USE OF 3D GIS IN ANALYSIS OF AIRSPACE OBSTRUCTIONS A project by by Samuka D. W. F19/1461/2010 Supervisor; Dr D. N. Siriba 1
Background and Problem Statement The Airports in Kenya are the main link between Kenya and the rest of the world. The economy of Kenya is highly dependent on the Airports functioning properly and effectively. Airport safety and security comes out as one of the majorly unadhered to areas of regulations for African airports. Private developers and contractors in the neighborhoods of airports do not take into consideration these standards before erecting buildings that end up being obstruction to the navigable airspace as evidenced by demolitions rampart around the airports in kenya. 2
Airspace around the airport needs to be clear for safe take-off and landing of aircrafts. International and local regulations have been established to keep the airports secure. The International Civil Aviation Organization (ICAO), Kenya Airports Authority (KAA) and Kenya Civil Aviation Authority (KCAA) have laid out procedures and standards that are necessary in keeping the Airport airspace open enough to allow safe navigation into and out of the airport. 3
The Problem Statement; Airports generally face the challenge of protecting their airspace from encroaching development; developers, desiring to maximize their investment, frequently propose buildings of significant height and sometimes just build them without following due process; and local planning and zoning agencies often face the apparently conflicting goals of ensuring a safe operating environment for aircraft and promoting economic growth. By their very nature, airspace design, evaluation, and protection criteria are complex and technical, because aircrafts operate in three dimensions and their performance characteristics vary greatly. Kenya and specifically JKIA applies ICAO Annex 14 for Airspace obstruction standards with minor corrections done by the legal notice number 60 in 1998 of the Kenya Gazette. Using these regulations it is possible to compare the current situation on the ground with the requirements of the standards. 4
By creating a 3D spatial model of the Airport imaginary surfaces and using this, together with measurements of the buildings near JKIA airport, this project was intended to summarize the airspace requirements for the airport and enable a further analysis of the current situation by input of the building data to the system. The analysis of this will reveal buildings that penetrate the imaginary surface and therefore can be considered to be airspace obstructions. 5
WHY THE JOMO KENYATTA INTERNATIONAL AIRPORT? Jomo Kenyatta International Airport is Kenya s largest aviation Facility and busiest airport in East Africa. It is the largest of the 39 airports in Kenya. It sits on 4654 Ha of Land LR No. 21919. According to ICAO obstruction study report in 2008, it serves a daily average of 19,000 passengers from Africa, Europe and Asia. Its International Air Transport Association code is NBO, while its International Civil Airports Organization Airport Code is: HKJK. The airport is named after Jomo Kenyatta, Kenya's first president and prime minister. 6
Also, according to the air database, a total of 23 of countries are served from Jomo Kenyatta International airport. In terms of destination, the most popular country is India with 23% of the airport destinations. The Pie charts in figure 1 show the proportions in summary of the different airlines and the countries served by the JKIA. Figure 1 The Airlines and Countries served by JKIA, Courtesy of the Air Database (airdb.com) 7
The current terminal building is arranged in a semi-circular orientation and is divided into three parts: 1a, 1b, 1c, 1d and 1e used for international arrivals and departures 8
Objectives The objectives of the study were; To create a 3D Spatial Planning Model of the obstacle limitation surfaces based on airspace regulations in ArcGIS for the JKIA runway To use the 3D Spatial Planning model to identify developments that violate the guidelines and qualify to be categorized as airspace obstructions. 9
CHAPTER 2: LITERATURE REVIEW There are a several regulations, standards, evaluation criteria, and processes designed to protect the airspace surrounding airports. These are very specific to the country or state that they are implemented in. Kenya has adopted the international regulations and standards from ICAO and in addition have our own laws that supplement these international standards and regulations. This section gives an overview of the laws and practices that govern the airspace and other relevant literature concepts that were necessary in the implementation of this project. 10
2.1 THE LAWS ON AIRSPACE OBSTRUCTIONS Kenya Airports Authority Act regarding Land acquisition and obstructions i.e. Section 14 and 15 14. Powers to enter land to survey, etc. 15. Power to enter land to prevent accidents, etc. (3) Where any person erects any building which in any way interferes with the operation of any service provided by the Authority under this Act, the Authority may, unless such person has previously obtained the approval of the managing director to the erection of such building, or has modified it to the satisfaction of the managing director, apply to the High Court for an order for the demolition or modification of such building, or, as the case may require, for the payment to the Authority of the cost incurred in the resetting or replacement necessary to prevent such obstruction or danger and the court at its discretion may grant such order as it may deem fit as to the payment of compensation and costs. 11
