Date   

Re: Confused about Metop

Graham Woolf
 

Hi

That all makes sense -thanks

Graham


FY3D

Graham Woolf
 

Hi

I notice  that there hasnt been any FY3D data now since about the 15th November

Does anyone know why - I cant seem to find anything on the UNS

Regards

Graham


Re: Historic document about first US imaging (reconnaissance) satellites

Ferdinand Valk
 

Thanks for sharing Luis, muy apreciado.

 

Ferdinand

 

From: MSG-1@groups.io On Behalf Of Luis Fernandez
Sent: Monday, 22 November, 2021 15:47
To: MSG-1@groups.io
Subject: [MSG-1] Historic document about first US imaging (reconnaissance) satellites

 

Hi group

The US goverment has recently released to public access a number of classified documents
A good friend inmediately sent me a copy of a very interesting pdf. It was published by the
US National Reconnaissance Office in the early 80's and covers the evolution of US "spy" satellites
from the early CORONA to the KENNEN/KH-11, which was state of the art in 1977

I'm sure you will enjoy reading it. Really amazing how big the technical problems were and how they managed to
overcome then and contributed to develop new technologies we actually enjoy

You can download it from my personal Dropbox with this link
https://www.dropbox.com/s/s3h0scyyl9tcrdh/The%20Era%20Before%20KENNEN%20KH-11.pdf?dl=0

73 de Luis
EA5DOM


Historic document about first US imaging (reconnaissance) satellites

Luis Fernandez
 

Hi group

The US goverment has recently released to public access a number of classified documents
A good friend inmediately sent me a copy of a very interesting pdf. It was published by the
US National Reconnaissance Office in the early 80's and covers the evolution of US "spy" satellites
from the early CORONA to the KENNEN/KH-11, which was state of the art in 1977

I'm sure you will enjoy reading it. Really amazing how big the technical problems were and how they managed to
overcome then and contributed to develop new technologies we actually enjoy

You can download it from my personal Dropbox with this link
https://www.dropbox.com/s/s3h0scyyl9tcrdh/The%20Era%20Before%20KENNEN%20KH-11.pdf?dl=0

73 de Luis
EA5DOM


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 20/11/2021 12:44, CrazyCat wrote:
Two instances BDADataEx (two precess with own settings) work with separate TAP-DVB virtual network interface (not use any irq)
Thanks, CrazyCat.

Understood.

I've tried setting the processor affinity by hand with the existing BDADataEx (1.1.4.9) and will monitor the results.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: TBS 6903 tuner allocations

CrazyCat
 

Two instances BDADataEx (two precess with own settings) work with separate TAP-DVB virtual network interface (not use any irq)


On Sat, Nov 20, 2021 at 12:47 PM, Ernst Lobsiger wrote:
Sorry to ask this: Do you run 2 instances of BDADataEx if you receive 2 transponders? Or do you only need 2 Tap Adapters?

If you run 2 BDADataEx processes then the new switch most probably pins the process (or Tap Adapter?) and not the ECP3 interrupt!
I would not make any sense to pin the ECP3 interrupt in different ways from the 2 BDADataEx panels. To run two processes of
BDADataEx pined to different cores might be worth to try.


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 20/11/2021 10:47, Ernst Lobsiger via groups.io wrote:
David,

Sorry to ask this: Do you run 2 instances of BDADataEx if you receive 2
transponders? Or do you only need 2 Tap Adapters?

If you run 2 BDADataEx processes then the new switch most probably pins the
process (or Tap Adapter?) and not the ECP3 interrupt!
I would not make any sense to pin the ECP3 interrupt in different ways from the
2 BDADataEx panels. To run two processes of
BDADataEx pined to different cores might be worth to try.

Cheers,
Ernst
_._,_._,
Ernst,

You run a program (effectively installing a device) which adds a second TAP
device. You then run two instances of BDADataEx (two different tuner
frequencies) and (I believe) each instance attaches to a different TAP "device".

I'll have to try the two affinities, but without making it exclusive. I we
could identify the continuous missed & recovered packets I feel that something
useful would have been learnt.

