March 23, 2017

Event Archive

03/27/2015: End of commercial exploitation of Spot 5 satellite

Spot 5's commercial mission came to an end on 27 March 2015, bringing the great adventure begun in 1986 with Spot 1 to a close after nearly 13 years of loyal service.

But not quite to a close, in fact, as following the success of the Take 5 experiment on Spot 4, it waqs decided to renew the experiment, co-funded by ESA, on Spot 5.

The objective of this end-of-life experiment, like the previous one, is to prepare for the arrival of ESA's Sentinel-2 satellites. Spot 5 will be switched to a high-revisit orbit (5 days) to acquire imagery of about 150 predefined sites every 5 days for 5 months, meaning 30 acquisitions of each site, to monitor the growth of vegetation and summer crops.

On 2 April Spot 5 was lowered 2.5 km to a new 820-km orbit with a 5-day revisit period.

After a period of intense preparation, Take 5 images will be tasked the mission engineers at the Spot Operations Control Centre (CMP) for the complete duration of the experiment (until the start of September). The first images are expected on 8 April.

A short animation explaining the Take 5 experiment:


Take 5: the experiment to prepare the mission... by Cesbio


01/11/2013: Spot 4 satellite officially retired from service

Spot 4 is dead, long live Take 5! A true king of optical satellite imagery took its final bow on 11 January when Spot 4 was retired from commercial service.

This decision came after 15 years of loyal service, during which the satellite acquired some 10 million archived scenes and was inoperative for less than 0.3% of its time in orbit (0.7% including downtime due directly to the extension of its initial service life).

Above all, it was the penultimate satellite in a series offering unrivalled ground coverage and resolution, reaching its peak with Spot 5 (2.5-m colour imagery covering an area of 60 km x 60 km) and its successors Pleiades.

The Spot series has achieved world renown through Spot Image, the company formed to market its imagery, and through the International Charter on Space and Major Disasters, for which Spot is the most used among the international fleet of satellites that can be called on to acquire imagery of disaster areas (Spot is called on for 3 Charter activations out of 4 on average).

Spot 4 is bowing out with class, as it is going to be used to lay the groundwork for the future. From the end of January, it has been assigned a new mission: Take 5.

For this new mission, Spot 4 will be lowered 2.5 km to put it in a 5-day high-revisit orbit to prepare algorithms, methods and applications for the future optical component of the GMES programme, Sentinel-2.

Spot 4 will thus combine a revisit rate equivalent to that of Sentinel-2 with a wide imaging swath (120 km in dual-instrument mode), resolution of the same order of magnitude and four spectral bands.

Many scientific users in France—80 research laboratories and organizations including CESBIO, INRA, CEA, CIRAD, Ifremer, IRSTEA, Meteo France, CETE and DREAL—have expressed their eagerness to be able to employ such data. The mission also offers good prospects for international collaboration through its partners NASA, ESA, JRC and CCRS.

The satellite will systematically acquire imagery of 42 sites, 16 in France, over a period of four months.

Level 1A products will be generated by Spot Image, while higher-level products will be generated by the MUSCATE production centre at CNES and disseminated to a broad community of users during the course of 2013 through the PTSC land surfaces portal.

This operation, which is exceptional in terms of its duration, resources and the added value it brings to a system at the end of its operational life, will be keeping Spot 4 busy before the start of de-orbiting operations planned in June.

The Take Five team at CNES and Spot Image is fired up by the idea of getting a little more mileage out of the venerable Spot 4 satellite before it takes its final curtain call, and telling it to "take five"!


03/15/2011: Earthquakes and Tsunami in Japan - Spot 5 supplies maps to relief services

Carte du 14/03/2011 couvrant la zone entre Fukushima et Ishinomaki Updated 15 March 2011 :

The SERTIT regional image processing and remote sensing department continued mapping damage on the northern tip of Japan using Spot imagery acquired on Sunday 13 March. The maps were sent to Mathieu Grialou, CNES’s representative at the French Embassy in Japan. SERTIT recorded 900 zones that had been completed flattened along the 400 kilometres of coastline imaged by Spot 5.

Once the French civil protection agency DSC has confirmed exactly where French relief teams are expected to be dispatched, SERTIT will also generate maps from very-high-resolution imagery acquired by US satellites where possible.

