A map is a symbolic representation of selected characteristics of a place, usually drawn on a flat surface. Maps present information about the world in a simple, visual way. They teach about the world by showing sizes and shapes of countries, locations of features, and distances between places.
A good physical or digital map should be clear and easy to understand. The colour contrast and symbols should be simple and easy to understand and interpret. The style as well should be very simple without elements of complexity.
Most maps contain the same common elements: main body, legend, title, scale and orientation indicators, inset map, and source notes. Not all are necessary or appropriate for every map, but all appear frequently enough that they’re worth covering.
Title – This is the description of the map and what it contains. The title should be short and concise.
Legend: This shows what the symbols on a map mean.
The scale is the value of an actual distance on the map. It can be measured like about 1cm on the map is to 1km on the ground. This may not be appropriate if the coordinate system used does not preserve distance across the map’s extent.
Border – These are the edges of the map.
Orientation – This explains what direction is north (up, down etc).
Graticules: These are lines showing parallels of latitude and meridians of longitude for the earth. Graticules can be used to show location in geographic coordinates (degrees of latitude and longitude)
Source Notes: This tells us where the map comes from and who produced it.
A good map establishes a visual hierarchy that ensures that the most important elements are at the top and the least important are at the bottom. Typically, the top elements should consist of the main map body, the title (if this is a standalone map) and a legend (when appropriate). Ordering your maps right makes it easier for the person who will read the map to glean information in a short amount of time.
Difference between drone surveying and manual land surveying.
Surveying is a means of making relatively large-scale, accurate measurements of the Earth’s surfaces.
Land Survey involves the scientific process of measuring the dimensions of a particular area of the earth’s surface, including its horizontal distances, directions, angles, and elevations. Artificial structures, such as a road or building, may also be noted during a survey.
A Drone Survey refers to the use of a drone, or unmanned aerial vehicle (UAV), to capture aerial data with downward-facing sensors, such as RGB or multispectral cameras, and LIDAR payloads.
What are the Differences?
DRONE SURVEYING
Capturing topographic data with a drone is up to five times faster than with land-based methods and requires less manpower. With PPK geo-tagging, you also save time, as placing numerous GCPs is no longer necessary. You ultimately deliver your survey results faster and at a lower cost.
Drone maps created using good quality drone equipment, careful flight planning, commercial grade GPS ground control points and commercial grade processing software can potentially be accurate to around 2-3cm horizontally and around 5-6cm vertically.
Compared to other surveying methods, drone surveys can be completed in less time, as drones are able to cover large areas of land within a short period.
Typically, drone surveys can produce high-quality photographs and video recordings in a couple of hours.
TRADITIONAL LAND SURVEYING
While drones are agile and reliable, they can’t deal well with high winds. Drones are lightweight and small; high winds can blow them off course and make it impossible for them to get consistent readings. This is unlike traditional Land surveying equipment and instruments which are tethered to the ground.
The brick-size batteries used by drones are heavy and can get used up quickly unlike total stations which have better battery capacity. Although “the newer the model, the stronger the battery” according to Our In-house GIS Analyst, Mr Boluwatife Williams.
Traditional methods involve staff manually traversing a site to collect data points, whereas drones can collect this data with staff far away from potentially dangerous areas.
Manual surveying methods are incredibly accurate, the accuracy of the drone surveying is only threatened if the pilot is a greenhorn.
The Minister of Works and Housing, Babatunde Fashola, SAN, has called for the use of geospatial data by the military and other security agencies in the fight against insurgency in the country.
The Surveyor General of the Federation (SGoF), Mr. Abuduganiyu Adebomehin also tasked the military to fully deploy the already collated data by his office to track and monitor criminals from the position of strength of its operatives.
The duo made this charge during the 2022 Survey Coordination Conference and Meeting of the Advisory Board on Survey Training tagged; ‘Geospatal Intelligence for National Security’ held at Obafemi Awolowo University, Ile-Ife, Osun State on Wednesday, November 30, 2022.
Former Lagos state Governor Fashola, who was represented by Head of Department, Nigerian Cadastral, Coker Robert, noted that the office of the Surveyor General of the Federation (SGoF) is assigned to provide data of geospatial intelligence.
He urged the defense and security agencies to hold regular meetings with SGoF to tackle insurgency.
According to him, “With the help of Geospatial intelligence the movements and activities of the armed criminals can easily be tracked or monitored thus providing the military and all other security agencies the advantage of taking decisions and prosecuting war against criminal elements from positions of strength.“
Similarly, Adebomehin said, “Geospatial intelligence is nothing other than data in its right quantity, data saved, data disseminated, the implementation of that data in all spheres of life is what we have gathered to discuss and how it can be of importance to the nation as a whole and we are very hopeful that insecurity will be tackled successfully. We have one or two that we have identified.
“As surveyor, I will plead and enjoin each and everyone of us to follow the Survey Coordination Act Data. When you have data and you keep data your cover and you could not give the data to relevant authority, in that quest, for the insurgence in whatever form, then, the data is useless.
“We have deployed data and you can see the changes in the warfare away from the normal numerical strength of troops. You can see that bombs are being dropped and we have not heard any complains of dropping the bombs in wrong places,” he added.
