| Description: The HEAO-1 spacecraft was launched into low earth orbit on 12 August, 1977. Its orbit was very nearly circular with an apogee of 445 km, inclination of 22.75°, and orbital period of 93 minutes. During the bulk of the mission, the spacecraft operated in a scanning mode in which it rotated with a period of 35 minutes, scanning out great circles of constant ecliptic longitude. Every twelve hours, the spin axis would be realigned with the Sun, adjusting the longitude of the great circle by roughly half a degree. Thus, afte1r six months, the spacecraft would have scanned the entire sky. After the first 100 days, the scanning was interupted periodically to performed pointed observations. These pointings became more frequent until 9 January, 1979, when the attitude control gas supply ran out. The satellite re-entered the Earth's atmosphere on 14 March, 1979. <p> HEAO-1 was equipped with four instrument packages. This file contains an all-sky map made from roughly six months of scanning data from the A2 instrument. T |
| Completely compliant |
| Service URL |
| Input Parameter | Required | Present |
|---|---|---|
| Regular parameters: | ||
| POS | MUST | Yes |
| SIZE | MUST | Yes |
| INTERSECT | MAY | No |
| NAXIS | MAY | Yes |
| CFRAME | MAY | Yes |
| EQUINOX | MAY | Yes |
| CRPIX | MAY | No |
| CRVAL | MAY | No |
| CDELT | MAY | No |
| ROTANG | MAY | No |
| PROJ | MAY | Yes |
| FORMAT | MUST | Yes |
| Service specific parameters | ||
| INTERPOLATION | MAY | Yes |
| big | MAY | Yes |
| small | MAY | Yes |
| Field UCD | Required | Present | Required datatype |
Actual datatype |
|---|---|---|---|---|
| Regular fields: | ||||
| VOX:Image_Title | MUST | Yes | char | char |
| INST_ID | SHOULD | No | char | |
| VOX:Image_MJDateObs | SHOULD | No | double | |
| POS_EQ_RA_MAIN | MUST | Yes | double | double |
| POS_EQ_DEC_MAIN | MUST | Yes | double | double |
| VOX:Image_Naxes | MUST | Yes | int | int |
| VOX:Image_Naxis | MUST | Yes | int | int |
| VOX:Image_Scale | MUST | Yes | double | double |
| VOX:Image_Format | MUST | Yes | char | char |
| VOX:STC_CoordRefFrame | SHOULD | No | char | |
| VOX:STC_CoordEquinox | MAY | No | double | |
| VOX:WCS_CoordProjection | SHOULD | No | char | |
| VOX:WCS_CoordRefPixel | SHOULD | No | double | |
| VOX:WCS_CoordRefValue | SHOULD | No | double | |
| VOX:WCS_CDMatrix | SHOULD | No | double | |
| VOX:BandPass_ID | SHOULD | No | char | |
| VOX:BandPass_Unit | SHOULD | No | char | |
| VOX:BandPass_RefValue | SHOULD | No | double | |
| VOX:BandPass_HiLimit | SHOULD | No | double | |
| VOX:BandPass_LoLimit | SHOULD | No | double | |
| VOX:Image_PixFlags | SHOULD | Yes | char | char |
| VOX:Image_AccessReference | MUST | Yes | char | char |
| Service specific fields: | ||||
| VOX:LogicalName | MAY | YES | char | |