Infrared sensors on board satellites have been widely used to collect statistics on fires, but not for fire control. Since the polar-orbiting satellites cover the northern Earth latitudes several times a day, their data are particularly suitable for detecting boreal forest fires. Currently, radiometers on board NOAA and ERS-2 satellites are used for operational fire management in Finland. Telef...

The debris circling the Earth has become an important environmental problem. In particular it creates nonnegligeable risk for spacecraft and satellites. This paper discusses a method to bound the rate of passage of objects through an arc segment in the plane of motion, given random initial conditions for the orbiting object. An advantage of the approach of this paper is that the initial conditi...

The collision on February 10, 2009 between the Iridium 33 satellite and the defunct Cosmos 2251 satellite at an altitude of 470 miles (770 km) significantly increases the amount of space debris in the region of space that is already the most crowded and has the greatest risk of collisions between orbiting objects. The debris cloud created by this collision is like a shotgun blast that threatens...

In an issue of the Wireless World magazine, back in 1945, A. C. Clarke on a letter to the editor wrote " However, I would like to close by mentioning a possibility of the remote future-perhaps half a century ahead... Three repeater stations, twelve degrees apart in the correct orbit, could give television and microwave coverage to the entire planet. " These words envisioned, before the space er...

Use of satellite data in crop growth monitoring could provide great value for regional food security assessments. By using the difference between remotely sensed crop canopy temperature and the corresponding ambient temperature at the time of the satellite overpass the daily actual rate of transpiration can be inferred. This relationship allows adjustment of the actual rate of assimilation and ...

The paper is aimed to the derivation of the simple analytical relationship between the cloud spherical albedo and the cloud reflection function in the visible. The relationship obtained can be used for the retrieval of the spherical albedo from backscattered solar light measurements performed by radiometers on geostationary and polar orbiting satellites. The example of the application of the te...

Using off-the-shelf Global Positioning System (GPS) units, we reconstruct buildings in 3D by exploiting the reduction in signal to noise ratio (SNR) that occurs when the buildings obstruct the line-of-sight between the moving units and the orbiting satellites. We measure the size and height of skyscrapers as well as automatically constructing a density map representing the location of multiple ...

In this paper a nonlinear controller technique, referred to State-Dependent Riccati Equation (SDRE), is exploited to handle relative position tracking and attitude synchronization problem involving in docking manoeuvring operations between two Earth orbiting satellites. More specifically a testbed developed by DLR-Institute of Space Systems is used for testing the proposed control algorithm. Th...