I think I'm gradually understanding a little better what happens. (In the past
Have have modified device drivers for VAX/VMS so I have worked at that level,
some years ago, though).

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: TBS 6903 tuner allocations

Ernst Lobsiger
 

David,

Sorry to ask this: Do you run 2 instances of BDADataEx if you receive 2 transponders? Or do you only need 2 Tap Adapters?

If you run 2 BDADataEx processes then the new switch most probably pins the process (or Tap Adapter?) and not the ECP3 interrupt!
I would not make any sense to pin the ECP3 interrupt in different ways from the 2 BDADataEx panels. To run two processes of
BDADataEx pined to different cores might be worth to try.

Cheers,
Ernst


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 20/11/2021 09:35, Ernst Lobsiger via groups.io wrote:
David,

under GNU/Linux you have both and these are independant choices. You can tell a
process to run on one core. This can e.g. be the HVS-2 client. Maybe under
Windows this could also be BDADataEx.
I have never experimented with this feature. On the other hand you can tell the
kernel to use always the same core to serve a special interrupt. In
/proc/interrupts all devices and their interrupts are listed.
In the case of a TBS-6903 probably the busiest interrupt will be the one used
by the ECP3 PCIe bridge for DMA transfer of a bunch of MPE packets to the
kernel. The kernel then sorts and assembles these
MPE (188Bytes) packets per PID to UDP packets that finally are sent to an
internal interface dvbond0. Under Windows that's probably what BDA (Microsoft)
and BDADataEx (CrazyCat, sounds to me like
"Extract Data from BDA") does. Now the busiest interrupts (ECP3, HDD/SSD, NIC,
USB?) should not occurr on the same core. I have a script that pins these
interrupts as far as possible to different cores.

This should be possible under Windows as well. The question is now what the new
BDADataEx switch does. CrazyCat should please explain whether this pins
BDADataEx or the ECP3 interrupt to some core ?

Cheers,
Ernst

Attached: Output of # cat /proc/interrupts of my receiver Kallisto (Devuan 3.0,
Beowulf, GNU/Linux, using a TBS-6909X, note the tbsecp3 entry):
[]

David, to begin with you should have a similar interrupt list as above from
Windows 10 to see whether there is something to optimize at all.
Thanks for that, Ernst. I can get the list of interrupt sources but not their
associations. My system has only 4 cores, and my feeling is that if I dedicate
two cores exclusively to the two TAP devices that leaves the system with just
two cores for everything else, and I wonder whether that would be the best
balance. With 8 cores you're only dedicating 25% of the resources.

It would be interesting to hear what results CrazyCat has seen.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: TBS 6903 tuner allocations

Ernst Lobsiger
 

On Sat, Nov 20, 2021 at 12:52 AM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
Now that CrazyCat has the affinity ability that may help, but I don't know
enough about Windows internals (even though I have the book) to know whether
there should be any relation between program affinity and interrupt affinity.
David,

under GNU/Linux you have both and these are independant choices. You can tell a process to run on one core. This can e.g. be the HVS-2 client. Maybe under Windows this could also be BDADataEx.
I have never experimented with this feature. On the other hand you can tell the kernel to use always the same core to serve a special interrupt. In /proc/interrupts all devices and their interrupts are listed.
In the case of a TBS-6903 probably the busiest interrupt will be the one used by the ECP3 PCIe bridge for DMA transfer of a bunch of MPE packets to the kernel. The kernel then sorts and assembles these
MPE (188Bytes) packets per PID to UDP packets that finally are sent to an internal interface dvbond0. Under Windows that's probably what BDA (Microsoft) and BDADataEx (CrazyCat, sounds to me like
"Extract Data from BDA") does. Now the busiest interrupts (ECP3, HDD/SSD, NIC, USB?) should not occurr on the same core. I have a script that pins these interrupts as far as possible to different cores.

This should be possible under Windows as well. The question is now what the new BDADataEx switch does. CrazyCat should please explain whether this pins BDADataEx or the ECP3 interrupt to some core ?

