# Section 5. High Speed Photometer¶

Calibrations that may be applied to High Speed Photometer (HSP) files include (1) nonlinearity correction due to dead time in digital data, (2) dark signal subtraction, (3) current-to-voltage converter (CVC) offset subtraction for analog data, (4) pre-amplifier signal subtraction, (5) division of high voltage factor due to the detector’s different efficiency at different high voltage setting, (6) division of gain factor due to the detector’s different current gain at different gain setting for analog data, and (7) division of detector efficiency due to possibly slight difference in different apertures sharing the same filter. The reference tables described in this document are used to supply these calibration quantities.

In addition, when an extended target is observed, the count rate per unit area may be preferred, and thus an aperture area reference table is needed. Also, each detector has designated spots used to calibrate the dark signals. A cross-reference table between these dark apertures and regular apertures is also used to carry out the calibration of HSP.

## 5.1 HSP Reference Relations and STSDAS Tables¶

### 5.1.1 Aperture Areas Table: <*unique name*>.CV0¶

The aperture areas table contains the names and areas of all the HSP’s apertures and is used by the HSP calibration. The aperture names are the same as those used to retrieve data from the .CV4 and .CV9 tables; thus every aperture retrieved from the . CV0 table must have an entry in the . CV4 table and one in the .CV9 table. The .CV0 table is loaded only from the project data base tape.

**Format:** Each entry contains an aperture name and an aperture area, which
is used to convert HSP count rates into count rates per square
arc-second. Additionally, there is a POINTER field that is a dummy field
and is not used to hold data.

Table 5-1 shows the structure of the aperture areas table.

**Table 5-1. HSP Aperture Areas Table, <unique name>. CV0**

Column Name | Data Type | Units | Description |
---|---|---|---|

APER_NAME | CH*10 | – | Name of aperture (SOGS aperture naming convention) |

POINTER | I | – | Not used |

APER_SIZE | D | arcsec2 | Aperture area |

### 5.1.2 High Voltage Factor Table: < *unique name*>.CV1¶

The high voltage factor table contains the coefficients and base values used in computing the high voltage detector characteristic (H) for the HSP calibration.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP detector high voltage setting (command value) and data
type. In each set there are a base value, a reference time, a reference
temperature, and 16 polynomial coefficients. Additionally, there is a
POINTER field that is a dummy field and is not used to hold data.

**Selection Scheme:** Records are selected on the basis of detector number,
type (ANALOG or DIGITAL), and high voltage setting.

**Restrictions:** In the high voltage factor table, there should be entries
for the three standard voltage settings (corresponding to photoelectric
current gains of 0.5E+6, 1.0E+6, and 2.0E+6) for each detector and data
type (ANALOG/DIGITAL).

The STSDAS table produced is called <*unique name*>.CV0; Table 5-2 shows
its structure.

**Table 5-2. HSP High Voltage Factor Table, <unique name>. CV1**

Column Name | Data Type | Units | Description |
---|---|---|---|

DET_NUM | I | digital number | Detector number, 1-5 |

TYPE | CH*7 | none | ANALOG, DIGITAL |

VOLTAGE | I | digital number | High voltage setting (command value) |

POINTER | I | – | Not used |

BASE_VALUE | R | none | Base value of the characteristic scaling polynomial |

BASE_TEMP | R | deg Celsius | Base temperature of the characteristic scaling polynomial |

BASE_TIME | D | MJD | Base time of the characteristic scaling polynomia l(Modified Julian Date) |

A00 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A01 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A02 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A03 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A10 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A11 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A20 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A21 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A30 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

A31 | D | deg-3 day-1 | 3,1st coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 day-2 | 3,2nd coefficient of the characteristic scaling polynomial |

A33 | D | deg-3 day-3 | 3,3rd coefficient of the characteristic scaling polynomial |

### 5.1.3 Gain Factor Table: <*unique name*>.CV2¶

The gain factor table contains the coefficients and base values used to compute the gain detector characteristic (G) for the HSP calibration.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP detector and a gain setting (command value). In each set
there are a base value, a reference time, a reference temperature, and
16 polynomial coefficients.

