Utilizing Airborne LiDAR and UAV Photogrammetry Techniques in Local Geoid Model Determination and Validation

This investigation evaluates the performance of Digital Terrain Models (DTMs) generated in different vertical datums by aerial LiDAR and UAV (Unmanned Aerial Vehicle) photogrammetry techniques, for the determination and validation of local geoid models.

Many engineering projects require the point heights referring to a physical surface, i.e., geoid, rather than an ellipsoid. When a high-accuracy local geoid model is available in the study area, the physical heights are practically obtained with the transformation of Global Navigation Satellite System (GNSS) ellipsoidal heights of the points.

Besides the commonly used geodetic methods, this study introduces a novel approach for the determination and validation of the local geoid surface models using photogrammetry. The numeric tests were carried out in the Bergama region, in the west of Turkey. Using direct georeferenced airborne LiDAR and indirect georeferenced UAV photogrammetry-derived point clouds, DTMs were generated in ellipsoidal and geoidal vertical datums, respectively.

After this, the local geoid models were calculated as differences between the generated DTMs. Generated local geoid models in the grid and pointwise formats were tested and compared with the regional gravimetric geoid model (TG03) and a high-resolution global geoid model (EIGEN6C4), respectively. In conclusion, the applied approach provided sufficient performance for modeling and validating the geoid heights with centimeter-level accuracy. 

Read more at https://www.researchgate.net/publication/344146054_Utilizing_Airborne_LiDAR_and_UAV_Photogrammetry_Techniques_in_Local_Geoid_Model_Determination_and_Validation

The Face of the Bubbling Armed UAV Industry

The extensive use of UAVs by the US in Iraq and Afghanistan has raised debates over issues like civilian deaths, international law, efficacy of strikes and deterrence.

The Israeli Air Force used a weaponized drone, the Pioneer, in the 1982 war in Lebanon which impressed US for increased UAV procurement and research. Nineteen years after, the 9\11 terrorist attack created a new demand to hunt down terrorists in remote areas of Afghanistan and Pakistan.

Today, the US uses three types of drones built by General Atomics with offensive capabilities: the MQ-1 Predator, the MQ-1C Sky Warrior, and the MQ-9 Reaper. The US military uses them in two broad ways: Reconnaissance and hunter-killer missions.

Drone surveillance and attack capabilities have been effective psychologically as fear keeps also plays a major part. While drone attacks are the most effective weapon against terrorism, its net effects are difficult to judge. The presence of armed drones is a reality of the modern battlefield, but only a limited group of countries has the technological ability to produce them or the military capacity to operate them.

Currently, US and China export armed drones, and Israel is in the vicinity. As Russia, Turkey, South Korea and others join the market, a surge in globally available systems for a fruitful market could lead to a new dangerous era.

(Read more...)

Bayraktar UAV Now Deployed By Turkish Police

The Turkish National Police is now putting the Bayraktar TB2 Tactical Unmanned Aerial Vehicle (UAV) into service. The Bayraktar TB2, which was developed and produced in Turkey, is used in terrorist operations in the country’s eastern and southeastern Anatolia regions. The Bayraktar TB2 proved its accuracy during shooting tests made with integrated national missiles in April.

Turkey plans to design R-UAV for ships

Undersecretary of Defence Industries (SSM-Savunma Sanayi Müsteşarlığı) will soon announce a project for 24 Rotary Wing UAV's which will be used by Turkish Navy. R-UAV planned to have a Maximum Take Off Weight of 2 tons, will be deployed in ships and ground and will have endurance longer than navy version. Turkish Coast Guards plans to take 12 R-UAV's.

Turkey plans to equip Anka UAV with satcom capability

Turkey is planning to add satellite communication (SATCOM) capability to the domestically manufactured Anka unmanned aerial vehicle (UAV), Turkish Undersecretariat for Defense Industries (SSM) head Murad Bayar has revealed.

Bayar also informed that Turkish Engine Industries (TEI) has been ordered to develop an engine for the Anka after the original manufacturer, Avic International decided to abandon military business, and stopped deliveries in August. Anka manufacturer, Turkish Aerospace Industries (TAI) has previously ordered the Centurion engine for an initial batch of ten UAVs, but is now required to explore other options. ''Alternatively, we could consider an engine like Rotax, or modify an existing automobile engine for the Anka,'' Bayar noted, adding that the SSM is also very soon expected to sign a contract with TAI for acquisition of ten Anka systems for the Turkish Air Force.

Having completed acceptance tests in late January, the Anka medium altitude long endurance (MALE) UAV is designed for real-time image intelligence, surveillance, reconnaissance (ISR), target detection, recognition, identification and tracking missions.

Turquía: Anka y Baykar pisan el acelerador

Turquía ha completado en fechas recientes los tests de aceptación de su nuevo UAV Anka, y la fase de producción empezará en breve con un primer pedido de 30 unidades (diez sistemas) para la Fuerza Aerea Turca, que podría recibir su primera unidad a finales de 2013. Cada sistema Anka se compone de tres UAVs, mas un equipo de control terrestre, mas toda la maquinaria de operación y mantenimiento necesarios. Cada uno de estos UAVs (de aspecto, por cierto, muy parecido al de los Predator norteamericanos) pesa un total de 1.600 kilos y está propulsado por un motor de cola. Su carga de pago puede llegar a 200 kilos y su autonomía puede llegar a las 24 horas alcanzando una distancia máxima de 200 kilómetros de radio desde la unidad de control terrestre, y una altitud máxima de 7.900 metros. En cuanto a su precio unitario, no baja de 2 millones de dólares. En la actualidad, el fabricante está desarrollando ya un modelo más grande (4.000 kilos) que podrá ir armado con misiles.

 

Otra firma turca que está pegando con fuerza es Baykar. Hace un año recibió un pedido de diez unidades Bayraktar-Çaldiran con destino a Qatar, por un valor de 25 millones de dólares. A diferencia de los Anka, estos pequeños UAVs tácticos pesan tan solo 500 Kg y pueden llevar 40 kg de carga de pago.

 

Sin embargo, no son los menores de su familia: Hay tambien un modelo mini que pesa tan sólo 4.6 Kg y está propulsado por un motor eléctrico alimentado por baterías. Con una autonomía máxima de 60 minutos, puede operar en un radio de 15 Kilómetros desde la estación de control terrestre. Pequeño pero eficaz, viene siendo utilizado por el Ejército Turco desde el año 2006.

Turkey prepares to manufacture new type of UAV

The Turkish Scientific and Research Centre for Aerospace Technologies (UZAYTEM) jointly with Tusaş Motor Sanayi are preparing to manufacture a new type of unmanned aerial vehicle (UAV), the Anadolu Agency reported on Tuesday. (Read More)