Cheers,
Ernst

Attached: Output of # cat /proc/interrupts of my receiver Kallisto (Devuan 3.0, Beowulf, GNU/Linux, using a TBS-6909X, note the tbsecp3 entry):

           CPU0       CPU1       CPU2       CPU3       CPU4       CPU5       CPU6       CPU7       
  0:          8          0          0          0          0          0          0          0  IR-IO-APIC   2-edge      timer
  4:          0          0          0    1318049          0          0          0          0  IR-IO-APIC   4-edge      ttyS0
  5:          0          0          0          0          0          0          0          0  IR-IO-APIC   5-edge      parport0
  8:          0          0          0          0          0         21          0          0  IR-IO-APIC   8-edge      rtc0
  9:          0          0          0          0          0          0          0          0  IR-IO-APIC   9-fasteoi   acpi
 16:          0         31          0          0          0          0          0          0  IR-IO-APIC  16-fasteoi   ehci_hcd:usb1
 17:         62          0          0          0          0          0          0          0  IR-IO-APIC  17-fasteoi   snd_hda_intel:card1
 18:          0          0          0          0          0          0          0          0  IR-IO-APIC  18-fasteoi   i801_smbus
 19:          0 1415776871          0          0          0          0          0          0  IR-IO-APIC  19-fasteoi   tbsecp3
 23:          0          0          0          0    3267825          0          0          0  IR-IO-APIC  23-fasteoi   ehci_hcd:usb3
 24:          0          0          0          0          0          0          0          0  DMAR-MSI   0-edge      dmar0
 25:          0          0          0          0          0          0          0          0  IR-PCI-MSI 16384-edge      PCIe PME
 26:          0          0          0          0          0          0          0          0  IR-PCI-MSI 458752-edge      PCIe PME
 27:          0          0          0          0          0          0          0          0  IR-PCI-MSI 473088-edge      PCIe PME
 28:          0          0          0          0          0          0          0    3255510  IR-PCI-MSI 409600-edge      eth0
 29:          0          0   29746433          0          0          0          0          0  IR-PCI-MSI 512000-edge      ahci[0000:00:1f.2]
 30:          0          0          0          0          0          0          0          0  IR-PCI-MSI 327680-edge      xhci_hcd
 31:          0          0          0          0          0         23          0          0  IR-PCI-MSI 360448-edge      mei_me
 32:          0          0          0          0          0          0          0        242  IR-PCI-MSI 442368-edge      snd_hda_intel:card0
 33:          0          0    4060863          0          0          0          0          0  IR-PCI-MSI 524288-edge      nvkm
NMI:      16145      23462      21583      22693      20261      19027      15918      15328   Non-maskable interrupts
LOC:  153775488  586746645  398399531  388269865  325950027  253666782  202693335  176936583   Local timer interrupts
SPU:          0          0          0          0          0          0          0          0   Spurious interrupts
PMI:      16145      23462      21583      22693      20261      19027      15918      15328   Performance monitoring interrupts
IWI:          0          5          0          0          0          0          0          0   IRQ work interrupts
RTR:          0          0          0          0          0          0          0          0   APIC ICR read retries
RES:  117490731    5532105   18876446    9023898    5781590    4223042    3687445    3482737   Rescheduling interrupts
CAL:   28108361   26115001   28588588   28688108   27971425   27915887   27513570   27572657   Function call interrupts
TLB:   28881833   26792476   29240539   29311575   28567330   28482494   28063990   28101568   TLB shootdowns
TRM:          0          0          0          0          0          0          0          0   Thermal event interrupts
THR:          0          0          0          0          0          0          0          0   Threshold APIC interrupts
DFR:          0          0          0          0          0          0          0          0   Deferred Error APIC interrupts
MCE:          0          0          0          0          0          0          0          0   Machine check exceptions
MCP:       6524       6525       6525       6525       6525       6525       6525       6525   Machine check polls
ERR:          0
MIS:          0
PIN:          0          0          0          0          0          0          0          0   Posted-interrupt notification event
NPI:          0          0          0          0          0          0          0          0   Nested posted-interrupt event
PIW:          0          0          0          0          0          0          0          0   Posted-interrupt wakeup event

David, to begin with you should have a similar interrupt list as above from Windows 10 to see whether there is something to optimize at all.