**Selection Scheme:** Records are selected on the basis of detector number
and gain setting.

**Restrictions:** In the gain factor table, for each detector there should
be entries for each of the five gain settings (0, 2, 3, 6, and 7).

Table 5-3 shows the structure of the HSP gain factor table.

**Table 5-3. HSP Gain Factor Table, <unique name>. CV2**

Column Name | Data Type | Units | Description |
---|---|---|---|

DET_NUM | I | digital number | Detector number, 1-5 |

VGAIND | I | digital number | Gain setting: 0, 2, 3, 6, 7 |

BASE_VALUE | R | DN/(counts/sec) | Base value of the characteristic scaling polynomial |

BASE_TEMP | R | deg Celsius | Base temperature of the characteristic scaling polynomial |

BASE_TIME | D | MJD | Base time of the characteristic scaling polynomial |

A00 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A01 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A02 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A03 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A10 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A11 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A20 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A21 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A30 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

A31 | D | deg-3 day-1 | 3,1st coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 day-2 | 3,2nd coefficient of the characteristic scaling polynomial |

A33 | D | deg-3 day-3 | 3,3rd coefficient of the characteristic scaling polynomial |

### 5.1.4 Pre-amp Table: <*unique name*>.CV3¶

The pre-amp table contains the coefficients and base values used in computing the pre-amplifier detector characteristic (E) for the HSP calibration. The PRE AMP detector characteristic (E) is the contribution to the digital count rate or analog current from the electronics.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP detector and data type. In each set there are a base
value, a reference time, a reference temperature, and 16 polynomial
coefficients.

**Selection Scheme:** Records are selected on the basis of detector number
and data type

(ANALOG or DIGITAL).

**Restrictions:** In the pre-amp table, there should be an entry for each
detector and data type

(ANALOG/DIGITAL). Table 5-4 shows the structure of the HSP pre-amp table.

**Table 5-4. HSP Pre-amp Table, <unique name>. CV3**

Column Name | Data Type | Units | Description |
---|---|---|---|

DET_NUM | I | digital number | Detector number, 1-5 |

TYPE | CH*7 | none | ANALOG, DIGITAL |

BASE_VALUE | R | none | Base value of the characteristic scaling polynomial |

BASE_TEMP | R | deg Celsius | Base temperature of the characteristic scaling polynomial |

BASE_TIME | D | MJD | Base time of the characteristic scaling polynomial |

A00 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A01 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A02 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A03 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A10 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A11 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A20 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A21 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A30 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

A31 | D | deg-3 day-1 | 3,1st coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 day-2 | 3,2nd coefficient of the characteristic scaling polynomial |

A33 | D | deg-3 day-3 | 3,3rd coefficient of the characteristic scaling polynomial |

### 5.1.5 Efficiency Table: <*unique name*>.CV4¶

The efficiency table contains the coefficients and base values used in computing the efficiency (relative sensitivity) detector characteristic (R) for the HSP calibration.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP aperture and detector. In each set there are point and
extended base values, a reference time, a reference temperature, and 16
polynomial coefficients.

****Selection Scheme:** Records are selected on the basis of detector
number and aperture name. Table 5-5 shows the structure of STSDAS table
<*unique name*>.CV4.

**Table 5-5. HSP Efficiency Table, <unique name>. CV4**

Column Name | Data Type | Units | Description |
---|---|---|---|

APER_NAME | CH*10 | None | Aperture name identifier |

DET_NUM | I | digital number | Detector number, 1-5 |

VGAIND | I | digital number | Gain setting: 0, 2, 3, 6, 7 |

BASE_VALUE_P | R | none | Point source base value of the characteristic scaling polynomial |

BASE_VALUE_E | R | none | Extended source base value of the characteristic scaling polynomial |

BASE_TEMP | R | deg Celsius | Base temperature of the characteristic scaling polynomial |

BASE_TIME | D | MJD | Base time of the characteristic scaling polynomial |

A00 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A01 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A02 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A03 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A10 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A11 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A20 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A21 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A30 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