Four maps of disaster zones generated yesterday by SERTIT:

Map produced on 14/03/2011 covering la zone de Minamisanriku
Map produced on 14/03/2011 covering
Minamisanriku area
Map produced on 14/03/2011 covering Ofunato area
Map produced on 14/03/2011 covering
Ofunato area
Map produced on 14/03/2011 covering Minamisanriku to Yamada sector
Map produced on 14/03/2011 covering
Minamisanriku to Yamada sector
Map produced on 14/03/2011 covering Miyaku to Hashikami sector
Map produced on 14/03/2011 covering
Miyaku to Hashikami sector

See maps of the disaster on the SERTIT website (in French and English)

Friday 11 March at 14:46 local time (6:46 CET), the ground shook for two minutes that seemed like an eternity all along the East coast of Japan’s Honshu Island. The quake registered 8.9 on the Richter scale, the strongest for 30 years in a country accustomed to large earthquakes.

The quake with its epicentre less than 125 km from Japan’s shores triggered a tsunami that left a trail of destruction along the coasts of the prefectures of Fukushima, Iwate and Miyagi, reaching the city of Sendai and its 1 million inhabitants less than half an hour later. Ten-metre-high waves crashed into the coastline, bringing down buildings, sweeping cars and boats several kilometres inland, shutting down nuclear power plants and posing the threat of a major nuclear accident at the Fukushima power station.

Less than one hour after the first tremors were felt, the International Charter on Space and Major Disasters was activated by the Japanese space agency JAXA on behalf of Japan’s Cabinet Office (at 7:35 CET).

Anticipating receipt of the official activation request, CNES asked Astrium Geo Information Service (Spot Image) to urgently task SPOT 5 to acquire imagery of the disaster zone, coordinating its efforts with the Project Leader appointed by JAXA at 10:55.

Despite unfavourable cloud cover forecasts, CNES decided to task two series of SPOT 5 acquisitions to meet the Project Leader’s request for imagery of more than 400 km of coastline. The first tasking plan, optimized to include the prefecture of Fukushima (where several nuclear power stations and dams were located), was complemented by another covering the Kamaishi region with its numerous coastal towns and another nuclear power station.

Planning ahead for the weekend, CNES and Spot Image decided to call up their teams for Saturday to generate imagery acquired in the morning and post them on a website for all Charter stakeholders.

CNES also offered the JAXA Project Leader its support in generating damage maps. This proposal was accepted and CNES asked SERTIT to produce rapid maps ready for use by civil protection teams. A series of seven maps was generated in less than six hours from images acquired on the Saturday and made available to the Japanese authorities on Sunday morning. They showed a trail of devastation along the entire coastline up to 3.5 km inland on average and as far as 5 km in places.

In all, SERTIT detected 441 urban districts or areas that had been severely damaged or destroyed along 200 km of coastline.

SERTIT’s maps were also sent to French civil protection teams in order to plan the relief effort of the French contingent flown out to Japan on Sunday 13 March. SERTIT is continuing to compile maps from imagery acquired to the north and south of the areas already imaged and is eagerly awaiting new SPOT acquisitions from 13 March. This imagery is currently in production at Spot Image and SERTIT expects to have compiled new damage maps by late afternoon.

The seven maps used to assess the impact of the tsunami on the North-East coast of Honshu are the first of their kind covering an area of more than 100 km. In particular, teams were able to use a series of SPOT 5 natural colour images covering 100 km of coastline around the city of Sendai.

Maps generated from higher-resolution satellites with narrower coverage (RapidEye, GeoEye, QuickBird, etc.) provide more detail but are less strategically important when planning relief efforts in the first days following a major disaster of this kind. This confirms the value of SPOT 5’s coverage and resolution in the event of large-scale disasters like a tsunami, complementing high-resolution sensors used to map damage to buildings over much smaller areas.

Article by Catherine Proy and André Husson, CNES’s representatives for the 'International Charter on Space and Major Disasters.'


Spot Data Conversion into Reflectances

Document for converting Spot product numerical levels into Top Of the Atmosphere (TOA) reflectances.

This document contains conversion formulae as well as the different coefficients to use for all Spot satellites: calibration, gain change coefficients, solar irradiance integrated in the spectral bands, etc.

SPOT ABSOLUTE CALIBRATION:
SYNTHESIS


Preferential access to Spot Products

  • for French laboratories through the ISIS programme funded by CNES