NEO Planner V5.0  -  Execute Planning  -  Explanations


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Within the picture, click on the area that you want to be explained: (not in all browsers available)

Origin: The data comes from official access to web services from MPC and Horizons System

 

QHY600L:

Active camera. Clicking takes you to the CCD parameters and you can select the active camera there.

With comets y/n  V = -30 to xx.x:

Select here whether you want to include comets in the planning or not. Select the weakest magnitude down to which objects should be considered.

Neo Planner calculates observation times in R.A. order of currently visible comets according to the official publication of the MPC
and additionally the most recently observed comets from CometasObs.
The reason for including the CometasObs observations lies in the sometimes considerable delay of the MPC in the publication of the last observations.

More information on the inclusion of comets in the planning process can be found here.

With comets, compared to NEO, you have to apply slightly different standards with regard to the Vmag selection.
Since comets usually appear spotty on the CCD image,
the maximum usable brightness should be set somewhat higher than with NEO. In addition, comets move at far greater distances from the Earth,
which largely excludes a significant change in measured brightness.
29P SCHWASSMANN/WACHMANN with its regularly occurring outbursts in brightness is certainly an exception here just like outbreaks in other comets,
but is generally not taken into account.

The real brightness of comets is actually often very different from the brightness we find in the ephemeris of the MPC.
Therefore to calculate the exposure times, NEO Planner always uses the average Vmag of the last 10 observations,
which are determined from the last publishing by the MPC
with MPEC XXX: OBSERVATIONS AND ORBITS OF COMETS AND A / OBJECTS.

With NEO y/n  V = -xx.x to xx.x:

Select here whether you want to include NEO the planning or not. Select the weakest magnitude down to which objects should be considered.
Entering N/n also means that numbered NEO will not be considered. Select the weakest magnitude down to which objects should be considered.

As a rule, every NEO observer has experience with the maximum NEO observable for him in relation to their brightness
and should therefore enter his personal experience value here.
NEO Planner will therefore only select those objects whose Vmag values are numerically below the settings value.
The apparent speed does not play a role at this point when considering the maximum usable brightness.

The following model is used to select the NEO:

First it is checked whether the Vmag of the ephemeris is maximum 0.4 mag weaker than the limit value in the settings.
If so, the object will continue to be considered.

Second, if the apparent speed in the ephemeris is less than 100.00 s / min, the average Vmag of the last 10 observations
 is used for the selection of the object,
otherwise the Vmag of the ephemeris.

The reason for taking into account the apparent speed at the time of the ephemeris is a possible strong change
in the Vmag compared to previous observations..
At speeds over 100 seconds / minute at the time of the ephemeris we always use MPC's designated Vmag of the ephemeris for selection.
Otherwise fast objects might not be taken into account.

In additon, during the calculation of the exposure times, the selected NEO are subjected to a special Vmag consideration.
See the explanations for the revise button in the Preparation / Execute Planning tab

NEO from year:

NEO with provisional designations are always included in the planning. Enter the starting year of designations of objects not yet numbered.

These objects have not yet been finally numbered and require further follow-up observations. Recently discovered NEO,
 in particular, require further observation to improve their orbital elements.
The uncertainty factor U plays a special role in the orbital elements. Objects with a U factor of 3 or greater
cannot be safely recovered in coming orbits. U = 0 is the best value.
It is therefore a special and valuable task for amateurs to help improve the orbital elements of the NEO.

NEO to year:

Enter the final year of designations of objects not yet numbered.

With numbered NEO y/n  V = xx.x to xx.x:

Select here whether you want to include numbered asteroids the planning or not. Select the weakest magnitude down
to which objects should be considered.

Numbered objects are not in the foreground of the observation priorities. However, there may be reasons for observing objects
whose orbit is very well known.
In the case of numbered NEOs such as 99944 Apophis or other asteroids that are passing very close to Earth,
there may well be an interest in tracking such NEOs.
In particular, to make meaningful videos for presentation purposes or for other reasons, it can make perfect sense
also to follow such objects.
In addition, around the full moon there is a good opportunity for diligent observers to include numbered NEOs
in the list to compensate for the lack of other objects.