A31 | D | deg-3 day-1 | 3,1st coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 day-2 | 3,2nd coefficient of the characteristic scaling polynomial |

A33 | D | deg-3 day-3 | 3,3rd coefficient of the characteristic scaling polynomial |

### 5.1.6 Dark Count Table: <*unique name*>.CV5¶

The dark count table contains the coefficients and base values used in computing the dark count characteristic (D) for the HSP calibration.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP dark aperture, a high voltage setting (command value),
and data type. In each set there are a base value, a reference time, a
reference temperature, and 16 polynomial coefficients. Additionally,
there is a POINTER field that is a dummy field and is not used to hold
data.

**Selection Scheme:** Records are selected on the basis of dark aperture
name, data type
(ANALOG or DIGITAL), and high voltage setting (command value).

**Restrictions:** In the dark count table, there should be entries for the
three standard voltage settings (corresponding to photoelectric current
gains of 0.5E+6, 1.0E+6, and 2.0E+6) for each dark aperture and data
type (ANALOG/DIGITAL).

Table 5-6 shows the structure of the STSDAS table <*unique name*>.CV5.

**Table 5-6. HSP Dark Count Table, <unique name>. CV5**

Column Name | Data Type | Units | Description |
---|---|---|---|

APER_NAME | A33 | D | deg-3 day-1 |

TYPE | CH*10 | D | deg-3 day-2 |

VOLTAGE | CH*7 | None | deg-3 day-3 |

POINTER | I | NONE | Dark aperture name identifier |

BASE_VALUE | I | digital number | ANALOG, DIGITAL |

BASE_TEMP | R | – | High voltage setting (command value) Not used |

BASE_TIME | R | Counts/sec | Base value of the characteristic scaling polynomial |

A00 | D | deg Celsius | Base temperature of the characteristic scaling polynomial |

A01 | D | MJD | Base time of the characteristic scaling polynomial |

A02 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A03 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A10 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A11 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A20 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A21 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A30 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A31 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

### 5.1.7 Time Bias Table: < *unique name*>.CV6¶

The time bias table contains the time biases that are used to correct the integration time for internal instrument delays.

**Format:** Each entry contains a time bias for a particular HSP data format
(BYTE, WORD, LWRD, ALOG, or ALL) and for a particular instrument mode
(SCP, ARS, SSP1, or SSP2).

**Selection Scheme:** Records are selected on the basis of data format and
instrument mode. **Restrictions:** For each instrument mode there should be
entries for each of the five data formats. Table 5-7 shows the structure
of the HSP time bias table.

**Table 5-7. HSP Time Bias Table, <unique name>. CV6**

Column Name | Data Type | Units | Description |
---|---|---|---|

DATA_FMT | CH*4 | none | Data format |

MODE | CH*4 | none | Instrument mode |

TIME_BIAS | I | clock count | Internal instrument delay added to integration times |

### 5.1.8 CVC Offset Table: <*unique name*>.CV7¶

The CVC offset table contains the coefficients used in computing the current-to-voltage converter (CVC) offset detector characteristic (I) for the HSP calibration.

**Format:** Each set of base values and coefficients corresponds to a
particular HSP detector and analog gain setting (command value). In each
set there are a base value, a reference time, a reference temperature,
and 16 polynomial coefficients.

**Selection Scheme:** Records are selected on the basis of detector number
and gain setting.

**Restrictions:** In the CVC offset table, for each detector there should be
entries for each of the five gain settings (0, 2, 3, 6, and 7).

Table 5-8 shows the structure of the HSP CVC offset table.

