More APPM Results -- Can Someone Help Me Understand This?


Don Anderson
 

I don't believe USNO B1.0 is even available for download from USNO anymore. One may be able to get it somewhere else.
In any case, if one is looking for super accurate plate solves, the latest and greatest database is the Atlas-REFCAT2 which uses data from the ATLAS Pathfinder and PanSTARS and GAIA surveys.

Don Anderson


On Friday, April 23, 2021, 07:14:05 a.m. MDT, Ray Gralak <iogroups@...> wrote:


Hi Don,

> USNO-B1.0 has been taken off line by USNO. The only way to use B 1.0 is if you have a local version on you
> computer.

USNO B1.0 is over 80 GBytes, consuming too much bandwidth to download from the USNO website.

Unfortunately, that leaves A2.0 as the outdated alternative, so UCAC4 is the better choice now.

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Don Anderson via groups.io
> Sent: Thursday, April 22, 2021 2:08 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> USNO-B1.0 has been taken off line by USNO. The only way to use B 1.0 is if you have a local version on you
> computer.
>
> Don Anderson
>
>
> On Thursday, April 22, 2021, 01:32:49 p.m. MDT, Ray Gralak <iogroups@...> wrote:
>
>
> > Ray i think that comment refers to  USNO-SA2.0
> >
> > USNO-SA2.0 is a subset of USNO-A2.0
>
> Yes, that is true about SA2.0, but A2.0 has been superseded by USNO-B1.0.
>
> -Ray
>
> > -----Original Message-----
> > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
> > Sent: Thursday, April 22, 2021 12:17 PM
> > To: main@ap-gto.groups.io
> > Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
> >
> > Ray i think that comment refers to  USNO-SA2.0
> >
> > USNO-SA2.0 is a subset of USNO-A2.0
> >
> >
> > On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@...> wrote:
> >
> >
> >    > For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
> >
> >    Bad information maybe?
> >
> >    According to the navy.mil website, USNO A2.0 is outdated:
> >
> >    https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2
> >
> >    -Ray
> >
> >
> >
> >    > -----Original Message-----
> >    > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
> >    > Sent: Thursday, April 22, 2021 12:05 PM
> >    > To: main@ap-gto.groups.io
> >    > Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
> >    >
> >    > For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
> >    >
> >    >
> >    >
> >    > Regards,
> >    >
> >    >
> >    >
> >    > George
> >    >
> >    >
> >    >
> >    > George Whitney
> >    >
> >    > Astro-Physics, Inc.
> >    >
> >    > Phone:  815-222-6538 (direct line)
> >    >
> >    > Phone:  815-282-1513 (office)
> >    >
> >    > Email:  george@... <mailto:george@...>
> >    >
> >    >
> >    >
> >    > From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
> >    > Sent: Thursday, April 22, 2021 1:49 PM
> >    > To: main@ap-gto.groups.io
> >    > Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
> >    >
> >    >
> >    >
> >    > BTW, I am using PinPoint and they do NOT recommend UCAV4.
> >    >
> >    >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > --
> >
> > Brian
> >
> >
> >
> > Brian Valente
> > portfolio brianvalentephotography.com  <http://brianvalentephotography.com>
> >
>
>
>
>
>
>
>
>







Ray Gralak
 

Hi Don,

USNO-B1.0 has been taken off line by USNO. The only way to use B 1.0 is if you have a local version on you
computer.
USNO B1.0 is over 80 GBytes, consuming too much bandwidth to download from the USNO website.

Unfortunately, that leaves A2.0 as the outdated alternative, so UCAC4 is the better choice now.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Don Anderson via groups.io
Sent: Thursday, April 22, 2021 2:08 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

USNO-B1.0 has been taken off line by USNO. The only way to use B 1.0 is if you have a local version on you
computer.

Don Anderson


On Thursday, April 22, 2021, 01:32:49 p.m. MDT, Ray Gralak <iogroups@siriusimaging.com> wrote:


Ray i think that comment refers to USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0
Yes, that is true about SA2.0, but A2.0 has been superseded by USNO-B1.0.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
Sent: Thursday, April 22, 2021 12:17 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

Ray i think that comment refers to USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0


On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@siriusimaging.com> wrote:


> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.

Bad information maybe?

