer, crew,

priority or location.

Electronic Theodolite

Theodolite: this is an electronic device that is widely used by land

surveyors for the measurement of vertical and horizontal angles for

mapping purposes.

Theodolites are mainly used for surveying applications, and have been

adapted for specialized purposes in fields like meteorology and rocket

launch technology. A modern theodolite consists of a movable telescope

mounted within two perpendicular axesthe horizontal or trunnion axis,

and the vertical axis. When the telescope is pointed at a target object, the

angle of each of these axes can be measured with great precision, typically

to seconds of arc.

The theodolite is set on top of a tripod and also can be used to measure

horizontal distances and determine elevations. The theodolite is used in

conjunction with a measuring device such as a taping chain or an electronic

measuring device.

Parts of a Theodolite

Like other leveling instruments, a theodolite consists of a telescope

mounted on a base. The telescope has a sight on the top of it that is used

to align the target. The instrument has a focusing knob that is used to

make the object clear. The telescope contains an eyepiece that the user

looks through to find the target being sighted. An objective lens is also

located on the telescope, but is on the opposite end as the eyepiece. The

objective lens is used to sight the object, and with the help of the mirrors

inside the telescope, allows the object to be magnified. The theodolite's

base is threaded for easy mounting on a tripod.

Advantages of Using a Theodolite

Theodolites have many advantages when compared to other leveling

instruments:

Greater accuracy.

Internal magnifying optical system.

Electronic readings.

Horizontal circles can be instantly zeroed or set to any other value.

Horizontal circle readings can be taken either to the left or right of

zero.

Repeat readings are unnecessary.

GIS (geographical information system)

GIS (geographical information system) this is a system designed to help

land surveyors to easily manage, reuse, share and analyze survey datas

saving time money and resources. GIS allows us to view, understand,

quetion, interpret, and visualize data in many was that reveal

relationships, patterns, and trends in the form of maps, globes, reports, and

charts.

GIS COMPONENTS:

The key components of GIS are a computer system, geospatial data and

users. A computer system for GIS consists of hardware, software and

methods designed to support the data capture, processing, analysis,

modeling and display of geospatial data.

A full GIS, or geographic information system, requires:

- Hardware

- Software

- Data

- People

- Methods

BENEFITS OF USING A GIS

Improve Organizational Integration:

One of the main benefits of GIS is improved management of organization

and resources. A GIS can link data sets together by common locational

data, such as addresses, which helps divisions and units share their data.

By creating a shared database, one department can benefit from the work

of anotherdata can be collected once and used many times.

Make Better Decisions:

The old adage "better information leads to better decisions" is true for GIS.

A GIS is not just an automated decision making system but a tool to

query, analyze, and map data in support of the decision making process.

Make maps:

Making maps with GIS is much more flexible than traditional manual or

automated cartography approaches. A GIS creates maps from data pulled

from databases. Existing paper maps can be digitized and translated into

the GIS as well.

The GIS-based cartographic database can be both continuous and scale

free. Map products can then be created centered on any location, at any

scale, and showing selected information symbolized effectively to highlight

specific characteristics. A map can be created anytime to any scale for

anyone, as long as you have the data.

GPS (Global Positioning System)

GPS (global positioning system) This is the newest method available to

surveyors. The system is based on constellation of 24 satellites in precise

orbits around the earth. It calculates the position of any place on the earth

surface from signals broadcast via satellite.

Basic Functions of a GPS (Global Positioning System)

Give a location: A GPS unit accurately triangulates your position by

receiving data transmissions from multiple orbiting satellites. Your

location is given in coordinates: latitude and longitude or Universal

Transverse Mercators (UTMs).

Point-to-point navigation: A location or destination is called a

"waypoint." For example, you can establish a starting waypoint at a

trailhead by using the location function. If you have the coordinates

for the campsite you're headed for (taken from a map, resource book,

website, mapping software program or other source), a GPS can give

you a straight-line, point-to-point bearing and distance to your

destination. Since trails rarely follow a straight line, the GPS'

bearing will change as you go. The indicated distance to travel will

also decrease as you approach your goal.

"Route" navigation: By combining multiple waypoints on a trail,

you can move point-to-point with intermediate bearing and distance

guides. Once you reach the first predetermined waypoint, the GPS

receiver can automatically point you to the next one or you can

manually do this.

Keep a "track:" One of the most useful functions of a GPS unit is its

ability to lay a virtual "breadcrumb trail" of where you've been,

called a track. This differs from a "route," which details where you're

going. You can configure a GPS to automatically drop "trackpoints"

over intervals of either time or distance. To retrace your steps,

simply follow the GPS bearings back through the sequence of

trackpoints.

Key Concepts

A GPS receiver does NOT replace a map and compass or the knowledge of

how to use them. Your GPS unit DOES augment and enhance your

navigational abilities with technology. But you should still always carry a

detailed map of the area and a compass.

A GPS unit is only as good as the map you use with it. The most-useful

topographical maps available in the U.S. are the 1:24,000-scale maps

published by the U.S. Geological Survey.

Practice! Before using your GPS receiver as a primary navigational tool in

unfamiliar territory, set yourself up for a successful, enjoyable trip.

Familiarize yourself with all of the unit's features and controls. Read the

owner's manual. And practice in your neighborhood or in a local park until

you're comfortable with how everything works. You can also sign up for a

GPS navigational clinic at your local REI store.

Conclusion

Use of modern technique has made human being more equipped to do more

work in less time. Modern equipments such as total stations, micro

stations, integrated with satellites using GPS and use of computer

application has made surveying more precise. Computer application has

given a new direction in the field of land survey.

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