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 17/11/2021 16:57, Ernst Lobsiger via groups.io wrote:
David,

here is a tool for interrupt affinity under Windows

https://www.techpowerup.com/download/microsoft-interrupt-affinity-tool/
<https://www.techpowerup.com/download/microsoft-interrupt-affinity-tool/>

use it at your own risk and peril :-).

Cheers,
Ernst
Ernst,

Many thanks for that. Unfortunately the program is from 2007 and hasn't been
updated. When running it you get the device list, but not the interrupt mask -
"the registry value is an unexpected type".

The device list is quite long - longer than I expected - but it shows just one
TBS6903 device with a physical PCI address, but two TAP adapters without a
hardware address (just /device/00000003 or something like that).

Now that CrazyCat has the affinity ability that may help, but I don't know
enough about Windows internals (even though I have the book) to know whether
there should be any relation between program affinity and interrupt affinity.
Something in me says there won't be, as interrupts could occur at any time, and
Windows would simply choose the least busy processor to handle them, and then
notify the the process expecting that interrupt that its data is ready.

As this is UDP data coming in, I guess BDADataEx converts the DVB stream into a
series of UDP packets and sends them to Windows as if they come from a network
device. As there is (apparently) just one hardware device as seen by Windows,
perhaps having two different affinities for the two BDADataEx instances is a
good idea, assuming that the two processors nominated are actually free, or the
least loaded at that instant!

Perhaps best to let Windows decide on this four-processor system!

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 19/11/2021 17:56, CrazyCat wrote:
Hi David,

I make test build BDADataEx 1.4.12 with *Affinity* option
http://crazycat69.narod.ru/sattelite/DVBDataEx/test/BDADataEx.rar
<http://crazycat69.narod.ru/sattelite/DVBDataEx/test/BDADataEx.rar>
Many thanks for that, CrazyCat. I hope to test this, but I need to ask Ernst a
question first.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: TBS 6903 tuner allocations

CrazyCat
 

Hi David,

I make test build BDADataEx 1.4.12 with Affinity option
http://crazycat69.narod.ru/sattelite/DVBDataEx/test/BDADataEx.rar


On Wed, Nov 17, 2021 at 04:52 PM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
On my particular system there are 4 cores. The HVS-1 and HVS-2 TelliCast
processes are allowed to run on any core. The two BDADataEx processes and both
only allowed to run on Core 0 and both are at Realtime priority. I wonder
whether separating the affinity of the two BDADataEx processes would help? I
don't know where the affinity is set - it may be within the BDADataEx.exe itself?


Re: TBS 6903 tuner allocations

Ernst Lobsiger
 

On Wed, Nov 17, 2021 at 06:52 AM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
Windows has processor affinity, yes, but I don't know about interrupt affinity.
David,

here is a tool for interrupt affinity under Windows

https://www.techpowerup.com/download/microsoft-interrupt-affinity-tool/

use it at your own risk and peril :-).

Cheers,
Ernst


Re: Dual Link Margin script SR1lm.pl

Thorsten Miglus
 

Ernst,

the NOVRA receiver provide no link margin values.
So I have defined my own values:
For BAS I subtract 6.7 from SNR.
For HVS I subtract 10.5 from SNR.
I observed, that error free reception above this values is possible.

Cheers,
Thorsten


On Tue, Nov 16, 2021 at 09:02 PM, Ernst Lobsiger wrote:
David,

yes the LM of HVS is normally the problem. With a reasonably sized antenna BAS almost always has a considerable LM.
Of course the constants I use are only "empirical" as far as I have found those from looking at an SR1 status display.
The SR1 people have certainly calculated those from MODCOD and maybe max symbol rate and other HW settings.

FYI: Yesterday I also did the test with two other SR1 EUMETCast receiver stations on your page:

Loughborough SR1 #1:   SNR (EsNo) = 13.9 dB   /  LMbas = 8.0 dB  /  LM hvs-1 = 4.6 dB
Rungsted Ayecka SR1:   SNR (EsNo) = 13.6 dB   /  LMbas = 7.7 dB  /  LM hvs-1 = 4.3 dB

Both SR1 receivers fulfill my simple equations.

