Resurs DK

Resurs-DK1 is a commercial earth observation satellite capable of transmitting high-resolution imagery (up to 0.9 m) to the ground stations as it passes overhead. The spacecraft is operated by NTs OMZ (Russian Research Center for Earth Operative Monitoring).

The satellite is designed for multi-spectral remote sensing of the Earth’s surface aimed at acquiring high-quality visible images in near real-time as well as on-line data delivery via radio link and providing a wide range of consumers with value-added processed data.

pacecraft

The Resurs-DK1 spacecraft was built by the Russian space company TsSKB Progress in Samara, Russia. It is modified version of military reconnaissance satellite Yantar-4KS1 (Terilen) [http://www.astronautix.com/craft/yanr4ks1.htm] . The spacecraft is three-axis stabilized. The design lifetime is no less than 3 years, 5 years is expected. Ground location accuracy is 100 m. Onboard storage is 768 G-bits. Data link speed to the ground station is 300 Mbit/s. Maximum daily productivity is 1 million square km.

"DK" in the name stands for Dmitry Kozlov, chief designer of the first satellite of this class Yantar-2K.

Optical subsystem

*Type: apochromatic telephoto
*Focal length: 4000 mm
*Objective diameter: 500 mm
*Spectral range: 0.5-0.9 µm
*Mass: 310 kg

Made by Vavilov State Optical Institute, Russia. [http://soi.spb.ru/r_1251/directions/dir2/optsystems/aerofoto_sys/page1.htm]

pectral Resolution

*0.58-0.8 µm panchromatic

*0.5-0.6 µm green
*0.6-0.7 µm red
*0.7-0.8 µm visible near IR (near infrared)

It is not possible to represent an image in true color because there is no blue band (0.4 - 0.5 µm). However, it is possible to combine red, green and near IR in such way that the appearance of the displayed image resembles a visible colour photograph, i.e. vegetation in green, water in blue, soil in brown. This is not always possible because two similarly coloured objects can have completely different reactions to near IR light.

Green, red and near IR are typically combined to make a traditional false color composite where the near IR is displayed in red, the red is displayed in green, and the green is displayed in blue. This combination is favoured by scientists because near IR is useful for detection of numerous vegetation types. Vegetation appear as redtones, the brighter the red, the healthier the vegetation. Soils with no or sparse vegetation range from white (sand, salt) to greens or browns depending on moisture and organic matter content. Water appears blue, clear water is dark blue to black while shallow waters or waters with high sediment concentrations are lighter blue. Urban areas will appear blue towards gray. Clouds and snow are white.

Focal Plane Unit

Unit features 4 TDI (Time Delay and Integration) sensor arrays, one panchromatic and three multispectral. Each sensor array is composed of 36 "Kruiz" CCD chips. Effective length of the single array is about 36000 pixels. Arrays are grouped in 3 separated lines:

*near IR
*panchromatic and red
*green

This separation is causing a time delay of the colour images combined from green, red and near IR, so fast moving objects are shown in triplets. Moving object speed and direction can be calculated. All 4 arrays can work simultaneously, so it is possible to combine panchromatic and 3 multispectral images in one pansharpened color composite.

Sistem use 10-bit ADC

Focal Plane Unit is made by NPO Opteks, Russia [http://www.mospravda.ru/issue/2006/12/25/article4205/]

CCD

The CCD "Kruiz" is a 1024 pixel x 128 line, high speed TDI sensor. The active imaging area is organized as 1024 vertical columns and 128 horizontal TDI rows. [http://spiedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG005944000001594409000001&idtype=cvips&gifs=yes]

*Pixel size: 9 x 9 µm
*Number of TDI stages electronically selectable: 128, 64, 32, 16, 8
*Two readout shift registers and two output amplifiers allowing twice faster readout
*Selftest without illumination
*Full well capacity: 120 000 electrons
*Dynamic range: 2500
*Charge transfer efficiency in any direction: more than 0.99998 per transfer
*Maximum quantum efficiency: 0.33 (at 0.72 µm).

Designed jointly by NPO Opteks and ELECTRON-OPTRONIC.
Produced by ELECTRON-OPTRONIC (now is a ELAR [http://www.npp-elar.ru/tdi.html] )/

patial resolution

Panchromatic

At the altitude of 360 km
*Nadir: 0.9 m
*30 degrees tilt: 1.0 m At the altitude of 604 km
*Nadir: 1.5 m
*30 degrees tilt: 1.7 m

Multispectral

1.5-2 m [http://www.geodesign.com.br/Htmls/resurs_dk1.html]

Temporal resolution

The revisit rate is 5 to 7 days off-nadir.

wath

Swath width at the altitude of 350 km:
*4.7 - 28.3 km (at nadir)
*40 km (at ±30°)

Arina

Russian research hardware for detection of high-energetic electrons and protons, their identification, detection of high-energetic particles bursts – earth-quake signs.
*Mass: 9 kg

PAMELA

PAMELA Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics is Italian research hardware, meant for exploration of antiparticles of nuclear and electron-positron composition of primary cosmic rays.
*Mass: 470 kg

Major Current Tasks

*Data supply for resource management and economical activity (inventory of natural resources, topographic and thematic mapping).
*Monitoring of pollution sources of the atmosphere, water and soil with the view of providing Federal and regional environmental authorities with the relevant information to make management decisions.
*On-line monitoring of man-caused and natural emergencies for the purpose of effective planning and timely performing of measures to eliminate damages.
*Supplying home and foreign consumers on a commercial basis.
*Research activities (PAMELA and Arina experiments).

External links

* [http://eng.ntsomz.ru/spacecraft/resurs_dk Official site]
* [http://www.astronautix.com/craft/yanr4ks1.htm Yantar-4KS1]
* [http://sun.ntsomz.ru/data_new/granule/main.php Over 6000 images from Resurs-DK1]
* [http://www.geodesign.com.br/Htmls/resurs_dk1_samples.html 26 high resolution images from Resurs-DK1]
* [http://landsat.gsfc.nasa.gov/education/compositor/ Why do satellite images look so different?]
* [http://www.sovinformsputnik.com/ http://www.sovinformsputnik.com/]