#SOLAR WALK 2 FOR WINDOWS WINDOWS#

Where is the observer-object-sun angle, in degrees. PHASE is used for solar phase angle, and is used to find times when the angular phase of one body as seen from another is within a specified range.

#SOLAR WALK 2 FOR WINDOWS WINDOWS#

SIZE is used to select windows based on the apparent angular diameter of an object in arc-seconds. Positive values of mean that the objects are moving away from each other while negative values mean that the objects are moving closer to each other. R_VEL is used to select windows based on the change in distance between two objects (i.e. When is local minimum ( MIN) or local maximum ( MAX), then is interpreted as a tolerance relative to local minimum or maximum inflection points rather than as an absolute angular rate. If is specified, then is interpreted as the apparent angular rate of relative to as observed from. When is greater than ( GT) or less than ( LT), then is interpreted as the apparent angular rate of as observed from - unless is also specified. This requirement is used to select windows based on the angular rate of objects in terms of arcsec/sec. RANGE is used to select windows based on the separation of objects in terms of distance (AU). When the is MAX ( MIN), then times are found when “objects 1 and 2” are at maximum elongation ( minimum separation), as viewed from. The interpretation of the SEP keyword is as follows: when the is either LT or GT then times are found when the separation of “objects 1 and 2”, as viewed from, is less than or greater than respectively. The units for “angle” must be chosen from one of D (degrees), ' (arc-minutes), or ' (arc-seconds). Where, , and must be standard targets that have been previously defined in the target position fields. The separation between two bodies is defined as the angle between the closest points on the observed limbs of the spheres representing the objects as viewed from the observer (the radius of the sphere is equal to the largest radius of the tri-axial ellipsoid representation of the object). SEP is short for “Separation” and is used to find the times when the apparent separation between two objects, as observed from a third object, satisfies certain conditions. NOT A_VEL IO RELATIVE JUPITER FROM EARTH GT 10 SEP The operator NOT, if present, should precede the keyword for the solar system target observing window, as in these examples: Each of the above keywords may be preceded by the NOT operator May be used to specify when a condition does not exist. Accompanied by a non-zero tolerance value Table 3.24: Keywords for Observing Windows Table 3.25: Operators for Observing Windows contains the list of operators that can be used to define a window. The various keywords used to define windows are given in Table 3.24: Keywords for Observing Windows and described in detail below. This leads to uncertainty in the exact timing of the target “availability” windows more than two or three months in advance.

Note that atmospheric drag and other effects make it difficult to predict the exact position of the HST in its orbit far in advance. However, the proposer must recognize that proposer-supplied windows might not overlap with the target “availability” windows defined above (calculated by STScI), in which case the observation cannot be scheduled. to observe when a satellite is near elongation, to observe when the central meridian longitude lies in a particular range, etc.), then these conditions must be specified in the Window field. If you require other specific conditions to be satisfied (e.g. Those can actually be removed if required. Some of these windows are enforced by Default Target Windows (see list near the bottom of this article). the feature is on that part of the body “facing” HST). If the target is a surface feature on a body, the times when the feature is within the field of view of the HST (i.e.If the target is a planetary satellite, the times when it is not occulted by any other object in the planetary system.Times when the target is not too close to the Sun, Moon, or the bright Earth limb.Times when the target is not occulted by the Earth.In general, “windows” which define when the target is visible to HST need not be explicitly identified, since these windows will be calculated by the STScI. Red text indicates restricted parameters (for STScI use only).īrown text indicates text file parameters. Magenta text indicates available but unsupported parameters (requires prior approval from STScI). Boldface type indicates the name of an APT parameter or a value for a parameter.

Solar walk 2 for windows