That is why NEO Planner offers the option of including numbered objects in the selection.

The determination of the observable NEO per observatory code is no longer carried out via the NEAm00.txt of the MPC,
but via the new API Web Service of the Horizons system of the JPL.
This significantly reduces the loading time of the NEO's ephemeris, which is good for the overall performance of the Execute process.
The loading of all observable numbered NEO of the coming night is now carried out according to the parameters defined
by NEO Planner such as minimum altitude or limitation of magnitude.
If numbered objects are selected, please also enter a limit for the magnitude V here.

All NEOCP object with V = -30 to  xx.x:

Confirming NEOCP objects is both a motivation and a challenge. Experience has shown that observers pay special attention to these objects.
The confirmation of new objects, but also the follow-up observation, is important in order to allow as many measurements as possible to flow into
the calculation of the orbital elements for a retrieval in later orbits.

Hint: The MPC always shows the current positions and brightness of the objects on the NEOCP.
However, there may be significant fluctuations in brightness at the times planned with NEO Planner.
It is therefore advisable to enter slightly weaker brightnesses than usual for NEOCP objects

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The following orbit classes can now also be integrated into the planning.
However, attention should be paid to a narrow selection of brightnesses and not planned to be mixed with other classes.
Otherwise there is a risk of very long planning times.

With orbit type Mars Crossers  MCA y/n  V = xx.x to xx.x  with numbered y/n:

Asteroids that cross the orbit of Mars constrained by (1.3 au < q < 1.666 au; a < 3.2 au).
In order to avoid very long loading times, it is advisable to limit the selected objects using narrow Vmag from..to entries.
In addition, no other objects should be integrated into the planning.

With orbit type Jupiter Trojans  TJN y/n  V = xx.x to xx.x  with numbered y/n:

Asteroids trapped in Jupiter�s L4/L5 Lagrange points (4.6 au < a < 5.5 au; e < 0.3).
In order to avoid very long loading times, it is advisable to limit the selected objects using narrow Vmag from..to entries.
Jupiter Trojans are very numerous and mostly already numbered.
To avoid frustration with the length of time planning or program crashes this orbit class
should be selected with only unnumbered objects or set the Vmag range very narrow: e.g. Vmag from 19.0 to Vmag 19.3

In addition, no other objects should be integrated into the planning.

With orbit type Centaur  CEN y/n  V = xx.x to xx.x  with numbered y/n:

Objects with orbits between Jupiter and Neptune (5.5 au < a < 30.1 au).
In order to avoid very long loading times, it is advisable to limit the selected objects using narrow Vmag from..to entries.
In addition, no other objects should be integrated into the planning.

With orbit type TransNeptunian Object  TNO y/n  V = xx.x to xx.x  with numbered y/n:

Objects with orbits outside Neptune (a > 30.1 au).
In order to avoid very long loading times, it is advisable to limit the selected objects using narrow Vmag from..to entries.
In addition, no other objects should be integrated into the planning.

With orbit type Hyperbolic <Asteroid>  HYA y/n  V = xx.x to xx.x  with numbered y/n:

<Asteroids> (objects other than comets) on hyperbolic orbits (e > 1.0).
This orbit class is very rare and should only be of interest when interstellar objects are newly discovered.

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With own object list y/n:

Depending on the interest, the observer can create his own object list with any asteroids,
which can be included in the planning selection area.
Application examples are the self-discovered numbered asteroids, which mostly come from the main belt,
or discovered objects that are not yet numbered.

With the help of this function, a previously popular follow-up list of your own objects is no longer necessary.
T
hese objects are included in the planning process and taken into account in the final list,
if the selection was successful according to the settings parameters.

