• I've heard that the peak data rate = X MB/sec (from where does this limit arise?)
• If true, then the peak data rate per baseline = (X MB/sec) / 2016 baselines = X/2.016 kB/sec
• If I want 8192 channels * 4 quadrants * 8 bytes (i.e. 4 bytes for real & 4 bytes for imaginary), then I need 262kB per baseline. So I am limited to T=(2016*0.262MB/X) = 528/X second integrations or longer.
• But the minimum dump time is listed as 0.512 seconds, so this implies that X needs to be 1031 MB/sec = 1 GB/sec.

• I've heard that the peak data rate = 60 MB/sec (from where does this limit arise?)
• If so, then the peak data rate per baseline with 50 antennas = (60 MB/sec) / 1225 baselines = 60/2.016 kB/sec = 30 kB/sec
• If I want 8192 channels * 4 quadrants * 8 bytes (i.e. 4 bytes for real & 4 bytes for imaginary), then I need 262kB per baseline. So I am limited to T=(1225*0.262MB/60) = 321/60 = 5.35 second integrations or longer.
• But the minimum dump time is listed as 0.512 seconds, so this implies that X needs to be 1031 MB/sec = 1 GB/sec when the data rate is upgraded in the future.

Comparison of ALMA and SMA correlators for maximum uniform resolution observations

• I've heard that the peak data rate = X MB/sec (from where does this limit arise?)
• If true, then the peak data rate per baseline = (X MB/sec) / 2016 baselines = X/2.016 kB/sec
• If I want 8192 channels * 4 quadrants * 8 bytes (i.e. 4 bytes for real & 4 bytes for imaginary), then I need 262kB per baseline. So I am limited to T=(2016*0.262MB/X) = 528/X second integrations or longer.
• But the minimum dump time is listed as 0.512 seconds, so this implies that X needs to be 1031 MB/sec = 1 GB/sec.

NTC Tours on September 25, 2008

• Instructions for tour guides: There will be two rounds of one-hour tours, each consisting of 4 groups of 9-10 people. You will receive a color-coded handheld sign to help assemble your group in the NTC parking lot as they disembark from the bus. There are four stations to be visited in round-robin fashion. A bell will be rung over the radio located in each station by Mary or Penny to denote the end of each period.
• Station hosts:
  • FEIC: Geoff Ediss
  • FEIC LO: Bill Shillue, Eric Breyerton and Kamaljeet Saini (Warm Cartridge Assembly), and Yoshihiro Masui and Juana Banda (Photonics)
  • Correlator: John Webber, Joe Greenberg
  • Band 6: John Effland

NTC Tours on September 25, 2008

• There will be two rounds of one-hour tours, each consisting of 4 groups of 9-10 people.
• Laurie will distribute color-coded handheld signs to help the tour guides assemble their group.
• There are four stations to be visited by each group in round-robin fashion.
• A bell will be rung over the radio located in each station by Mary or Penny to denote the end of each period (6:13PM, etc.).
• Nevertheless, we should synchronize our watches in case of technical difficulties.
• Station hosts:

• Instructions for tour guides: There will be two rounds of one-hour tours, each consisting of 4 groups of 9-10 people. You will receive a color-coded handheld sign to help assemble your group in the NTC parking lot as they disembark from the bus. There are four stations to be visited in round-robin fashion. A bell will be rung over the radio located in each station by Mary or Penny to denote the end of each period.
• Station hosts:

• 6 PM tour (Immediately form the groups in the parking lot as people disembark the first bus. Start early if possible.)

• 7 PM tour (The guides listed below should start gathering up people in the courtyard at 6:55. No food is allowed inside the NTC labs.)

• Bell should be rung over the radio by Mary or Penny at the end of each period (6:13PM, etc.)

• There will be two rounds of one-hour tours, each consisting of 4 groups of 9-10 people.
• Laurie will distribute color-coded handheld signs to help the tour guides assemble their group.
• There are four stations to be visited by each group in round-robin fashion.
• A bell will be rung over the radio located in each station by Mary or Penny to denote the end of each period (6:13PM, etc.).
• Nevertheless, we should synchronize our watches in case of technical difficulties.

• • FEIC LO: Bill Shillue and Kamaljeet Saini (Warm Cartridge Assembly), and Yoshihiro Masui and Juana Banda (Photonics)

• • FEIC LO: Bill Shillue, Eric Breyerton and Kamaljeet Saini (Warm Cartridge Assembly), and Yoshihiro Masui and Juana Banda (Photonics)

• 6 PM tour (immediately form the groups as people get off the bus in the parking lot)

• 6 PM tour (Immediately form the groups in the parking lot as people disembark the first bus. Start early if possible.)

• 7 PM tour (The guides should start gathering up people in the courtyard at 6:55. No food is allowed inside the NTC labs.)

