| Satellite Characteristics | Parameter Value(s) | Notes |
|---|---|---|
| General: | ||
| Satellite Manufacturer | Alcatel Space Industries | |
| Launch Date | 12/04/99 | |
| Launch | Proton | |
| Projected Lifetime | >12 years | |
| Orbital Position | 36º E ± 0.1 º | |
| Frequency Plan: | ||
| Operational Transponders | 12 | 31 channels, including all payloads. |
| Total Transponders | 12 | The W4 satellite has a total of 31 transponders. Nineteen channels are used by the Russian payload, which is independent of the African payload. The Russian payload is described in a Satellite Data Sheet below. |
| Frequency Accuracy | ±1 x 10 -6 | At satellite delivery. |
| Frequency Stability |
±5 x 10 -7 ±1 x 10 -6 ±5 x 10 -6 |
Over any 24 hour period. Over any month. Over the min. operational lifetime. |
| Coverages: | ||
| Nominal Transponder Power | 57 W Wide Beam and Steerable Spot Beam | Both coverages. |
| Polarisation | Single Linear | All coverages. |
| Polarisation Discrimination | 30 dB | All coverages, receive and transmit. The exact value is dependent upon the location within the coverage zone. |
| Transponder Gain: | ||
| Fixed Gain Mode: | Precise operational gain adjustments are made according to the traffic configuration of the transponder. | |
| Gain Adjustment Range | 15 dB | |
| Gain Step Size | 1 dB | |
| IPFD for Saturation | -(92 + X) to -(77 + X) | In dBWm-2. The value X is the G/T in dBK -1 in the direction of the location considered. |
| IBO Adjustment Range | 0 - 10 dB | For a reduced Input Power Flux Density (IPFD) range of -(84 + X) to -(92 + X) dBWm -2 . |
| IBO Adjustment Step Size | 1 dB | |
| Automatic Level Control Mode: | ||
| Dynamic Range | 15 dB | |
| IPFD for Saturation | -(92 + X) to -(77 + X) | In dBWm-2. The value X is the G/T in dBK -1 in the direction of the location considered. |
| IBO Adjustment Range | 0 -7 dB | |
| IBO Adjustment Step Size | 1 dB | |
| Beacon: | ||
| Number | 1 | Telemetry and ranging carrier. |
| Beacon Frequency | 11 706.850 MHz |
Nominally active beacon frequency. Selectable by ground command. |
| Frequency Stability | < ±50 kHz | With respect to the nominal frequency. |
| Minimum EIRP | 9 dBW | Anywhere within the African coverage and within any geographical area served by the Steerable Spot Beam. |
| Polarisation | Horizontal | |
| Satellite Characteristics | Parameter Value(s) | Notes |
|---|---|---|
| General: | ||
| Satellite Manufacturer | Alcatel Space Industries | |
| Launch Date | 12/04/99 | |
| Launch | Proton | |
| Projected Lifetime | >12 years | |
| Orbital Position | 36º E ± 0.1 º | |
| Frequency Plan: | ||
| Operational Transponders | 19 | 31 channels, including all payloads. |
| Total Transponders | 19 | The W4 satellite has a total of 31 transponders. Twelve channels are used by the African payload load, which is independent of the Russian payload. |
| Frequency Accuracy | ±1 x 10 -6 | At satellite delivery. |
| Frequency Stability |
±5 x 10 -7 ±1 x 10 -6 ±5 x 10 -6 |
Over any 24 hour period. Over any month. Over the min. operational lifetime. |
| Coverages: | ||
| Nominal Transponder Power | 85 W | |
| Polarisation | Dual Circular | |
| Polarisation Discrimination | 27 dB | Receive and transmit. The exact value is dependent upon the location within the coverage zone. |
| Transponder Gain: | ||
| Fixed Gain Mode: | Precise operational gain adjustments are made according to the traffic configuration of the transponder. | |
| Gain Adjustment Range | 15 dB | |
| Gain Step Size | 1 dB | |
| IPFD for Saturation | -(92 + X) to -(77 + X) | In dBWm-2. The value X is the G/T in dBK -1 in the direction of the location considered. |
| IBO Adjustment Range | 0 - 10 dB | For a reduced Input Power Flux Density (IPFD) range of -(84 + X) to -(92 + X) dBWm -2 . |
| IBO Adjustment Step Size | 1 dB | |
| Automatic Level Control Mode: | ||
| Dynamic Range | 15 dB | |
| IPFD for Saturation | -(92 + X) to -(77 + X) | In dBWm-2. The value X is the G/T in dBK -1 in the direction of the location considered. |
| IBO Adjustment Range | 0 -7 dB | |
| IBO Adjustment Step Size | 1 dB | |
| Beacon: | ||
| Number | 1 | Telemetry and ranging carrier. |
| Beacon Frequency | 11 706.850 MHz |
Nominally active beacon frequency. Selectable by ground command. |
| Frequency Stability | < ±50 kHz | With respect to the nominal frequency. |
| Minimum EIRP | 9 dBW | Anywhere within the African coverage and within any geographical area served by the Steerable Spot Beam. |
| Polarisation | Horizontal | |