But those do not work exactly with Thorsten's Novra S300N. The Novra staff has a slightly
different idea what LM = 0dB means. This might also be to some extent HW dependant.

Cheers,
Ernst


Re: TBS 6903 tuner allocations

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 16/11/2021 17:40, Ernst Lobsiger via groups.io wrote:
David,

I think it's not a demod problem but a PCIe bridge problem. As I said in a post
before this ECP3 chip (common to all TBS PCIe cards issued after the TBS6983
Arne uses) has 8 "channels" with seperate DMA buffers for up to 8 demodulators.
If I got you right you did put T2 or T1  on demod0 and the problem was always
there. This is always "channel0" of the ECP3 chip. I also notet that most of
your lost packets bursts on HVS-2 are in sync with spikes of your HD/SSD read
usage.

Under GNU/Linux there is interrupt affinity. You can pin certain interrupts to
always use the same processor core. Your most frequent interrupts are probably
related to ECP3 DMA transfer of the TBS-card, to your NIC and to the HDD/ SSD.
Under GNU/Linux you can do as root a "# cat /proc/interrupts" to see who uses
what interrupts how often. The busiest interrupts should be on separate cores.
There should be a similar system information under Windows 10 somewhere.
While I can optimize interrupts with a simple bash script under GNU/Linux
Interrupt affinity under Windows 10 is probably registry stuff. So that's not
the first thing you want to touch. But try to find out what causes thes HDD/SSD
read spikes.


Good luck,
Ernst
Thanks for your comments, Ernst, and apologise for need them to be repeated!
Windows has processor affinity, yes, but I don't know about interrupt affinity.

On my particular system there are 4 cores. The HVS-1 and HVS-2 TelliCast
processes are allowed to run on any core. The two BDADataEx processes and both
only allowed to run on Core 0 and both are at Realtime priority. I wonder
whether separating the affinity of the two BDADataEx processes would help? I
don't know where the affinity is set - it may be within the BDADataEx.exe itself?

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: Dual Link Margin script SR1lm.pl

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 16/11/2021 20:02, Ernst Lobsiger via groups.io wrote:
David,

yes the LM of HVS is normally the problem. With a reasonably sized antenna BAS
almost always has a considerable LM.
Of course the constants I use are only "empirical" as far as I have found those
from looking at an SR1 status display.
The SR1 people have certainly calculated those from MODCOD and maybe max symbol
rate and other HW settings.

FYI: Yesterday I also did the test with two other SR1 EUMETCast receiver
stations on your page:

Loughborough SR1 #1:   SNR (EsNo) = 13.9 dB   /  LMbas = 8.0 dB  /  LM hvs-1 =
4.6 dB
Rungsted Ayecka SR1:   SNR (EsNo) = 13.6 dB   /  LMbas = 7.7 dB  /  LM hvs-1 =
4.3 dB

Both SR1 receivers fulfill my simple equations.

But those do not work exactly with Thorsten's Novra S300N. The Novra staff has
a slightly
different idea what LM = 0dB means. This might also be to some extent HW dependant.

Cheers,
Ernst
Yes, empirical, but good enough to compare across the same devices. My guess
is that the passband shape will come into it, and how that affects both the
noise distribution across the passband, and the shape of the recovered digital
signal. It wouldn't surprise me if different companies had different definitions.

Some definitions talk about "when the receiver stops working", but what does
that mean? With digital systems there isn't a sudden stop between LM := +0.1
dB and LM := -0.1 dB, so should the "acceptable" bit error rate come into the
definition?

I see the value of these measurements as being for individuals to watch for any
gradual degradation in their system or to monitor improvements they may make,
or for comparisons across Europe to answer questions such as "I live in
Helsinki - what dish might I need?".

The more monitoring stations sharing their data the better!

