POLAR ORBITER WEATHER SATELLITES This report complied from information supplied by Douglas Deans, Dunblane, Scotland. POLAR APT & DIGITAL STATUS. ========================== Author : Douglas S Deans E-mail : gm4vzy@googlemail.com Twitter : Douglas Deans @GM4VZY There are no updates. SECTION 1: POLAR APT/LRPT REPORT – 2024. ============================================== INFORMATION and UPDATES. None. Satellite Frequency (MHz) Status Image Quality NOAA 15 137.620 (APT) on periods of synch problems. NOAA 18 137.9125 (APT) on good NOAA 19 137.100 (APT) on good Metop-B No LRPT service Metop-C No LRPT service Meteor M N2-2 137.900 (LRPT) off (see Note 7). OQPSK, 72k Meteor M N2-3 137.900 (LRPT) on Poor (see Note 8). OQPSK, 72k (at time of sending !) NOTES. 1. NOAA 14 was decommissioned on 23rd May 2007. 2. NOAA 12 was decommissioned on 10th August 2007. 3. NOAA 17 was decommissioned on 10th April 2013. 4. NOAA 16 was decommissioned on 9th June 2014. 5. Metop-A end of life switch off 15th November 2021. 6. Elements are available from :- http://www.space-track.org and http://celestrak.com/NORAD/elements/ 7. Meteor M N2-2 has likely been hit by a micro-meteorite. It has changed orbit and been de-pressurised. Although under control again the thermal balance is an issue and main problems are overheating of the batteries which keep switching to backup. LRPT transmitter cannot operate under those arrangements and is off permanently. LAUNCHES. Meteor M N2-3 launch possibly late June/early July. This satellite was built and stored about 7 years ago ! SECTION 2: POLAR HRPT/AHRPT REPORT – 2024. ================================================ INFORMATION and UPDATES. None. Satellite Frequency Antenna Mode Image Quality (MHz) NOAA 15 1702.5 Omni HRPT Weak(periods of problems) NOAA 18 1707.0 RHCP HRPT Good NOAA 19 1698.0 RHCP HRPT Good Feng Yun 3A 1704.5 RHCP see note 6. Feng Yun 3B 1704.5 RHCP off. see note 6. Feng Yun 3C 1701.4 RHCP see note 9. Off. Feng Yun 3D 7820 see note 11. Feng Yun 3E 7860 commissioning see note 11. Metop-B 1701.3 RHCP AHRPT Good. Metop-C 1701.3 RHCP AHRPT Meteor M N2-2 1700.0 see note 7 and 10 on. NPP see Note 8. NOAA 20 see Note 8.1 NOAA 21 see Note 8.1 Arktika-M1 see Note 12 NOTES. 1. NOAA 14 was decommissioned on 23rd June 2007. 2. NOAA 12 was decommissioned on 10th August 2007. 3. NOAA 17 was decommissioned on 10th April 2013. 4. NOAA 16 was decommissioned on 9th June 2014. 5. Metop-A end of life switch off 15th November 2021. 6. I am also grateful to Dave Wright of Dartcom for confirming that unfortunately (as usual) the Chinese have not strictly complied with the CGMS AHRPT Global Standard so reception using a standard Metop AHRPT receiver is not possible. Update: The second in the series, Feng Yun 3B was launched on 4th November 2010. I expect the information above for 3A will equally apply to 3B. My thanks to Johnny Lin for drawing this to my attention. 7. Meteor M N2-2 is neither using full HRPT or AHRPT and cannot be received using standard receivers. Please see other mails for further explanation :- https://groups.io/g/weather-satellite-reports/message/2096 8. Meteor M N2-3 LRPT is showing weakness of signal to the south of receiving station on descending pass and weakness of signal to the north on ascending pass. Possible issue with LRPT antenna. 8.1. As those weather satellites have no S-band transmitter, they are included for information only. 9. I am grateful to David Wright of Dartcom (http://www.dartcom.co.uk) for providing up to date information for Feng Yun 3C. Now fully operational but the Chinese have changed the data rate compared to FY-3A and FY-3C DB downlink data rate is 3.9 Mbps after RS Encoding. Frequency is also different - it is on 1701.3 MHz same frequency as Metop A/B. It still requires a special AHRPT receiver like FY-3A/B. They have also changed the polarisation of the X-band downlink to LHCP. 10. Meteor M N2-2 has likely been hit by a micro-meteorite. It has changed orbit and been de-pressurised. Although under control again the thermal balance is an issue and main problems are overheating of the batteries which keep switching to backup. AHRPT is on when spacecraft (solar panels) are illuminated. 11. Although AHRPT is not available on FY-3D/3E on the 1700 MHz band as with previous satellites of the series it is available on 7820/60 MHz. There are amateurs with working systems on those frequencies so I have added the satellite for information. 12 Arktika-M1 is in a specialised Molnyia orbit. For more information please see :- https://cosmoquest.org/x/2021/03/roscosmos-launches-artktika-m-1-to- monitor-arctic-regions/