Remote Sensing Basics Page 4 of 4 Currently there are many airborne and satellite based imaging sensors flying. Click HERE to explore some examples. Other than ground-based means, there are three broad ranges of distances from the earth surface in which remote sensing images can be obtained. 1.   Sensors carried by aircraft obtain images, at heights of 500 metres to 20 kilometres, altitudes at which aerial photographs and aerial surveys are carried out. 2. Sensors carried by spacecraft and satellites that operate at altitudes of 250 to 1000 kilometres. Although spacecraft, of which are usually manned operate at an orbital altitude of approximately 250 to 300 kilometres. Reconnaissance satellites also orbit the earth within this altitudinal zone. Many remote sensing, earth resources satellites (e.g. Landsat and SPOT) and polar meteorological satellites (e.g. NOAA) operate at an average altitude of 1000 kilometres. 3. High altitude satellites operate at an orbital altitude of approximately 3600 kilometres. These are geostationary meteorological satellites (e.g. Meteosat) and they have the unique characteristic of remaining stationary with respect to the earth's surface. The following links are examples of how remote sensing is being used to in mountainous and upland areas and to monitor glaciers. Now search the web and see if you can find any further examples of its use. Click on the following links to explore the main types of remote sensing systems that can be used in studying mountain areas. Aerial Photography Satellite Imagery   | 1 | 2 | 3 | 4 | Page 4 of 4