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Open a Discussion / Accidental illumination of other satellites
« Last post by danielhampf on February 12, 2024, 09:52:38 AM »
Hello all,

I keep being asked (every few years or so), if there is a danger of our ranging laser accidently hitting another satellite. Of course we know what we are tracking, and if we are not tracking, the laser is off.

But- satellites may pass in front of each other. Some random third-party satellite may be caught in the beam.

Has anybody ever made a study on this? What is the likelyhood? Especially with stronger laser for space debris or the moon, I suppose you really don't want to catch a down-looking Earth observation or spy satellite?

Lasers / Re: Laser manufacturers for SLR
« Last post by Matt Wilkinson on February 02, 2023, 10:57:55 AM »
Hi Arttu

Thanks for posting this. We are also thinking at Herstmonceux about our next laser and looking at the choices out there. Our HighQ 2kHz laser works, but is no longer supported.

Some options:

If you can decide what fire rates and pulse energies you want then the choices become easier. We would also be interested in IR operations.

Lasers / Laser manufacturers for SLR
« Last post by ArttuR-H on January 25, 2023, 09:01:35 AM »
Hello all,
I thought I will also ask from here for suggestions for suitable SLR lasers, as they seem rather hard to find and get.
Even though our station hasn't been operational for almost two decades (!), our HighQ 2kHz laser is degrading and spare parts are hard to get, hence we are looking for a replacement with somewhat similar specs (kHz, ~10ps, ~0.5mJ). The response from HiqhQ was that they are not providing any support or new suitable models.
So I've been asking around at ILRS meetings etc. and found out about Passat LTD, Ekspla, Innolas, Photonics, maybe Alphalas, I'm shure that there are other options as well, so does someone have some great suggestion which they would like to share?
I believe that our station is not the only one who are looking for a new laser.
All help is much appreciated!
Arttu, Metsähovi 
Telescopes / Anti-reflection coating for flat glass
« Last post by pywang on December 15, 2022, 12:25:12 PM »
Hi all,

In front of our Cassegrain telescope there is a protecting flat glass.
After celebrating its 40 years birthday we are thinking about re-coating it.
It has a size of 50 cm in diameter and 1 cm in thickness, and we need broadband anti-reflection coating on its both sides.
Does anybody have good experiences with some companies?
Thanks in advance!

best regard, Peiyuan Wang from SLR Graz
Dear SLR Station colleagues,

After a few years' break, a number of "station x satellite" systematic residual charts are created using one year data from July 2021 to June 2022.  See you at my poster in Guadalajara or online (

What's new in 2022: ITRF2020 velocity and PSD.  Rodriguez's CoM corrections.  GOCO6S gravity model.  LAGEOS-1 and -2 handled separately.

I am still making the poster and the link will be posted here later.  It is impossible to include all these charts in the poster, so please have a look in advance.

See you in Spain,
Toshimichi Otsubo (
Hitotsubashi University
Lasers / Laser Profiling paper
« Last post by pywang on June 10, 2022, 11:38:15 AM »

Former time it was very common to use a kind of special paper (e.g. Kodak Linograph 1895) to check the dye laser profile.
Does anybody know how/where to order such paper now?
Or any alternatives?
Is Baryta coated paper applicable?


Peiyuan Wang
Data and Software Questions / Re: - New Release 1.2
« Last post by Matt Wilkinson on June 01, 2022, 10:06:36 AM »
An update is now available on the ILRS website

The update includes the following changes:
Version 1.2.1
    --    CPF interpolation replaced with high order polynomial fit. This is to provide better prediciton values and to remove some actifacts in range residuals.
    --    Update matplotlib subplot axis referencing method to work with the latest versions.
Data and Software Questions / Re: - New Release 1.2
« Last post by DanielK on April 28, 2022, 12:05:17 AM »
Awesome, thank you so much!
Open a Discussion / Re: How does an SLR station affect the local bird population?
« Last post by sandmann on March 08, 2022, 04:43:42 PM »
Hi there Ole,
No real studies from my time at Yarragadee, but anecdotally, they seem to enjoy flying through the beam. I would notice around sunset time, some increase in bird activity around the telescope. It may have had nothing to do with the laser at all...
The best was when they would use the all-sky camera as a perch, and we could get a very wide angle view of the underneath of a bird. :)
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