Execute start 'auto', empty of special date and time:

If you enter "auto", the local start time of the planning is determined from the current GeoSetting data.
First the current sunset and sunrise times are loaded.
Then the offset times from the common restrictions settings are used to calculate the start and end times.
In the Revise planning display, this data is displayed as observation slot start and end times.
The calculated start time is used when planning the observation of the first object. Times can be adjusted in the Revise window.
Always use 'auto' when you call up planning for the night session.
Adjustments to the start time can then be made in the Revise Window via the 'Smart Planning' function.

New in version 4.2: To simulate other observation days, leave the 'auto' field empty
and enter the desired planning date in local time in the form 'yyyy.MM.dd hh mm ss'.
NEO Planner then calculates the planning data for the date entered. Example:
Simulation of a plan from April 13, 2029, the close flyby of (99942) Apophis, as shown in the image.

Moon restrictions

By activating the switch, no moon distance parameters are taken into account in the planning.

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ExecutePlanning:

Attention: The planning for the upcoming night session can only be done after 9 a.m. local time.
All planning before 9 a.m. refers to the previous night session.

The planning according to the settings and the parameters selected here takes place in differentiated steps,
which are processed one after the other.
The planning process can be followed in the web browser on the right and in the progress bar.

First the objects of the current NEOCP are loaded and the observable objects are selected from them.
Then, together with the observable comets, NEO, numbered and own objects selected above,
the ephemeris of the coming night session is determined.
After sorting all objects according to R.A. the planning is provided and then the observation times are calculated according to the settings.
The result of the planning can then be displayed in the Revise and Object Information Window, edited and, if desired,
made available on a website.

After the planning has been completed, interface data like Xml and JSON are created
in the Daily Planning Archive folder, which in N.I.N.A. can be loaded via the sequencer funktion.
There is also a .txt file release of the planning for the ACP Observatory Control Software for your own use.

The Execute Planning parameters for the selected camera are saved and reloaded when the camera is reused.
This means you can now create up to 30 different scenarios in the CCD/CMOS settings and use them in Execute Planning.
Example: Full moon settings with scenario QHY600L Full Moon period. There are no limits to the various scenarios, except for the maximum limit of 30.

 

Center position:

In the Execute Planning Window you now have the option to choose between two types of centering objects for the FoV.
 a. Centering the object's start position to the center of the FoV (as before).
 b. Centering the middle position of the object path to the center of the FoV.

By centering on the middle of the object path, you get a much longer path of fast objects per frame.
The adjusted middle positions are also taken into account in the JSON interface for N.I.N.A. 
 and the path is displayed correctly in the Execute Search window.

Revise Planning:

In planning is displayed here in the calculated order and provides information about the objects that can be reached for the coming night.
In addition to the transit time of the object, the observation time calculated on the basis of the parameters is displayed.
In addition, the planning suggests the exposure times and the number of images per object.
Here you can also revise and save the planning, e.g. to display it on a website.

NEOCP Check:

The NEOCP Check function enables the planning to be updated quickly, including the current NEOCP display.
It is checked whether there are updates for individual NEOCP objects,
whether these have been deleted or an M.P.E.C. publication took place.
If new provisional numbers are assigned, these will be determined and displayed.

Rejected objects:

Display of rejected objects in a new window. After every scheduling will update the display.
In the 'Rejected objects' window you can activate rejected objects and start a new planning there.

 

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New calculation method of the number of images per stack, conceived by Heiko Duin, L65 Bredenkamp Observatory, Bremen:

Switch in the CCD Settings to use a new calculation method for the number of exposures per object:

The number of images with longer maximum exposure times (e.g. 120 or 180 seconds) and shorter maximum exposure times (e.g. 30 or 15 seconds)
are now calculated correctly. Compared to the previous method, this shortens the number of images with longer exposure time
and increases the number of shots of slow objects and short exposure time.