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: Pytroll/Satpy coordinates in scripts

Ernst Lobsiger
 

Daniele,

remember that it is of no use to have very big numbers of pixels. Only the aspect ratio of area-extent and image shape must match.
The example I started with has 1000 pixels for 300 km.This is 300m per pixel. Only Sentinel- 3A/B OLCI (EFR) has this resolution.
Meteosat has 3km resolution for all channels but HRV that has 1km resolution. This is at SubSatelltePoint (SSP) on the equator.
For Europe (slant view) the resolution is even less. So for 600km high x 300km wide imaged with SEVIRI even 600 x 300 pixels is
enough. The more pixels the longer the reprojection (resampling) with the Satpy script will take. It's good practice to have e.g.
italy1 with smaller image size for GEO sats and italy2 with 500m resolution for LEO sats like NOAA20 and SuomiNPP (VIIRS).

Regards,
Ernst


Re: Pytroll/Satpy coordinates in scripts

Daniele Guardigli
 

Thank you Ernst, it works! Now let's play with areas! 


Il giorno mer 17 nov 2021 alle ore 11:30 Ernst Lobsiger via groups.io <ernst.lobsiger=belponline.ch@groups.io> ha scritto:
Daniele,

In your personal   ...EMCtools/pppconfig/areas.yaml copy any whole area definition on top and edit it as the example below:

cyprus:                                                                        Change this to italy  (area name used in the script later)
  description: Do not buy a home ...                            Your personal comment goes here (anything)
  projection:
    proj: stere
    ellps: WGS84
    lat_0: 35.15                                                             Change this lat and lon in degrees (N/E positive) to what the center
    lon_0: 33.42                                                            of your map should be (use e.g. Google Earth to find lat and lon)
  shape:
    height: 1000                                                            This is your image height in pixels
    width: 1000                                                              This is your image width in pixels (without the legend at left)
  area_extent:
    lower_left_xy: [-150000.0, -150000.0]                     This is lower left corner (x,y) of the map from center (lat/lon) above     in Meters
    upper_right_xy: [150000.0, 150000.0]                    This is upper right corner (x,y) of the map from center (lat/lon) above  in Meters



All you have to take care is that your area_extent and the shape are in sync. Above the area_extent is square 300 x 300 km and shape is square 1000 x 1000 pixels.
If you make the area extent 600 km (high) and 300km (wide) then the image should be e.g. 2000 pixels high and 1000 pixels wide.  The lat/lon grid must cross in right
angles (stereographic projection used)! I suggest to begin with you just change the name of the area to italy and select the center (lat/lon). Then make a first image ...

Cheers,
Ernst



--
Daniele Guardigli


Re: Pytroll/Satpy coordinates in scripts

Ernst Lobsiger
 

Daniele,

In your personal   ...EMCtools/pppconfig/areas.yaml copy any whole area definition on top and edit it as the example below:

cyprus:                                                                        Change this to italy  (area name used in the script later)
  description: Do not buy a home ...                            Your personal comment goes here (anything)
  projection:
    proj: stere
    ellps: WGS84
    lat_0: 35.15                                                             Change this lat and lon in degrees (N/E positive) to what the center
    lon_0: 33.42                                                            of your map should be (use e.g. Google Earth to find lat and lon)
  shape:
    height: 1000                                                            This is your image height in pixels
    width: 1000                                                              This is your image width in pixels (without the legend at left)
  area_extent:
    lower_left_xy: [-150000.0, -150000.0]                     This is lower left corner (x,y) of the map from center (lat/lon) above     in Meters
    upper_right_xy: [150000.0, 150000.0]                    This is upper right corner (x,y) of the map from center (lat/lon) above  in Meters



All you have to take care is that your area_extent and the shape are in sync. Above the area_extent is square 300 x 300 km and shape is square 1000 x 1000 pixels.
If you make the area extent 600 km (high) and 300km (wide) then the image should be e.g. 2000 pixels high and 1000 pixels wide.  The lat/lon grid must cross in right
angles (stereographic projection used)! I suggest to begin with you just change the name of the area to italy and select the center (lat/lon). Then make a first image ...

Cheers,
Ernst

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