Refer also to Satellite-related info.
Contents
Don't forget
How to measure
Beyond Europe
Space
Tracking
- Space-track.org
- Real time satellite tracking
- ISS
- ISS - Wikipedia
- involves five space agencies: the United States' NASA, Russia's Roscosmos, Japan's JAXA, Europe's ESA, and Canada's CSA
- The ISS is currently maintained in a nearly circular orbit with a minimum mean altitude of 370 km (230 mi) and a maximum of 460 km (290 mi),[391] in the centre of the thermosphere, at an inclination of 51.6 degrees to Earth's equator with an eccentricity of 0.007. This orbit was selected because it is the lowest inclination that can be directly reached by Russian Soyuz and Progress spacecraft launched from Baikonur Cosmodrome at 46° N latitude without overflying China or dropping spent rocket stages in inhabited areas.[392][393] It travels at an average speed of 28,000 kilometres per hour (17,000 mph), and completes 15.5 orbits per day (93 minutes per orbit).
- MIT coding ISS robots
- Group on Earth Observation
- RTL-Software Defined Radio based on the RTL2832U chipset, a cheap ~$30 USB dongle that offers a computer based radio scanner for receiving live radio signals. Depending on the particular model it could receive frequencies from 500 kHz up to 1.75 GHz
NASA
US SpaceX
Founded in 2002 by Elon Musk with the goal of reducing space transportation costs and to colonize Mars. Operates the Falcon 9 and Falcon Heavy rockets along with the Dragon spacecraft.
Europe, ESA, ...
Vendors and Consulting
Satellite imagery
- Satellite imagery - Wikipedia
- Five types of resolution when discussing satellite imagery in remote sensing:
- spatial resolution, defined as the pixel size of an image representing the size of the surface area (i.e. m2) being measured on the ground, determined by the sensors' instantaneous field of view (IFOV)
- spectral resolution, defined by the wavelength interval size (discrete segment of the Electromagnetic Spectrum) and number of intervals that the sensor is measuring
- temporal resolution, defined by the amount of time (e.g. days) that passes between imagery collection periods for a given surface location
- radiometric resolution, defined as the ability of an imaging system to record many levels of brightness (contrast for example) and to the effective bit-depth of the sensor (number of grayscale levels) and is typically expressed as 8-bit (0–255), 11-bit (0–2047), 12-bit (0–4095) or 16-bit (0–65,535)
- geometric resolution refers to the satellite sensor's ability to effectively image a portion of the Earth's surface in a single pixel and is typically expressed in terms of Ground sample distance, or GSD. GSD is a term containing the overall optical and systemic noise sources and is useful for comparing how well one sensor can "see" an object on the ground within a single pixel.
- GSD of Landsat is ≈30m, which means the smallest unit that maps to a single pixel within an image is ≈30m x 30m.
- The latest commercial satellite (GeoEye 1) has a GSD of 0.41 m. This compares to a 0.3 m resolution obtained by some early military film based Reconnaissance satellite such as CIA's Corona.
- EOS.com blog on free sat images
USGS/NASA Landsat
The Landsat Program is a series of Earth-observing satellites co-managed by United States Geological Survey (USGS) and NASA, and offers the longest continuous space-based record of Earth’s land in existence.
The first Landsat satellite launched on July 23, 1972.
NASA is responsible for developing the space and launch segments. They build, launch, and perform the on-orbit checkout for the Landsat satellites.
The USGS is responsible for developing the ground segment and operating the mission after launch. They manage the ground stations, conduct mission operations, and process and distribute the data acquired by the Landsat satellites. The five ground receiving stations that make up the Landsat 8 and Landsat 9 USGS Ground Network are located in Sioux Falls, South Dakota; Alice Springs, Australia (; Neustrelitz, Germany; Gilmore Creek, Alaska; and Svalbard, Norway.
Data acquired by Landsat satellites are distributed from the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota. All Landsat data are distributed by the USGS at no charge from EarthExplorer, GloVis, and the LandsatLook Viewer.
Landsat 8 and 9 Orbit Information
- Orbits the Earth in a sun-synchronous, near-polar orbit (98.2 degrees inclination).
- Altitude of 705 km (438 mi).
- Completes one Earth orbit every 99 minutes.
- 10:00 a.m. +/- 15 minutes equatorial crossing time.
- Acquires approximately 750 scenes a day.
Temporal Revisit
- 16-day repeat cycle (8-day revisit when combined).
- 185 km swath with swath overlap (or sidelap) varying from 7 percent at the equator to a maximum of approximately 85 percent at extreme latitudes.
Each satellite collects data at a 30-meter resolution for multi-spectral bands, one 15-meter panchromatic band, and 2 thermal bands.
Both Landsat 8 and 9 carry two sensors, the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS).
- OLI sensors capture nine spectral bands in the visible, near-infrared, and shortwave infrared portions of the electromagnetic spectrum.
- TIRS measures thermal radiance emitted from the land surface in two thermal infrared bands.
Spectral Characteristics
- Coastal/Aerosol Band (Band 1) senses deep blues and violets, often hard to collect since they are easily scattered by aerosols like dust and water vapor. The two main uses of this band are imaging shallow water and tracking fine particles like dust and smoke.
- Visible Light Bands (Bands 2, 3, 4) are used to make natural color images using blue, green, and red light.
- Near Infrared (Band 5), or NIR, is especially important for vegetation because growing plants reflect it – the water in their leaves scatter the wavelengths back into the sky. This enables a more precise measurement of plant health than possible with natural color.
- Shortwave Infrared (Bands 6, 7), or SWIR, are particularly useful for telling wet earth from dry earth, and for geology: rocks and soils that look similar in other bands often have strong contrasts in SWIR.
- Panchromatic (Band 8) works like black and white film. Instead of collecting visible colors separately, it combines them into one channel. It is the sharpest of all the bands, with a resolution of 15 meters (50 feet).
- Cirrus Band (Band 9) shows the least, yet it’s one of the most interesting features of Landsat 8 and Landsat 9. High, thin cirrus clouds can be hard to spot in satellite images. Both the clouds and their shadows can interfere with measurements. Landsat 8 and 9 are designed to detect these clouds by measuring light in the part of the electromagnetic spectrum where the clouds are most visible.
- Two Thermal Infrared Bands (Bands 10, 11), or TIRS, see heat. Instead of measuring the temperature of the air, like weather stations do, they report on the temperature of the ground itself, which is often hotter.
USGS' EarthExplorer
The EarthExplorer (EE) user interface is an online search, discovery, and ordering tool developed by the USGS. EE supports the searching of satellite, aircraft, and other remote sensing inventories through interactive and textual-based query capabilities.
Other
- UN's UNOSAT United Nations Satellite Centre (UNOSAT) is part of the United Nations Institute for Training and Research (UNITAR)
- UN's Unitar/UNOSAT
- EOS.com since 2015
- EOS.com blog on free sat images
- intro to USGS, EOSDA landviewer, Copernicus Sentinel, Google Earth, Amazon's Earth on AWS, Maxar Open Data, ...
- US - Maxar.com - all kinds of services and use cases
- 285 Maxar-built satellites and 2,750 cumulative years on orbit
- design and manufacture satellites and spacecraft components for communications, Earth observation, exploration and on-orbit servicing and assembly
- maxar.com/open-data emergency/disaster info
- US - Digital Globe - commercial provider
Maps
GIS
Broadcasting
Conditional access
Europe - airspace