Reference values of K87:

href_exposures = 50 Reference value Number of images
href_reso = 3.2 Reference value Resolution FWHM
href_velo = 16.6 Reference value s/min
href_sb = 18.74 Reference value Sky Background SB of NEO Planner
href_mag = 19.4 Reference value Vmag object
href_beltotal = 500 Reference value Total exposure time in seconds for one measurement

Station values:

sref_reso = resFWHM Station value Resolution FWHM
sref_sb = skybackground Station value Sky Background SB of NEO Planner
sref_maxexp = maxexp Station value maximum exposure time in seconds

Formula Visual Basic:

step1 = sref_reso / velocity(obj) * 60

step2a = href_mag - Vmag(obj)
step2b = href_sb - sref_sb
step2c = step2a - step2b

step3 = 1 / (2.512 ^ step2c)
step4 = href_beltotal * step3

If step1 > sref_maxexp Then
step5 = sref_maxexp
Else
step5 = step1
End If

step6 = CInt(Math.Floor(step4 / step5)) + 1
total number of exposures = step6 * number of groups

Heiko's method is more elegant and mathematically precise than my old method.


The minimum number of images per stack is 1.

Both methods make it possible to calculate the necessary image sequences independently of the equipment.
 

I would like to add one important hint. Objects of the solar system, regardless of their type,
have different albedos due to their chemical and physical properties.
So it is perfectly normal that a carbon-rich asteroid is harder to astrometry than a ferrous one.
The same is true for highly condensed comas in comets as compared to less strongly condensed comas.
However, NEO Planner cannot know the albedo of the individual objects.
Therefore everyone has to expect that the observation can go wrong due to too few images in the stack.

For years I have been observing NEO and comets with my formula and have achieved useful results.
Both the reference data and the formulas therefore have a certain practical value, and by no means a scientific one.

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Taking airmass and magnitude extinction into account (scientifically, all objects)

Useful when humidity is low and/or there is little or no light brightening the horizon.

When the checkbox is activated, the relative airmass of the location is taken into account
when calculating the number of images per group/stack.
The altitude of the object at the time of observation is used.
The consideration of airmass and moon-sky background is only calculated at altitudes above the minimum value in the Common Restrictions.

The values used to calculate the airmass come from the JPL HORIZONS API, here is the description:

_RELATIVE_ optical airmass and magnitude extinction:

Airmass is the ratio of the absolute optical airmass at the targets refracted
elevation angle with the absolute optical airmass at zenith.
Also output is the estimated visual magnitude extinction due to atmosphere, as seen by the observer. (end of description)
Source: Description HORIZONS API Quantity 8

The formula for calculating the airmass is (source: Heiko Duin, L65 Bredenkamp Observatory, Bremen):

mag_ex = estimated visual magnitude extinction
a-mass = _RELATIVE_ optical airmass

extf = mag_ex / a-mass
factor = 10 ^ ((a-mass - 1) * extf / 2.512)

The number of images calculated by NEO Planner is now multiplied by the factor.

Airmass is used together with the Sky brightness due to moonlight value if the checkboxes of both values are activated.
Both values are gradually integrated, otherwise only the activated value or none.
The airmass is multiplied by the number of calculated images per group/stack using floating point numbers.
Thus, the total number of images is increased during planning.

The calculation of the number of images including airmass and lunar sky brightness is carried out using floating point numbers.
This means that it is not always possible to derive the number per group/stack in Revise. Please take this fact into account!
The more images per group are originally required, the more accurate the result will be.

 

Integration of airmass and horizontal conditions (practically, all objects)

Useful when humidity is high and/or there is light brightening the horizon.

When the checkbox is activated, the relative airmass of the location is taken into account
when calculating the number of images per group/stack.
The altitude of the object at the time of observation is used.
The consideration of airmass and moon-sky background is only calculated at altitudes above the minimum value in the Common Restrictions.

However, the value determined for the airmass does not take the local conditions into account.
Humidity and increasing light pollution near the horizon can negatively affect observations of objects at larger zenith angles.

So, the value _RELATIVE_ optical airmass from the JPL HORIZONS API is best suited for this fact:

Airmass is the ratio of the absolute optical airmass at the targets refracted
elevation angle with the absolute optical airmass at zenith. Source: Description HORIZONS API Quantity 8

The number of images calculated by NEO Planner is now multiplied by a-mass.