According to the navy.mil website, USNO A2.0 is outdated:

https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2

-Ray



> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
> Sent: Thursday, April 22, 2021 12:05 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>
>
>
> Regards,
>
>
>
> George
>
>
>
> George Whitney
>
> Astro-Physics, Inc.
>
> Phone: 815-222-6538 (direct line)
>
> Phone: 815-282-1513 (office)
>
> Email: george@astro-physics.com <mailto:george@astro-physics.com>
>
>
>
> From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
> Sent: Thursday, April 22, 2021 1:49 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
>
>
> BTW, I am using PinPoint and they do NOT recommend UCAV4.
>
>










--

Brian



Brian Valente
portfolio brianvalentephotography.com <http://brianvalentephotography.com>







Don Anderson
 

USNO-B1.0 has been taken off line by USNO. The only way to use B 1.0 is if you have a local version on you computer.

Don Anderson


On Thursday, April 22, 2021, 01:32:49 p.m. MDT, Ray Gralak <iogroups@...> wrote:


> Ray i think that comment refers to  USNO-SA2.0
>
> USNO-SA2.0 is a subset of USNO-A2.0

Yes, that is true about SA2.0, but A2.0 has been superseded by USNO-B1.0.

-Ray

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
> Sent: Thursday, April 22, 2021 12:17 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> Ray i think that comment refers to  USNO-SA2.0
>
> USNO-SA2.0 is a subset of USNO-A2.0
>
>
> On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@...> wrote:
>
>
>     > For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>
>     Bad information maybe?
>
>     According to the navy.mil website, USNO A2.0 is outdated:
>
>     https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2
>
>     -Ray
>
>
>
>     > -----Original Message-----
>     > From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
>     > Sent: Thursday, April 22, 2021 12:05 PM
>     > To: main@ap-gto.groups.io
>     > Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>     >
>     > For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>     >
>     >
>     >
>     > Regards,
>     >
>     >
>     >
>     > George
>     >
>     >
>     >
>     > George Whitney
>     >
>     > Astro-Physics, Inc.
>     >
>     > Phone:  815-222-6538 (direct line)
>     >
>     > Phone:  815-282-1513 (office)
>     >
>     > Email:  george@... <mailto:george@...>
>     >
>     >
>     >
>     > From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
>     > Sent: Thursday, April 22, 2021 1:49 PM
>     > To: main@ap-gto.groups.io
>     > Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>     >
>     >
>     >
>     > BTW, I am using PinPoint and they do NOT recommend UCAV4.
>     >
>     >
>
>
>
>
>
>
>
>
>
>
> --
>
> Brian
>
>
>
> Brian Valente
> portfolio brianvalentephotography.com  <http://brianvalentephotography.com>
>







Ray Gralak
 

BTW,

USNO A2.0 has an accuracy of 0.25 arc-secs and doesn't account for stellar proper-motion.

UCAC4 has an accuracy of 0.05-0.10 arc-sec and accounts for stellar proper-motion.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
Sent: Thursday, April 22, 2021 12:17 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

Ray i think that comment refers to USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0


On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@siriusimaging.com> wrote:


> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.

Bad information maybe?

According to the navy.mil website, USNO A2.0 is outdated:

https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2

-Ray



> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
> Sent: Thursday, April 22, 2021 12:05 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>
>
>
> Regards,
>
>
>
> George
>
>
>
> George Whitney
>
> Astro-Physics, Inc.
>
> Phone: 815-222-6538 (direct line)
>
> Phone: 815-282-1513 (office)
>
> Email: george@astro-physics.com <mailto:george@astro-physics.com>
>
>
>
> From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
> Sent: Thursday, April 22, 2021 1:49 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
>
>
> BTW, I am using PinPoint and they do NOT recommend UCAV4.
>
>










--

Brian



Brian Valente
portfolio brianvalentephotography.com <http://brianvalentephotography.com>


Ray Gralak
 

Ray i think that comment refers to USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0
Yes, that is true about SA2.0, but A2.0 has been superseded by USNO-B1.0.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Brian Valente
Sent: Thursday, April 22, 2021 12:17 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

Ray i think that comment refers to USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0


On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@siriusimaging.com> wrote:


> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.

Bad information maybe?

