What is new at Dundee Satellite Station Ltd

Dundee Satellite Station Ltd home page
Here we occasionally write about things that are happening that we hope folks will find of interest!

Hottest Day since Dec 2020 (04 Jun 2021)

Our weather station recorded 18.9°C, marginally beating the best since we put up the weather station in Dec 2020 which was 18.8°C on 18 March 2021.
The coldest remains -14.8°C on 11 Feb 2021.

Clearing Storm Drains (31 May 2021)

When we were selecting the new site for DSS Ltd one aspect we checked was the flood risk using the maps provided by SEPA Unsurprisingly, the former RAF Errol site was not at risk as no doubt they performed due diligence during WW2 as well in selecting the location. However, one can never assume that the climate is static and for operational reasons the base had good sized storm drains along both sides of the runways. As part of the preparation of the new high-tech space-age site site we had to get our hands dirty doing the first maintenance for 7 decades the old fashioned way with a spade and wheelbarrow to dump the accumulated mud and vegetation.
Photo of work to clear the WW2 storm drains, shows man waist deep in one

Gearbox Work (20 May 2021)

As part of the renovation of the remaining antennas we have stripped two of them down to clean and service them, replace flexing cables, etc. One aspect we wanted to do was servicing of the gearboxes as they have been sealed up for many years. Unfortunately for us, the company that used to supply the antenna drive trains was bought over in 2018 and gutted of the useful support they provided to us. The only option we seemed to have was to get the UK importer to ship them off for the work, adding to the overall time, cost and unnecessary risk. The antennas use a cycloidal final drive and the manufacturer advises against opening them and do not provide instructions to do this.

But how hard could it be?

We decided to have a go with one gearbox that was known to be worn and in need of replacement, so we dismantled it after buying some large bearing pullers. Here is the internal parts in their second bath of paraffin during the cleaning process:
Photo of gearbox internals being cleaned in a bath of paraffin

Thankfully we worked out the trick to getting it all back together again with the three eccentrically driven disks in the right phase relationship. So next we will tackle the good gearboxes!

Installation of Steelworks (12 Apr 2021)

The installation of the steel support structure for the new antenna plinths by one of our local companies, Jackson Steel Structures Ltd of Dundee, was completed in April. These supports have mounting holes for all 3 types of antenna we had built for Dundee and allows us to swap them around as necessary.
Photo of the installation team working on the steel structure for #1 antenna plinth

Antenna Plinths poured (24 Mar 2021)

We had the concrete plinths for antennas #1 and #4 poured with the help of local builders and the concrete supplier also on the former RAF Errol airfield. We decided to make the #1 plinth larger so we can accommodate antennas up to 5m in the future and still survive 120mph wind speeds, without needing any modifications of the foundations.

The image below shows this larger #1 plinth being poured along with the 3.7m antenna (#2) that is already in operation. It is planned these next two antennas will primary be for remote sensing / environmental monitoring.
Photo of the concrete truck pouring into the shuttering for #1 antenna plinth

Remote Sensing Images (30 Jan 2021) and Weather (08 Feb 2021)

We are now producing some latest images files from the weather satellites that are updated automatically. For now this free and open service is only providing the UK "overhead" images from the NOAA and METOP series of satellites carrying the AVHRR instrument, but we hope to extend the coverage and range of image data soon.

The site also has a local weather station that normally updates every half hour. User Ctrl+R to refresh if needed.

NOTE: The weather station equipment is not mounted according to the official requirements for wind measurement height (10m / 33 feet), or distance from tarmac for temperature, so we cannot guarantee the accuracy.

First Overhead Pass of 2021 (01 Jan 2021)

This infra-red images was taken by NOAA-19 on a south-bound pass, overhead at 07:51 on Friday 1st Jan 2021, which we re-projected to this 1024 x 1024 sized image (with the 5 degree grid lines and coast automatically overlaid). You can also get a 4k x 4k version which is 12MB and shows the resolution limit of the AVHRR scanner. However, it is still impressive for an instrument whose first design was flown in 1978 on the TIROS-N satellite!

Image from the NOAA-19 satellite showing the UK on New Year's Day

Terra 21st Birthday (18 Dec 2020)

The satellite Terra was launched on the 18th Dec 1999 and today has its 21st birthday, an unusually long time for any satellite to remain in operation. While the MODIS sensor is showing some signs of degradation and it has been largely replaced by the newer NPP and NOAA-20 birds, it is still worthy of note. This quick look-image was taken around 12:03 today and shows the weather features bearing down on the UK.

Image from the Terra satellite on its 21st birthday showing the UK

Errol Antennas (03 Dec 2020)

We have got to the stage of having two tracking antennas in routine operation. Here you can see those two antennas tracking, along with those still to be refurbished and put back in to service.

Image of the first two operational antennas at the RAF Errol site

First Pass from Errol (15 Sep 2020)

We were able to receiver our first images at the new RAF Errol site using our 3.7m antenna with the X-band feed formally used in Dundee. While we still have a long way to go to be fully operational, it is good to finally see something in return for our efforts and all of the support we have been getting.

The current 3.7m pedestal dates from 1997 (though the reflector is from 1975) and was constructed to allow DSRS to take data from the NASA EOS satellites Terra and Aqua which were eventually launched on December 18, 1999 and May 4, 2002 respectively. Both have far exceeded their planned 6 year mission life, though the sensor data is poorer now than when new.

The image was taken by the satellite Terra on a south-bound pass, starting at 11:44:19 and ending 11:58:37 UTC. What is shown below is a quick-look generated at a fraction of the satellite's full resolution.

So it is kind of fitting that the first public image taken by the new DSS Ltd should be from a satellite that the pedestal was originally built to service, and given that satellite is now almost 21 years old it is able to buy us a celebratory drink!

Image from the first overhead pass showing UK

DSS Ltd is one year old! (24 July 2020)

We are making progress on the new site and now have the equipment room wired for 3-phase power and hope to have antennas on concrete plinths within the next couple of weeks to allow for refurbishment and testing. There are still many small jobs to sort out and various key tasks have been delayed by the current pandemic, but we are seeing light at the end of the tunnel.

This web site, and the bigger task of resurrecting what was Scotland's only significant ground station, are still very much "work in progress" so please be patient with us!

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