Airmass is used together with the Sky brightness due to moonlight value if the checkboxes of both values are activated.
Both values are gradually integrated, otherwise only the activated value or none.
The airmass value is multiplied by the number of calculated images per group/stack using floating point numbers.
Thus, the total number of images is increased during planning.

The calculation of the number of images including airmass and lunar sky brightness is carried out using floating point numbers.
This means that it is not always possible to derive the number per group/stack in Revise. Please take this fact into account!
The more images per group are originally required, the more accurate the result will be.

 

Difference and connection between both methods:

Source: Heiko Duin, Bremen

Illustration of the difference between the two airmass methods.
The blue line shows the course of the expansion factor when the horizon brightens at the observatory (practically),
the orange line shows the extension factor without horizon brightening (scientifically).
The extf-0.2801 value corresponds to an extf at sea level. (see Reference, Table 1a)

Explanations about Airmass and Extinction (by Heiko Duin):

Extinction is given as a coefficient per airmass in magnitudes, so the extinction for an object with an angle z from the zenith is:
airmass * ext_factor, where airmass depends on z. Extinction depends on many factors, e.g. humidity and altitude above sea level
and is therefore difficult to calculate directly for a given location and weather conditions.
Fortunately, the HORIZONS interface also provides Airmass and Extinction in the ephemerides (a_mass and mag_ex).
These are determined according to the Obs code, so we don't have to worry about altitude above sea level.
From the HORIZONS data you can easily determine the extinction coefficient with extf = mag_ex / a_mass (in mag).
The reference measurement from K87 resulted in a specific magnitude for an object.
However, in photometry the measured value is calculated to be “above the atmosphere”.
This means that (at least) one airmass was already taken into account when measuring on K87.
Therefore, only (Airmass – 1) needs to be taken into account when calculating the extension factor.
If you now convert mag into flux and put everything together, you get the extension factor vlf:

vlf = 10^((am-1)*extf/2.5) = 10^-((1-am)*extf/2.5)
am = airmass

This corresponds to the orange curve in the diagram, while the blue curve indicates the associated airmass.
The extinction coefficient value of 0.28 comes from Green (1992) (http://www.icq.eps.harvard.edu/ICQExtinct.html)
and is an average extinction coefficient for a site on normal Zero level.
Light pollution does not affect extinction, at least I haven't found any evidence of it.
The extension due to light pollution is controlled by the background value (in mag per square arcsecond).

Reference: Green D. W. E. Correcting for Atmospheric Extinction, July 1992

 

 

Taking the Lunar Sky Brightness into account (all objects)

When the checkbox is activated, the Sky brightness due to moonlight and the position of the object in the sky
is taken into account when calculating the number of images per group/stack.

The value is determined from the JPL HORIZONS API, here is the description:

Sky brightness due to moonlight scattering by Earth's atmosphere at the target's position in the sky.
Output only for topocentric Earth observers when both the Moon and target are above
the local horizon and the Sun is in astronomical twilight (or further) below the horizon.
Galactic brightness, local sky light-pollution and weather are NOT considered.
Lunar opposition surge is considered. The value returned is accurate under ideal conditions
at the approximately 8-23% level, so is a useful but not definitive value. Source: Description HORIZONS API Quantity 48

Sky brightness due to moonlight is used together with the airmass value if the checkboxes of both values are activated.
Both values are gradually integrated, otherwise only the activated value or none.
The lunar sky brightness is multiplied by the number of calculated images per group/stack using floating point numbers.
Thus, the total number of images is increased during planning.

The calculation of the number of images including airmass and lunar sky brightness is carried out using floating point numbers.
This means that it is not always possible to derive the number per group/stack in Revise. Please take this fact into account!
The more images per group are originally required, the more accurate the result will be.

If activated, it is no longer necessary to increase the groups in Revise in disturbing moonlight.

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Copyright: The author of NEO Planner and all sites of this web is Bernhard Haeusler, Dettelbach, Germany, all rights reserved