**Table 5-8. HSP CVC Offset Table, <unique name>. CV7**

Column Name | Data Type | Units | Description |
---|---|---|---|

DET_NUM | I | digital number | Detector number, 1-5 |

VGAIND | I | digital number | Gain setting: 0, 2, 3, 6, 7 |

BASE_VALUE | R | digital number | Base value of the characteristic scaling polynomial |

BASE_TEMP | R | deg Celsius | Base temperature of the characteristic scaling polynomial |

BASE_TIME | D | MJD | Base time of the characteristic scaling polynomial |

A00 | D | none | 0,0th coefficient of the characteristic scaling polynomial |

A01 | D | day-1 | 0,1st coefficient of the characteristic scaling polynomial |

A02 | D | day-2 | 0,2nd coefficient of the characteristic scaling polynomial |

A03 | D | day-3 | 0,3rd coefficient of the characteristic scaling polynomial |

A10 | D | deg-1 | 1,0th coefficient of the characteristic scaling polynomial |

A11 | D | deg-1 day-1 | 1,1st coefficient of the characteristic scaling polynomial |

A12 | D | deg-1 day-2 | 1,2nd coefficient of the characteristic scaling polynomial |

A13 | D | deg-1 day-3 | 1,3rd coefficient of the characteristic scaling polynomial |

A20 | D | deg-2 | 2,0th coefficient of the characteristic scaling polynomial |

A21 | D | deg-2 day-1 | 2,1st coefficient of the characteristic scaling polynomial |

A22 | D | deg-2 day-2 | 2,2nd coefficient of the characteristic scaling polynomial |

A23 | D | deg-2 day-3 | 2,3rd coefficient of the characteristic scaling polynomial |

A30 | D | deg-3 | 3,0th coefficient of the characteristic scaling polynomial |

A31 | D | deg-3 day-1 | 3,1st coefficient of the characteristic scaling polynomial |

A32 | D | deg-3 day-2 | 3,2nd coefficient of the characteristic scaling polynomial |

A33 | D | deg-3 day-3 | 3,3rd coefficient of the characteristic scaling polynomial |

### 5.1.9 Dead Time Table: < *unique name*>.CV8¶

The dead time table contains the coefficients and base values in computing the dead time (tau), which is used for paired-pulse corrections in HSP calibration.

**Format:** Each set of base values and coefficients corresponding to a
particular HSP detector, high voltage setting (command value), and pulse
amplifier/discriminator (PAD) threshold setting (command value). In each
set there are a base value, a reference temperature, and one

coefficient.

**Selection Scheme:** Records are selected on the basis of detector number,
high voltage setting, and PAD threshold setting.

**Restrictions:** In the dead time table, there should be entries for the
three standard high voltage settings (corresponding to photoelectric
current gains of 0.5E+6, 1.0E+6, 2.0E+6) for each detector and PAD
threshold setting(s) (usually one).

Table 5-9 shows the structure of the HSP dead time table.

**Table 5-9. HSP Dead Time Table, <unique name>. CV8**

Column Name | Data Type | Units | Description |
---|---|---|---|

DET_NUM | I | digital number | Detector number, 1-5 |

VOLTAGE | I | digital number | High voltage setting (command value) |

THRESH | I | digital number | PAD threshold setting (command value) |

BASE_VALUE | R | sec | Base value of dead time |

A1 | R | sec/deg | Dead time temperature dependence coefficient |

BASE_TEMP | R | deg | Celsius Temperature zero point used in temperature dependence |

### 5.1.10 Dark Aperture Table: <*unique name*>.CV9¶

The dark aperture table contains the corresponding dark aperture names for each of the regular HSP aperture names. The dark aperture names are later used to calibrate HSP dark counts.

**Format:** Each regular HSP aperture name has a corresponding dark aperture
name. Each image dissector tube (IDT) has three dark apertures, and the
photo-multiplier (PMT) has one dark aperture name.

**Selection Scheme:** Records are selected on the basis of aperture name and
detector number.

**Restrictions:** The dark aperture table may contain aperture names that
refer to the same aperture as another name. In this case, the redundant
names are eliminated by setting both to the same name.

Table 5-10 shows the structure of the dark aperture table.

**Table 5-10. HSP Dark Aperture Translation Table, <unique name>. CV9**

Column Name | Data Type | Units | Description |
---|---|---|---|

APER_NAME | CH*10 | none | Regular aperture name |

DET_NUM | I | digital number | Detector number |

DARK_APER | CH*10 | none | Dark aperture name |