• 7 PM tour (The guides listed below should start gathering up people in the courtyard at 6:55. No food is allowed inside the NTC labs.)

SMA data showing odd periodic amplitude drops

SMA data showing odd periodic amplitude drops

In our very extended configuration datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations, but this does not seem to have made any difference. It is worth noting that the effect is not seen in our 345 GHz track taken several days earlier, which used -s128. Plots of the effect are shown below.

• August 17 LSB
• August 17 LSB (zoom to 20 minutes)
• August 17 USB
• August 19 LSB
• August 19 USB
• August 19 USB (zoom to 20 minutes of data)

Significant SMA Sgr B2 observations

• with at least 6 antennas, and 60 minutes

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Significant SMA Sgr B2 observations

• Bell should be rung over the radio by Mary at the end of each period (6:13PM, etc.)

• Bell should be rung over the radio by Mary or Penny at the end of each period (6:13PM, etc.)

Todd's scratch area

Todd's scratch area wikipage

NTC Tours on September 25, 2008

• Bell should be rung over the radio by Mary at the end of each period (6:13PM, etc.)
• Station hosts:
  • FEIC: Geoff Ediss
  • FEIC LO: Bill Shillue and Kamaljeet Saini (Warm Cartridge Assembly), and Yoshihiro Masui and Juana Banda (Photonics)
  • Correlator: John Webber, Joe Greenberg
  • Band 6: John Effland
• 6 PM tour (immediately form the groups as people get off the bus in the parking lot)

• 7 PM tour (The guides should start gathering up people in the courtyard at 6:55. No food is allowed inside the NTC labs.)

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations, but this does not seem to have made any difference. It is worth noting that the effect is not seen in our 345 GHz track taken several days earlier, which used -s128. Plots of the effect are shown below.

In our very extended configuration datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations, but this does not seem to have made any difference. It is worth noting that the effect is not seen in our 345 GHz track taken several days earlier, which used -s128. Plots of the effect are shown below.

SMA data

SMA data showing odd periodic amplitude drops

-Todd

Significant SMA Sgr B2 observations

• with at least 6 antennas, and 60 minutes

%META:FILEATTACHMENT{name="FlashPro.prc" attr="" comment="for Palm Vx" date="1220589004" path="FlashPro.prc" size="48552" user="ToddHunter" version="1.1"}% %META:FILEATTACHMENT{name="FPSetup.prc" attr="" comment="for Palm Vx" date="1220589023" path="FPSetup.prc" size="22450" user="ToddHunter" version="1.1"}%

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations. It is worth noting that the effect is not seen in our 345 GHz track taken 2 weeks earlier, which used -s128. Plots of the effect are shown below.

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations, but this does not seem to have made any difference. It is worth noting that the effect is not seen in our 345 GHz track taken several days earlier, which used -s128. Plots of the effect are shown below.

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations. It is worth noting that the effect is not seen in our 345 GHz track taken 2 weeks earlier, which used -s128. Plots of the effect are shown below.

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed the bright source 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines, as seen in the table below. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations. It is worth noting that the effect is not seen in our 345 GHz track taken 2 weeks earlier, which used -s128. Plots of the effect are shown below.

• August 17 LSB (zoom)

• August 17 LSB (zoom to 20 minutes)

• August 19 LSB
• August 19 USB
• August 19 USB (zoom to 20 minutes of data)

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• [[][August 17]]
• [[][August 19]]

• August 17 LSB
• August 17 LSB (zoom)
• August 17 USB

-Todd

-Todd

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• Phone: 304-456-2157

• GB Phone: 304-456-2157
• CV Phone: 434-244-6836

• Location: GreenBankWV
• Comment:

• Location: GreenBankWV and CharlottesvilleVA

Todd's scratch area

SMA data

In the very extended datasets obtained at 220/230 GHz on August 17 and August 19, 2008, we see an odd effect in the amplitudes. The effect is most pronounced during the part of the tracks when we observed 3c454 continuously for over an hour. Every nth sample shows a small (5%) drop in amplitude. For 3c454, which is about 25 Jy, the drop amounts to ~1 Jy. The value of n seems to be larger for the shorter baselines. On both nights, we used correlator mode -s256. The effect is seen in both sidebands. On the first night, we used 15 second integrations, while on the second night we used 20 second integrations. It is worth noting that the effect is not seen in our 345 GHz track taken 2 weeks earlier, which used -s128. Plots of the effect are shown below.

• [[][August 17]]
• [[][August 19]]

-Todd

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%META:TOPICINFO{author="ToddHunter" date="1164980566" format="1.0" version="1.1"}% %META:TOPICPARENT{name="TWikiUsers"}%

• Name: Todd Hunter
• Login Name: thunter
• Email: thunter@nrao.edu
• Phone: 304-456-2157
• Department: Scientific Services
• Location: GreenBankWV
• Comment:

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