2.2 RUNWAY DESIGNATION AND CLASSIFICATION Every runway is identified by a two-digit number, which indicates the magnetic azimuth of the runway in the direction of operations to the nearest 10. For example, a runway with a magnetic azimuth of 224 is designated and marked as "Runway 22" (for 220 ). Obviously, the identification numbers at the two ends of any given runway will differ by 18. For instance, the opposite end of Runway 22 is designated as Runway 04, and the runway may be referred to as "Runway 04/22." The current runway at JKIA is named 06/24 and has the description: 4117 x 45m, paved and lighted. Meaning that it has a length of 4117 meters (13507 ft.) and a runway Elevation 1624 meters Above Sea Level (ASL) (5327 ft.) the runway is 45 meters wide with 15 meters paved shoulders making it a code E runway that can handle wide body aircrafts including the Boeing B747. The instrument landing system is ICAO category I, meaning that it has some limitations in operation during bad weather. Rehabilitations to make the runway category II are slated to take of in April 2015 according to a press release by the Kenya Airports Authority on January 22, 2015. A second Runway is also in line to be constructed 12
Figure 3 A Google Earth image of the Runway 06/24 and the terminal 1 at the JKIA, Photo Courtesy of Google Earth 13
2.3 THE SURFACES The inner horizontal surface is a horizontal plane in an airport and its environs. It should normally be a circle whose radius depends on the type of runaway (s) available (non-instrument approach, non-precision approach, or precision approach). The conical surface projects upward at a slope of 5 percent from the periphery of the inner horizontal surface to a specified height above that surface. The approach surface, as the name suggests, protects the approach to the runway from obstructions. In planar view, it looks like a trapezoid inclined relative to the horizontal plane and may have a first section and a second section of different slopes 14
There are transitional surfaces on either side of the runway and of the approach surface which slopes upward and outwards to the height of the inner horizontal surface. The balked landing surface is also defined for precision approach runaways. A balked landing also known as a go-around, is an aborted landing of an aircraft that is on final approach for landing. The takeoff climb surface is an inclined plane intended to prevent obstructions to the paths of departing aircraft near a runway. 15
Figure 4 Obstacle Limitation surfaces, ICAO Annex 14, chapter 4, page 4-3 16
table 1 dimensions and slopes of obstacle limitation surfaces approach runways, icao annex 14, page 4-8. 17
Table 1 dimensions and slopes of obstacle limitation surfaces approach runways, icao annex 14, page 4-8, continuation 18
3. Methodology 19
4. RESULTS AND ANALYSIS Figure 4.1 views from The ArcScene model created in Sketch up 20
Figure 4.2 (a) and (b) Different views of the model 21
Figure 4.3 (a) buildings after extrusion Figure 4.3 (b) Buildings within the model 22
ANALYSIS Intersection An intersection was done for the airspace surface and the buildings surface. The output was specified to be surface for the analysis of violation. The resulting images were as follows; (a) (b) Figure 4.5 (a) and (b) intersection results, side and aerial view respective;y 23
SUMMARY OF VIOLATION The final value after export of the attribute table to excel and analyzing it, was 203 out of the 1017 digitized buildings in violation of the airspace limitation surfaces regulations A visual analysis indicate that they are towards the edges of the inner horizontal surface. 24
5. CONCLUSIONS AND RECOMMENDATIONS The objective of the creation of a 3D Spatial Planning Model of the Imaginary surfaces in ArcGIS was achieved. The main imaginary surfaces were represented on the model, this included the horizontal surface, the conical surface and the approach surfaces that were used for evaluation purposes. Calculations were necessary for the creation of some surfaces in order to bring the surfaces from a mathematical description on paper to a 3D representation. The objective of using the 3D Spatial Planning model to identify developments that do not adhere to the guidelines and qualify to be categorized as airspace obstructions was also achieved. The intersection results were used to clearly visualize and analyze the violation of airspace obstruction guidelines by the buildings around the airport. Based on the above achievements, it is concluded that the overall objective of analyzing the airspace obstruction around the airport using 3D GIS was satisfactorily achieved. 25
RECOMMENDATIONS. The 3D model would be better created and details included e.g. the complex transitional surfaces using better design software other than ArcGIS and ArcScene that the Geospatial engineering student is conversant with. I recommend software such as sketch - up and AutoCAD for the creation of advanced and detailed conical and curved approach surfaces which are able to create better surfaces and there-by allowing for better analysis. A higher resolution DEM for the Nairobi Area and more for the Machakos neighborhood of the airport would be more useful and can be used for a very precise Obstruction study of the Airport. A LIDAR dataset is also recommended for the building surfaces and with this the DEM would not have been of such a low resolution. This would also in effect solve the height estimation issue once and for all by the heights being directly getting the heights from the LIDAR data of from accurate photogrammetric height extraction. 26
RECOMMENDATIONS In similar projects in future, access to buildings proposed by individuals would be of huge importance specifically for the analysis of their effects on the airspace and their obstruction status. It is also recommended for anyone doing a similar project in future to delve deeper and focus on the details of height zoning in the ICAO regulations. This would facilitate better recommendation on whether the building or obstacle should be demolished, marked or lit better. 27
28
Thank You very Much 29