Meteor-3 is a USSR/Russian Federation LEO weather/environmental satellite series of ROSHYDROMET as sponsoring agency. The program development started in the early 1980s with a first launch in Oct. 1985. A total of seven spacecraft were built for the Meteor-3 series by VNIIEM (All- Russian Scientific and Research Institute of Electromechanics) of Moscow. In the timeframe of the 1980s, the USSR plans envisaged the development of an integrated hydrometeorological satellite system for the 90s, comprising geostationary (GEO) and LEO (Low Earth Orbit) satellites.
The overall objectives of the Meteor-3 program were:
· To obtain, on a regular basis, global data on the distribution of cloud, snow, and ice cover and surface radiation temperatures once or twice daily at times close to the synoptic times
· To obtain regional data on the distribution of cloud, snow, and ice cover on a regular basis
· To obtain, during each communication session, global data on the vertical temperature and humidity distributions in the atmosphere
· To observe, on a regular basis, information on radiation conditions in near-Earth space globally once or twice a day, and for each orbit in storm conditions.
Figure 1: View of the Meteor-3 spacecraft (image credit: CIRA, Colorado State University)
The spacecraft series incorporated three-axis stabilization with a pointing accuracy of about 0.5º. The S/C platform was essentially a cylinder of 1.1 m in diameter. Twin span solar panels, each of size 3.7 m x 1.5 m, provided an average power of about 500 W. The spacecraft mass was in the range 2150-2250 kg with a sensor complement of 500-700 kg. Nominal lifetime = 2 years. The orbit was maintained by a cold gas thruster system.
RF communications: Downlink transmission in UHF (466.5 MHz) and in VHF (137.8 MHz) frequency bands. Meteorological data was transmitted to four primary sites in Moscow, Novosibirsk, Chabarowsk, and Tashkent (spacecraft operator/coordinator: NPO Planeta). ground workstations. There were also 80 APT (Automatic Picture Transmission, compatible with NOAA APT) stations in Russia/CIS receiving Meteor data (on 137-138 MHz). The APT stations provided data reception for the Meteor and for the NOAA series satellites.
Both Meteor-2 and Meteor-3 satellite types provide main and regional centers of Russia and CIS (Commonwealth of Independent States - part of former Soviet Union or USSR) with global data on the distribution of clouds, snow and ice in VIS and IR bands, radiation flux data at least twice daily, atmospheric temperature-humidity sounding data, data on the temperature of the ground surface, cloud-top heights and sea surface temperature.
Orbit: Non-sun-synchronous near-circular and near-polar prograde orbit, drifting slowly with local time (212 day period); mean altitude = 1230 km; inclination = 82.5º; period = 109 minutes. The higher altitude selection of the Meteor-3 series (about 200 km compared to the Meteor-2 series) enables an extension of the instrument swath width, thereby providing complete coverage of the Earth's surface.
The first Meteor-3 launch took place on Oct. 24, 1985 from the Plesetsk Cosmodrome using the F2 launch vehicle.
Figure 2: Illustration of the Meteor-3 spacecraft (image credit: VNIIEM)
1) Television Systems
TV camera systems MR-2000M and MR-900B. Objective: Observation of daytime Earth cloud cover in the visible spectrum (0.5 - 0.7 µm) at a local solar angle not less than 5º. Spatial resolution of 0.7-1.4 km for MR-2000M and 1-2 km for MR-900B. The swath width = 3100 km (MR-2000) and 2600 km (MR-900). The MR-2000M camera provides storage and direct transmission operation. The MR-900B camera has no storage operation mode (only direct transmission). The data acquisition range is stable within a radius of 3000 km. Output products: individual images, photomosaics of images from 2-3 passes over receiving station within 300 km in radius. Global photomosaics of images of various regions of the globe (twice daily), cloud-free photomosaics of arctic and antarctic oceans once in five days.
Table 1: TV system parameters
2) Optical Scanning Systems
Klimat (Infrared Radiometer), operational since 1988. Klimat was an electromechanical device with a scan angle of ± 48º, a swath width of 1300 km, a spatial resolution of 0.45 km x 0.9 km; IFOV=0.7 x 1.4 mrad; surface temperature range = 223-313 K; temperature difference at 300 K, background = 0.2 K. Measurement spectrum: 10.5 to 12.5 µm. Instrument mass = 75 kg. Detectors: CdHgTe cooled to 80 K. Output products: Global photomosaics of Northern and Southern Hemispheres, tropical zone, individual images; digital SST and top-of-cloud height charts, tropical cyclone coordinates, cloud amount data on regular grid over the globe. 1)
SM (Multichannel Spectrometer), also known as "Device 174-K" (optical instrument for atmospheric observation). Electromechanical device, scan angle = ± 24º. Scanning 10-channel IR radiometer for atmospheric thermal sounding. Spectral range: 9.65 - 18.7 µm (9.65, 10.60, 11.10, 13.33, 13.70, 14.25, 14.43, 14.75, 15.015, 18.70). Resolution = 42 km; swath width = 1000 km; output products: SATEM messages with atmospheric thermal sounding data (total ozone content)
3) Radiation Measurement System
RMK-2 (Radiation Measurement Complex). Objectives: Registration of flux densities of protons in the 5-90 MeV and electrons in the 0.15-3.0 MeV energy regions.