According to the navy.mil website, USNO A2.0 is outdated:

https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2

-Ray



> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
> Sent: Thursday, April 22, 2021 12:05 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>
>
>
> Regards,
>
>
>
> George
>
>
>
> George Whitney
>
> Astro-Physics, Inc.
>
> Phone: 815-222-6538 (direct line)
>
> Phone: 815-282-1513 (office)
>
> Email: george@astro-physics.com <mailto:george@astro-physics.com>
>
>
>
> From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
> Sent: Thursday, April 22, 2021 1:49 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
>
>
> BTW, I am using PinPoint and they do NOT recommend UCAV4.
>
>










--

Brian



Brian Valente
portfolio brianvalentephotography.com <http://brianvalentephotography.com>


 

Ray i think that comment refers to  USNO-SA2.0

USNO-SA2.0 is a subset of USNO-A2.0


On Thu, Apr 22, 2021 at 12:13 PM Ray Gralak <iogroups@...> wrote:
> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.

Bad information maybe?

According to the navy.mil website, USNO A2.0 is outdated:

https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2

-Ray



> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
> Sent: Thursday, April 22, 2021 12:05 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
> For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
>
>
>
> Regards,
>
>
>
> George
>
>
>
> George Whitney
>
> Astro-Physics, Inc.
>
> Phone:  815-222-6538 (direct line)
>
> Phone:  815-282-1513 (office)
>
> Email:  george@... <mailto:george@...>
>
>
>
> From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
> Sent: Thursday, April 22, 2021 1:49 PM
> To: main@ap-gto.groups.io
> Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?
>
>
>
> BTW, I am using PinPoint and they do NOT recommend UCAV4.
>
>








--
Brian 



Brian Valente


Ray Gralak
 

For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.
Bad information maybe?

According to the navy.mil website, USNO A2.0 is outdated:

https://www.usno.navy.mil/USNO/astrometry/information/catalog-info#usnoa2

-Ray



-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of George
Sent: Thursday, April 22, 2021 12:05 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.



Regards,



George



George Whitney

Astro-Physics, Inc.

Phone: 815-222-6538 (direct line)

Phone: 815-282-1513 (office)

Email: george@astro-physics.com <mailto:george@astro-physics.com>



From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
Sent: Thursday, April 22, 2021 1:49 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?



BTW, I am using PinPoint and they do NOT recommend UCAV4.


George
 

For small fields of view with Pin Point, the USNO-A2.0 catalog is recommended by DC3 Dreams.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of mjb87 via groups.io
Sent: Thursday, April 22, 2021 1:49 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

 

BTW, I am using PinPoint and they do NOT recommend UCAV4.


mjb87@...
 

BTW, I am using PinPoint and they do NOT recommend UCAV4.


Greg McCall
 

Ray, how do you know when to use APM or UCAC4?
(or a link to info)


mjb87@...
 

Thanks, Ray. I'll look into UCAC4. I will also reconfirm that the mount is well balanced, check orthogonality and reconfirm clutches are tight. (They appeared to be tight last night.)  I'm also getting a mono camera with larger pixels (5.86 vs. 3.8) which should make things slightly easier and more straightforward when setting pixel size. Next clear night I'll run some tests, if I can get solutions, on 1x1 binning to see what APPM reports as image scale.

BTW, one of the great features of APPM is the ability to a file of saved failed images from the comfort of home the next day. It allows me to tweak settings for maximum probability of getting solutions. Very nice.

Marty


Ray Gralak
 

BTW, at that image scale you should probably by using the UCAC4 catalog, if your plate solver can use it.

-Ray

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of mjb87 via groups.io
Sent: Tuesday, April 20, 2021 6:55 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

Running an APPM session with a f/10 (native f/15 with 0.67 focal reducer) Cassegrain on an 1100 using an
ASI1600MC-Cool. Image scale is 0.26 but because this is a OSC at Ray's suggestion I used 0.52 for both X
and Y scale. Other settings were generally standard except the max catalog magnitude was reduced to 12.
(This seems to avoid a lot of checkpoint timing errors.) This was during a half-moon almost directly overhead.
Not ideal conditions. A bit of wind. I can't figure out how to manually set temperature, pressure and humidity so
the default of 10 was used when it was closer to 18.

The run on the east side made sense. Most errors with a couple of dozen arcminutes.



Things went crazy on the west side, reporting pointing errors of 10 or 15 degrees!