COURT INVALIDATES SECTION 5 OF LAGOS STATE SURVEY LAW
A Federal High Court sitting in Lagos has revoked Section 5 of the Lagos State Survey Law, which mandated surveyors to obtain written consent of the SurveyorSurveyor General of Lagos State before carrying out survey on state lands or any land obtained by the Lagos State Government.
Justice Daniel Osiagor of the Federal High Court in Lagos held that the Lagos State House of Assembly acted unconstitutionally in enacting the law.
The judge held that the Surveyors Council of Nigeria is the only body vested with the responsibility and authority to regulate and control survey practices and profession throughout the Federal Republic of Nigeria.
He further stated that the Surveyor General in the state does not have the power to demand and/or insist on counter-signing a survey plan prepared by a registered surveyor in Lagos state.
Justice Osiagor made the pronouncement while delivering judgement in suit number: FHC/L/CS/1789/2020, filed by seven surveyors; Adaranijo Rafiu, Kikelomo Aluko, Adedeji Olarewaju, Adams Olugbenga, Mekuleyi Samuel, Aliu Samuel and Fashina Adedapo—against the Surveyor General of Lagos State and 10 others.
Other defendants in the suit are Surveyors Council of Nigeria, Olatunbosun David, Adesina Adeleke, Akomolafe A.O, Odetunmobi O. Olufemi, Mrs Akintaro, Michael Adebisi Alonge, Surv. Egbeyemi Lateef, the Attorney General of Lagos State, Moyosore Onigbanjo, and the Attorney General of the Federation, Abubakar Malami.
The court held that the first Defendant lacked the powers to reject copies of any survey plans submitted by the plaintiffs and every other registered surveyor in Nigeria for lodgement, adding that he has no power to demand or insist on counter-signing a survey plan prepared by a Registered Surveyor.
The court also held that the Surveyor General of Lagos State lacks the powers to deny the plaintiffs or any registered surveyor consent to conduct survey on any parcel of land in Lagos State , whether owned by the Lagos State government, corporate bodies or private individuals.
HOW GIS LOCATION SHARING APP HELPED FIND A MISSING CHILD
How GIS Location Sharing App Helped Find A Missing Child
March 2020, 4-year-old Evelyn “Vardie” Sides vanished in the County area of the rural Alabama woods.
Authorities said she had been under the supervision of her septuagenarian caretaker, and walking her dog when she and the dog “just disappeared.” The caretaker called 911 and rescue teams swung into action.
Within hours, her parents and the community frantic with worry had organized a search that increased to include 400 volunteers, two helicopters, and more local authority search teams.
The volunteers trooped en masse into the woods, searching, calling out her name and that of her dog. Terrified with what they might find, scared that they may be losing time as night fell without a trace of the girl or her dog.
Hours later, there was still no sign of the little girl.
Where was four-year-old Vardie?
Prayers were said, routes were checked, paths were crossed and re-crossed but still, no one could find the beautiful little redhead angel.
Until Ken Busby was called to the scene some hours into the search.
As the county’s GIS coordinator, he had already printed out an aerial map of the surrounding area. But there was a better way to help the search effort.
He got his laptop and used live GIS to help with tracking everything in real-time.
Ken Busby contacted Esri’s Disaster Response Program (DRP) team for assistance. He requested location-sharing ArcGIS software to help him and other members of the response team coordinate their search and rescue efforts remotely and in real-time.
By the next morning, the team had access to an ArcGIS mobile app with location-sharing capabilities. It is now part of ArcGIS Field Maps.
After briefing everyone, all members of the search parties were able to download the location-sharing app to their mobile devices.
Each person that went out got a login for the app. Members of each search party showed on the map in the same color. That way, they could keep track of all the groupings
At the incident command post, the team set up monitors to display maps with real-time updates on the location of each search party. Ken Busby kept constant radio contact with the searchers to keep them on the right track.
Because of Lee County’s rural setting and wooded terrain, location sharing was vital. Using the GIS location tracking map, the command post could see in real-time where the search groups were and keep them heading in the right direction at all times.
With this technology, they were able to determine what areas the search team had covered so they didn’t end up going in circles.
They kept at it until they found footsteps in the woods on the second day.
They took pictures of the footsteps and sent them to Ken Busby who uploaded the geotagged pictures to ArcGIS Pro. From there, the response team was able to map the girl’s direction of travel based on the photo locations and ascertain where she had likely gone.
Both GIS mapping and location sharing capabilities allowed the search and rescue team to home in on a specific area of interest.
This proved to be a turning point for the search effort.
By narrowing the search area, the team was able to locate the girl and her dog on the third day.
Thankfully, they were unharmed. Little Vardie was reunited with her family and taken to the hospital for checks.
Although previously unfamiliar with the location sharing app, its ease of use and the quick response from Esri’s DRP team enabled the search and rescue team to speedily implement this new capability into its emergency operation.
The story above is just one example of the capabilities of GIS when put into total use. It can help security agencies locate people and objects in real-time. Help solve complex cases or just like in the case above, reunite families.
