Two New Earth Observation Satellites Launched

Artist's rendition of a satellite - paulfleet/123RF Stock Photo

Artist’s rendition of a satellite – paulfleet/123RF Stock Photo

Two new Earth observation satellites were launched last week from European Space Centre in Kourou in French Guyana, although you may only get to see the data from one. Venµs and OPTSAT-3000 were put into sun synchronous orbits by Arianespace via its Vega launch vehicle on the 1st August. Both satellites were built by Israel’s state-owned Israel Aerospace Industries and carry instruments from Israel’s Elbit Systems.

Venµs, or to give its full title of Vegetation and Environment monitoring on a New MicroSatellite, is a joint scientific collaboration between the Israeli Space Agency (ISA) and France’s CNES space agency.

Venµs is focussed on environmental monitoring including climate, soil and topography. Its aim is to help improve the techniques and accuracy of global models, with a particular emphasis on understanding how environmental and human factors influence plant health. The satellite is equipped with the VENµS Superspectral Camera (VSSC) that uses 12 narrow spectral bands in the Visible Near Infrared (VNIR) spectrum – ranging from 420nm wavelength up to 910 nm wavelength – to capture 12 simultaneous overlapping high resolution images which are then combined into a single image. The camera uses a pushbroom collection technique and has a spatial resolution of 5.3m and a swath size of 27.56 km.

Venµs won’t have full global coverage; instead there are 110 areas of interest around the world that includes forests, croplands and nature reserves. With a two day revisit time, during which time it completes 29 orbits of the planet. This means every thirtieth image will be collected over the same place, at the same time and with the same angle. This will provide high resolution imagery more frequently than is currently available from existing EO satellites. The consistency of the place, time and angle will help researchers better assess fine-scale changes on the land to improve our understanding of the:

  • State of the soil,
  • vegetation growth,
  • detection of spreading disease or contamination,
  • snow cover and glacial movements; and
  • sediment movement in coastal estuaries

A specific software algorithm has been developed for the mission to work with the different wavelengths to remove clouds and aerosols from the satellite’s imagery, giving clear images of the planet irrespective of atmospheric conditions.

The second satellite launched was the OPTSAT-3000 which is an Italian controlled optical surveillance satellite, which will operate in conjunction with the COSMO-SkyMed radar satellites giving Italy’s Ministry of Defence independent autonomous national Earth observation capability across optical and radar imagery.

This is a military satellite and so some of the details are difficult to verify. As mentioned earlier the instrument was made by Elbit systems, and the camera used usually offers a spatial resolution of around 0.5 m. However, it has been reported that the resolution will be much closer to 0.3m because the satellite is in a very low earth orbit of a 450 km.

OPTSAT-3000 will collect high resolution imaging of the Earth, it’s not clear at this stage whether any of the imagery will be made available for commercial/scientific use or purchase, although it is worth noting that COSMOS-SkyMed images are sold.

Two more Earth observation satellites launched shows that our industry keeps on moving forward! We’re really interested, and in OPTSAT’s case hopeful, to see the imagery they produce.

Smashing the Earth Observation Data Silos

Artist's rendition of a satellite - paulfleet/123RF Stock

Artist’s rendition of a satellite – paulfleet/123RF Stock

Earth observation (EO) is an all-encompassing term for monitoring our world, however as soon as you start examining the topography of the field in detail you’ll find all sorts of mountains, valleys and oceans. An illustration of the different stands can be seen if you consider the subject areas such as hydrography, geology, surveying and remote sensing, or think about areas of interest like the land and the marine specialists, and finally think about sensors specialists for LIDAR, optical or hyperspectral imaging. Historically a lot of these groupings have tended to work in relative isolation with a limited amount of interaction between them, which has created a lot of EO data, and knowledge, silos. However as satellite technology has developed, the quantity of EO data available has increased exponentially; for example, Landsat is currently collecting fourteen times as many images each day than it was in the 1980’s. Whilst many datasets have been collected, few have been brought together. This is due to both computing power required to manage large datasets and the difficulties of cross-calibrating sensors with different errors and uncertainties. Cloud computing has broken through most of the data processing obstacles, giving the potential for many more people to get involved in data manipulation, modelling and visualisation. The next challenge is to smash open these data silos, and provide access to historical archives, and new collections, to both the scientific community, and anyone else who is interested. Joining together the different strands of data and knowledge will promote innovation and help us significantly develop our understanding of the planet. Individual space agencies are working on this through making new data freely available and by analysing their own historical archives and then reprocessing them to improve consistency. Some examples include:

Progress is being made, but there are still limitations as often this only represents the bringing together of data from a single mission; a product set or thematic group. There is a need to be bolder and to amalgamate much wider datasets. Last week, Taiwan demonstrated how this could be achieved by presenting their petascale database for assessing climatic conditions, which has brought together data from the atmosphere, hydrology, ocean currents, tectonics and space. The Earth Science Observation Knowledge base holds ten and half million records and gives scientists near real time access to data. EO has a vast array of valuable data and is collecting more every day. We’re starting to smash the data silos, but we need to do more to achieve the next step change in understanding how our world works.