I installed this model and then pointed in the west and did a plate-solve and recal and got an error telling me
the platesolve-based correction of 15 degrees was more than the maximum allowed. So something is wrong
here.

The physical setup of the telescope on the mount seems appropriate -- for sure no 15 degree misalignment in
orthogonality. The primary mirror is fixed. Collimation is good -- checked a week ago. The polar alignment is
good -- ran a session with Polemaster yesterday and checked with RAPAS today.

Am I missing something obvious here?

Marty


Ray Gralak
 

Hi Marty,

 

> Running an APPM session with a f/10 (native f/15 with 0.67 focal reducer) Cassegrain on an 1100 using an

> ASI1600MC-Cool. Image scale is 0.26 but because this is a OSC at Ray's suggestion I used 0.52 for both X and Y

> scale.

 

Actually, it was my suggestion based on what you described. I’m not sure it was a correct suggestion. J

 

With APPM’s camera settings set to 1x binning, what image scale does a plate solve return when you click the “Plate Solve” button on APPM’s setup tab? That’s the value you should enter for x and Y scale on APPM’s “Plate Solve Settings” tab.

 

> Things went crazy on the west side, reporting pointing errors of 10 or 15 degrees!

 

Maybe the RA clutch is slipping?

 

> I can't figure out how to manually set temperature, pressure and humidity so the default of 10 was used

> when it was closer to 18.

 

You can manually set Temperature and Pressure in APCC as in this screen shot:

 

 

You cannot set humidity manually, but it has very little effect on the refraction calculation.

 

-Ray

 

 

> -----Original Message-----

> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of mjb87 via groups.io

> Sent: Tuesday, April 20, 2021 6:55 PM

> To: main@ap-gto.groups.io

> Subject: [ap-gto] More APPM Results -- Can Someone Help Me Understand This?

>

> Running an APPM session with a f/10 (native f/15 with 0.67 focal reducer) Cassegrain on an 1100 using an

> ASI1600MC-Cool. Image scale is 0.26 but because this is a OSC at Ray's suggestion I used 0.52 for both X and Y

> scale. Other settings were generally standard except the max catalog magnitude was reduced to 12. (This seems to

> avoid a lot of checkpoint timing errors.)  This was during a half-moon almost directly overhead. Not ideal conditions. A

> bit of wind. I can't figure out how to manually set temperature, pressure and humidity so the default of 10 was used

> when it was closer to 18.

>

> The run on the east side made sense. Most errors with a couple of dozen arcminutes.

>

>

>

> Things went crazy on the west side, reporting pointing errors of 10 or 15 degrees!

>

>

>

> I installed this model and then pointed in the west and did a plate-solve and recal and got an error telling me the

> platesolve-based correction of 15 degrees was more than the maximum allowed. So something is wrong here.

>

> The physical setup of the telescope on the mount seems appropriate -- for sure no 15 degree misalignment in

> orthogonality. The primary mirror is fixed. Collimation is good -- checked a week ago. The polar alignment is good --

> ran a session with Polemaster yesterday and checked with RAPAS today.

>

> Am I missing something obvious here?

>

> Marty


mjb87@...
 

Running an APPM session with a f/10 (native f/15 with 0.67 focal reducer) Cassegrain on an 1100 using an ASI1600MC-Cool. Image scale is 0.26 but because this is a OSC at Ray's suggestion I used 0.52 for both X and Y scale. Other settings were generally standard except the max catalog magnitude was reduced to 12. (This seems to avoid a lot of checkpoint timing errors.)  This was during a half-moon almost directly overhead. Not ideal conditions. A bit of wind. I can't figure out how to manually set temperature, pressure and humidity so the default of 10 was used when it was closer to 18.

The run on the east side made sense. Most errors with a couple of dozen arcminutes. 



Things went crazy on the west side, reporting pointing errors of 10 or 15 degrees!



I installed this model and then pointed in the west and did a plate-solve and recal and got an error telling me the platesolve-based correction of 15 degrees was more than the maximum allowed. So something is wrong here.

The physical setup of the telescope on the mount seems appropriate -- for sure no 15 degree misalignment in orthogonality. The primary mirror is fixed. Collimation is good -- checked a week ago. The polar alignment is good -- ran a session with Polemaster yesterday and checked with RAPAS today.

Am I missing something obvious here?

Marty