- Electron and proton flux density. Ranges: 2.5 -1 x 105 particles/cm2 s, and 0.111 - 4.4 x 103 particles/cm2 s
- Radiation dose exposition in the range: 1 x 10-7 - 5 x 10-4 particles/s
- Number of channels: 12
4) Sensors/systems from other agencies
A new feature of the Meteor program is the incorporation of sensors and instruments from other space agencies through international cooperation. The following foreign sensors/payloads are flown on Russian missions:
TOMS (Total Ozone Mapping Spectrometer), a NASA sensor. A Meteor-3 series S/C (Meteor-3-6) was successfully launched on August 15, 1991 with a NASA sensor onboard. A refurbished TOMS sensor (of the original engineering model for Nimbus-7) was part of this payload. The instrument transmited its data to ground stations in the US and in Russia on a daily basis (US archive at GSFC, Russian archive in Dolgoprudny outside of Moscow). The orbital lifetime was projected at two years. Objective: Mapping of vertical ozone profiles. TOMS has a swath width of 3100 km. Six spectral bands at: 0.3125, 0.3175, 0.3313, 0.3398, 0.360, and 0.380 µm. The ground resolution is 47 x 47 km at nadir and 62 x 62 km overall. Note: The TOMS instrument failed to provide operational service after December 27, 1994. See also TOMS Missions for a detailed description. 2) 3) 4)
ScaRaB (Scanner for Radiation Budget), of CNES [France (CNES, LMD), Russia (Planeta, RKA), Germany (GKSS) are program partners]. ScaRaB is a joint development of a cross-track scanning radiometer. Its objective is the collection of data on shortwave and longwave radiation (reflected solar and emitted thermal radiation) to estimate the Earth's radiation budget at the top of the atmosphere on global and regional scales. The instrument features four channels. Channels 2 and 3 are considered the main channels, while channels 1 and 4 are auxiliary channels. The optical subsystem features four parallel telescopes, one telescope per channel, they are identical except for their filters. 5) 6) 7)
ScaRaB uses BARNES pyroelectric detectors for all bands (placed at the focus of a spherical aluminium mirror), which are sensitive only to the AC component of the signal (i.e. the modulated energy). Hence, chopping is needed for each pixel. This reduces the influence of the self radiation of the telescope and filters. Two mechanical choppers are used (one for two channels), providing a 10 Hz chopping frequency. The four channels, the two choppers, and a filter wheel dedicated to channel 2 and 3, are mounted on a scanning optical bench (rotor). The telescopes are swiveled by the optical bench so that no extra mirror for the scanning is needed. This reduces the likelihood of offsets dependent on the scanning angle.
Table 2: Spectral bands of ScaRaB
The spatial resolution of ScaRaB data is 48 x 48 mrad, scan angle=100º, swath width = 3200 km. ScaRaB points to nadir and scans the full field of view (FOV) within six seconds. In this cross-track mode data are generated continuously.
Table 3: ScaRaB instrument parameters
Calibration subsystem: Gray lamps and blackbodies are used for on-board gain calibration; deep space is used for offset calibration. That subsystem comprises a set of two reference blackbodies for channels 3 and 4, and a set of gray calibration lamps for channels 1, 2 and 3. There is continuous thermal control of the blackbodies. The gray lamps are turned on during the calibration session (typically once per day). In addition, there are short wave references, consisting of two lamps for the calibration of channels 2 and 3 (typical use is once per month). On the ScaRaB/Meteor-3-7 mission, however, the lamp system was damaged so that actual calibration was performed by using the instrument temperature and a pre-launch established gain-temperature law. The remaining lamps were then used to verify this calibration. During one year of operation, no significant sensor degradation was observed.
ScaRaB has a duty cycle of 100%, data rate=3 kbit/s, data volume=18 Mbit/orbit. An instrument mass memory provides data storage for up to 12 hours. The mass of the instrument is 40 kg, the maximum power use is 70 W.
The data processing system is based on algorithms for transforming the instantaneous measurements of radiances, filtered by the optics and detectors, into estimates of the monthly mean values of the radiant excitations in the solar and thermal domains, at the top of the atmosphere. This requires corrections for non-flat spectral response, anisotropic, and diurnal variations. The estimates are provided on a spatial grid of 250 km.
Table 4: Meteor-3 series satellite/observation characteristics
PRARE (German Microwave Tracking System). PRARE is flown on Meteor-3-7 as a passenger instrument. The PRARE (Precise Range And Range-Rate Equipment) system is being described under the ERS-2 mission.
Note: Meteor 2-22 was launched in honor of A. G. Iosiphyan, the founder and first director of VNIIEM and the designer of the Meteor-1, Meteor-2, and Meteor-Priroda satellite series.
1) Y. V. Trifonov, "Meteor-3 space system for hydrometeorological observation," VNIIEM, Moscow, 1991
2) `Soviets to Launch U.S. Ozone Mapper,' Space News Aug. 5-18, 1991, p. 14
3) `TOMS Arrives Successfully in Space,' Space News Aug. 19-25, 1991, p. 2
4) "TOMS Mission Declared Over by NASA Officials," Space News, February 20-26, 1995, p. 11
6) J. L. Monge, R. Kandel, L. A. Pakhomov, B. Bauche, "ScaRaB Earth radiation budget scanning radiometer," SPIE, Vol. 1490 , `Future European and Japanese Remote Sensing Programs,' 1991
7) J. Mueller, et al., "Ground Characterization of the Scanner for Radiation Budget (ScaRaB) Flight Model 1," Journal of Atmospheric and Oceanic Technology, Vol. 14, No 4, pp.802-813, 1997.
8) Courtesy of B. S. Zhukov (IKI RAN), Y. V. Trifonov, and Y. V. Dubrovinsky (VNIIEM), Moscow
This description was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" - comments and corrections to this article are welcomed by the author.